[top]
000
FXUS62 KRAH 072343
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
743 PM EDT THU MAY 7 2009
.SYNOPSIS...
A MOIST AND UNSTABLE AIR MASS COUPLED WITH A SURFACE TROUGH IN THE
VICINITY WILL TRIGGER SCATTERED AFTERNOON AND EVENING THUNDERSTORMS
THROUGH SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 235 PM THURSDAY...
AIR MASS CONTINUES TO DESTABILIZE AS MIXED LAYER CAPE AT 17Z AROUND
1500 J/KG AND SURFACE BASED LIFTED INDICES AROUND MINUS 5/MINUS 6
AND LOW LEVEL LAPSE RATES APPROACHING 8 DEG C/KM. 0-6KM BULK SHEAR
35-40KTS NOT SHABBY WITH WIND PROFILE FAIRLY UNIDIRECTIONAL. THESE
PARAMETERS SUGGEST THAT CELLS SHOULD EVENTUALLY INTO BROKEN LINE.
DAMAGING DOWNBURSTS AND LARGE HAIL APPEAR TO BE THE MAIN SEVERE
WEATHER FACTORS AS O-1KM HELICITY LESS THAN 100 M2/SEC2 AND LCL
HEIGHTS GENERALLY AT OR ABOVE 1000M. AT 1820Z...ALREADY SEEING
ISOLATED CELLS DEVELOP ALONG THE BLUE RIDGE AND ON A NARROW ZONE OF
SURFACE CONFLUENCE FROM LAURINBURG TO GOLDSBORO TO WILSON. EXPECT
THUNDERSTORM COVERAGE TO INCREASE IN COVERAGE AFTER 20-21Z AS MID
LEVEL TROUGH OVER THE LOWER OH-TN VALLEY ADVANCES EAST. WHILE
MAJORITY OF CONVECTION WILL DISSIPATE WITH LOSS OF HEATING...MAY SEE
SCATTERED CONVECTION PERSIST UP TO 04Z IN THE EAST AS THIS REGION
WILL BE IN THE FAVORABLE LEFT EXIT REGION OF 300MB JET OVER THE TN
VALLEY. FOR NOW...WILL GO WITH A SOLID CHANCE POP LATE THIS
AFTERNOON/EARLY EVENING WITH SLIGHT CHANCE POP IN THE EAST BY 04Z.
SKIES WILL BECOME MOSTLY CLEAR IN WAKE OF CONVECTION. MOIST LOW
LEVEL AIR MASS SHOULD ALLOW POCKETS OF FOG AND/OR STRATUS TO DEVELOP
BY DAYBREAK. MINS TONIGHT MAINLY IN THE MID 60S.
&&
.SHORT TERM /FRIDAY/...
AS OF 240 PM THURSDAY...
FRIDAY...CONDITIONALLY UNSTABLE AIR MASS WILL REMAIN ON PLACE BUT
FOCUS FOR CONVECTIVE DEVELOPMENT ASIDE FROM INSOLATION WILL NOT
ARRIVE UNTIL LATE IN THE DAY OR AFTER SUNSET. EXPECT SCATTERED
CONVECTION TO FIRE WITH A FEW STORMS BRIEFLY SEVERE LATE IN THE DAY.
STEADY SW FLOW AND DECENT INSOLATION WILL MAKE IT FEEL LIKE EARLY
SUMMER. LOW LEVEL THICKNESSES TOP OUT NEAR 1410M. PREVIOUS FORECAST
OF MID/UPPER 80S LOOKS ON TARGET.
&&
.LONG TERM TERM /FRIDAY NIGHT THROUGH THURSDAY/...
AS OF 340 PM THURSDAY...
WARM SOUTHWEST FLOW OVER THE AREA FRIDAY NIGHT WILL RESULT IN
CONTINUATION OF UNSETTLED WEATHER SATURDAY AS WE REMAIN IN WARM
SECTOR... WITH BOUNDARY ALONG THE NORTH CAROLINA/VIRGINIA BORDER.
LOWS FRIDAY NIGHT WILL BE IN THE 60S. HIGHS SATURDAY WILL BE IN THE
80S WITH LOWER 90S ACROSS THE SOUTH AND EAST.
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA LATE SATURDAY
AFTERNOON/SATURDAY EVENING... LINGERING SOUTH OF THE AREA THROUGH
EARLY MONDAY. UPPER LEVEL WESTERLY FLOW OVERRUNNING THE NORTHEAST
SURFACE COULD ENHANCE PRECIPITATION ESPECIALLY OVER THE SOUTHERN
PORTION OF THE CWA. ALSO THE WESTERLY FLOW WILL AID IN PUSHING THE
MERCURY UPWARDS. LOWS SATURDAY NIGHT WILL BE IN THE 60S... DROPPING
INTO THE 50S SUNDAY NIGHT. HIGHS SUNDAY WILL BE IN THE 70S NORTH TO
LOWER 80S SOUTH... COOLING TO THE 70S MONDAY.
HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE NORTHWEST MONDAY
EVENING... AND REMAIN ENTRENCHED ALONG THE ATLANTIC SEABOARD THROUGH
WEDNESDAY MORNING. AS THE HIGH MOVES EAST AND SOUTHEAST WEDNESDAY
NIGHT AND THURSDAY... MOISTURE WILL INCREASE ACROSS THE WEST AND
NORTH. HIGHS TUESDAY THROUGH THURSDAY WILL BE IN THE 70S... EXCEPT
FOR SOME LOWER 80S ACROSS THE SOUTHEAST ON THURSDAY. LOWS WILL BE IN
THE 50S TUESDAY NIGHT AND WEDNESDAY NIGHT.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 745 PM THURSDAY...
A MOIST AND CONDITIONALLY UNSTABLE AIR MASS WILL REMAIN IN PLACE
ACROSS CENTRAL NC THROUGH THE WEEKEND. THIS WILL RESULT IN MAINLY
VFR CONDITIONS WITH PERIODS OF MVFR/IFR DUE TO SCATTERED AFT/EVE
CONVECTION AND EARLY MORNING FOG AND/OR STRATUS.
ISOLD CONVECTION REMAINS POSSIBLE ACROSS ALL OF CENTRAL NC THIS
EVENING INTO THE OVERNIGHT HOURS (THROUGH ROUGHLY 06Z) IN ASSOC/W A
QUICK MOVING MID-LEVEL IMPULSE CURRENTLY (AS OF 00Z) APPROACHING
WESTERN NC. OTHER THAN THE POSSIBILITY OF BRIEF MVFR/IFR CONDITIONS
IN AN ISOLATED SHOWER/STORM...EXPECT VFR CONDITIONS THROUGH 06Z.
THERE WILL BE A POSSIBILITY OF MVFR/IFR FOG BETWEEN 08-12Z FRI
MORNING AT ALL TAF SITES. OTHERWISE...EXPECT PREDOMINATELY VFR CONDS
THROUGH THE TAF PERIOD. EXPECT ANY CONVECTION FRIDAY AFTERNOON TO
HOLD OFF UNTIL LATE IN THE DAY (AFTER 21Z). MAY SEE CONVECTION
PERSIST A BIT LONGER FRIDAY NIGHT AS UPPER LEVEL TROUGH CROSSES
REGION.
THE MOIST AND UNSTABLE AIR MASS WILL PERSIST ACROSS THE REGION
THROUGH EARLY NEXT WEEK. A LINGERING SURFACE BOUNDARY WILL HELP TO
INITIATE SCATTERED CONVECTION EACH AFTERNOON/EVENING. THIS WILL
RESULT IN PERIODS OF MVFR/IFR CONDITIONS. -VINCENT/WSS
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS
SHORT TERM...WSS
LONG TERM...RHJ
AVIATION...VINCENT/WSS
[top]
000
FXUS62 KILM 072328
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
725 PM EDT THU MAY 7 2009
.SYNOPSIS...
WARMER AND DRIER WEATHER WILL PREVAIL ON FRIDAY AND SATURDAY AS
ATLANTIC HIGH PRESSURE RIDGES BACK INTO THE REGION. A COLD FRONT
WILL MOVE INTO THE AREA ON SUNDAY AND STALL THROUGH MONDAY. THIS
FRONT WILL FINALLY MOVE OUT OF THE AREA LATE MONDAY BRINGING
SLIGHTLY COOLER AND DRIER AIR THROUGH MID WEEK...AS HIGH PRESSURE
BUILDS INTO THE REGION FROM THE NORTH THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM THURSDAY...SUBSIDENCE DRIER AIR HAS OVERSPREAD THE AREA
THIS AFTERNOON AND WITH LACK UP TRIGGERS ALOFT AND SURFACE
FEATURES...OTHER THAN SEABREEZE BOUNDARY...NOT SURE HOW WIDESPREAD
CONVECTION WILL BE THROUGH THE EVENING HOURS. AT THIS TIME...EXPECT
ISOLATED TO SCATTERED THUNDERSTORMS WILL DEVELOP GIVEN HEATING OF
THE DAY. THUNDERSTORMS WILL DIMINISH WITH LOSS OF HEATING AND SHOULD
COME TO AN END BETWEEN 9 AND 11P. SOME THUNDERSTORMS MAY BECOME
STRONG WITH GUSTY WINDS GIVEN DRY AIR IN THE MID LEVELS AND SMALL
HAIL AS WET BULB ZEROS BEGIN TO LOWER INTO THIS EVE. NOT IMPOSSIBLE
FOR AN ISOLATED OCCURRENCE OF DAMAGING WIND OR LARGE HAIL INTO THIS
EVE AND SPC HAS MAINTAINED THEIR OUTLOOK FOR A SLIGHT RISK FOR
SEVERE THUNDERSTORMS WHICH INCLUDE THE ILM FORECAST AREA.
AS AIRMASS STABILIZES LATER THIS EVE AND OVERNIGHT...WINDS WILL
BECOME LIGHT AND WITH THAT AND GIVEN THE WET GROUND...PATCHY FOG
MAY DEVELOP AS TEMPS AND DEWPOINTS CLOSE THE GAP. BEST CHANCE FOR
THIS WILL BE ACROSS INLAND AREAS TOWARD FRI MORNING. TEMPS WILL
AGAIN BE BALMY TONIGHT AS SIMILAR AIRMASS OF LAST FEW DAYS REMAINS
IN PLACE. DIMINISHING CLOUD COVER AND LIGHTER WINDS SHOULD ALLOW FOR
SLIGHTLY BETTER COOLING THAN LAST NIGHT...SO PERHAPS A FEW LESS
LOWER 70S THAN THU MORNING.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...ATLANTIC HIGH PRESSURE WILL RIDGE BACK INTO
THE SOUTHEAST FRI AND SAT. AREA REMAINS IN A ZONAL FLOW WITH A
ONLY A FEW RIPPLES PASSING THROUGH IT. A SHORTWAVE WILL MOVE
MAINLY NORTH OF THE AREA LATE FRI WHICH MAY HELP TO ENHANCE OR
PRODUCE SOME SHWRS/TSTMS FRI AFTN ALONG THE PIEDMONT TROUGH AND
SEA BREEZE BOUNDARY. OVERALL NOT EXPECTING TOO MUCH SHWR/TSTM
ACTIVITY THROUGH SAT. FOCUSED POPS INLAND FRI AFTN WITH LIMITED TO
NO ACTIVITY EXPECTED ALONG THE COAST. LEFT OUT MENTION OF POPS FOR
SAT. THE SHORT TERM PERIOD WILL BASICALLY BE DEFINED BY VERY WARM
WEATHER WITH TEMPS RUNNING 5 TO 10 DEGREES ABOVE NORMAL. EXPECT
CLOUDS MAINLY OVER INLAND COUNTIES ON FRI AND MORE SUNSHINE FOR
SAT. TOWARD THE END OF THE PERIOD...HEADING INTO SAT NIGHT...A
COLD FRONT APPROACHES FROM THE WEST. GFS/NAM BRING FRONT INTO CWA
BY SUN MORNING BUT NOT SHOWING MUCH IN THE WAY OF PCP WITH IT. FOR
NOW WILL KEEP OUT MENTION OF ANY POPS OVERNIGHT SAT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...PROGRESSIVE ZONAL FLOW EARLY IN THE
EXTENDED PERIOD WILL BECOME MORE AMPLIFIED AS A TROUGH DIGS INTO
THE EASTERN CONUS BY TUESDAY. AT THE SURFACE...A STALLED FRONTAL
BOUNDARY WILL REMAIN DRAPED ACROSS THE CWA UNTIL EARLY
MONDAY...WHEN HIGH PRESSURE WILL BUILD IN FROM THE NW AND PUSH IT
WELL OFFSHORE. THE ELONGATED SURFACE HIGH WILL SETTLE OVER THE
EASTERN SEABOARD BY WEDNESDAY... AND H5 HEIGHTS WILL BEGIN TO RISE
AS AN UPPER RIDGE AXIS SHIFTS ACROSS THE APPALACHIANS.
THE FRONTAL BOUNDARY SHOULD ACT AS A FOCUSING MECHANISM FOR
SCATTERED CONVECTION SUNDAY AND SUNDAY NIGHT...BUT THE BETTER CHANCE
OF PRECIP SHOULD BE MONDAY AND MONDAY NIGHT ASSOCIATED WITH THE
PASSAGE OF A H7 SHORTWAVE. SUBSIDENCE BEHIND THE SHORTWAVE SHOULD
INHIBIT PRECIP POTENTIAL TUE-WED.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
SHOWERS IN THE VICINITY OF CRE AND ILM BUT ONLY FOR ABOUT THE NEXT
HOUR. GENERALLY VFR FOR THE REMAINDER OF THE 24HR TAF CYCLE AS ONLY
CIGS IN THE NEAR TERM WILL BE CIRRUS DEBRIS FROM CONVECTION. AREAS
OF 5KFT CIGS MAY DEVEL IN SOME AREAS OVERNIGHT. MVFR VSBY POSSIBLE
AT CRE TOWARDS PREDAWN HOURS. SLIGHT DIURNAL WIND TREND AS WELL WITH
A DECREASE NEXT HOUR OR TWO AND A SLIGHT INC IN THE SW WINDS AFTER
DAYBREAK FRI.
EXTENDED OUTLOOK THROUGH MONDAY...ISOLATED THUNDERSTORMS THROUGH
SATURDAY. SCATTERED THUNDERSTORMS SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM THURSDAY...REPLACED SMALL CRAFT ADVISORY WITH EXERCISE
CAUTION HEADLINE AND WILL INCLUDE AN EXERCISE CAUTION FOR ALL WATERS
INTO THIS EVE AND FOR OVERNIGHT FOR AMZ250-252. PRESSURE GRADIENT
DOES NOT CHANGE ALL THAT MUCH...SO WINDS IN 15 TO 20 KT RANGE FROM
THE SW ARE EXPECTED TO PERSIST. SE SWELL 8/9 SECONDS IS STILL
EVIDENT AND IS NOT EXPECTED TO CHANGE THROUGH THE PERIOD. WILL CAP
SEAS AT 5 FT WITH 6 FOOTERS POSSIBLE OUT AROUND FRYING PAN SHOALS.
NEAR SHORE WATERS WILL RANGE FROM 2 TO 4 FT...HIGHEST ACROSS THE
BRUNSWICK NEAR SHORE WATERS.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...HIGH PRESSURE WILL RIDGE BACK INTO LOCAL AREA
THROUGH THE PERIOD MAINTAINING S-SW FLOW. SPEEDS SHOULD REMAIN
AROUND 15 KTS THROUGH FRI...BUT GRADIENT TIGHTENS HEADING INTO SAT
AND EXPECT SW WINDS TO INCREASE TO NEAR 20 KTS BY SAT AFTN. OVERALL
SEAS SHOULD REMAIN 3 TO 4 FT ON FRI...BUT ON SAT WITH INCREASED
FLOW...WOULD EXPECT SEAS TO INCREASE INTO THE 3 TO 6 FT
RANGE...POSSIBLY WARRANTING A SCEC OR SCA.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 3 PM THURSDAY...A STALLED FRONTAL BOUNDARY IS EXPECTED TO BE
DRAPED ALONG THE COAST SUNDAY AND EARLY MONDAY...RESULTING IN A LOW
CONFIDENCE WIND DIRECTION FORECAST. HOWEVER LATER MONDAY...THE FRONT
WILL GET PUSHED OFFSHORE AS HIGH PRESSURE BUILDS IN FROM THE
NW...AND A NORTHERLY COMPONENT WILL BECOME PREDOMINANT BY MONDAY
AFTERNOON.
SCATTERED SHOWERS AND TSTMS WILL BE POSSIBLE IN ASSOCIATION WITH THE
FRONTAL BOUNDARY SUNDAY-SUNDAY NIGHT. COVERAGE IS EXPECTED TO
INCREASE MONDAY AS A SHORTWAVE MOVES ACROSS THE AREA.
A MODEST GRADIENT SHOULD RESULT IN SUSTAINED WINDS 15 KT OR LESS
SUNDAY THROUGH MONDAY. MONDAY NIGHT INTO EARLY TUESDAY...THE
GRADIENT TIGHTENS UP AS THE HIGH BEGINS TO BUILD TOWARDS THE
COAST...BUT DIMINISHES AGAIN BY TUESDAY AFTERNOON.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RGZ
NEAR TERM...RJD
SHORT TERM...RGZ
LONG TERM...CRM
AVIATION...MBB
000
FXUS62 KRAH 071941
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
340 PM EDT THU MAY 7 2009
.SYNOPSIS...
A MOIST AND UNSTABLE AIR MASS COUPLED WITH A SURFACE TROUGH IN THE
VICINITY WILL TRIGGER SCATTERED AFTERNOON AND EVENING THUNDERSTORMS
THROUGH SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 235 PM THURSDAY...
AIR MASS CONTINUES TO DESTABILIZE AS MIXED LAYER CAPE AT 17Z AROUND
1500 J/KG AND SURFACE BASED LIFTED INDICES AROUND MINUS 5/MINUS 6
AND LOW LEVEL LAPSE RATES APPROACHING 8 DEG C/KM. 0-6KM BULK SHEAR
35-40KTS NOT SHABBY WITH WIND PROFILE FAIRLY UNIDIRECTIONAL. THESE
PARAMETERS SUGGEST THAT CELLS SHOULD EVENTUALLY INTO BROKEN LINE.
DAMAGING DOWNBURSTS AND LARGE HAIL APPEAR TO BE THE MAIN SEVERE
WEATHER FACTORS AS O-1KM HELICITY LESS THAN 100 M2/SEC2 AND LCL
HEIGHTS GENERALLY AT OR ABOVE 1000M. AT 1820Z...ALREADY SEEING
ISOLATED CELLS DEVELOP ALONG THE BLUE RIDGE AND ON A NARROW ZONE OF
SURFACE CONFLUENCE FROM LAURINBURG TO GOLDSBORO TO WILSON. EXPECT
THUNDERSTORM COVERAGE TO INCREASE IN COVERAGE AFTER 20-21Z AS MID
LEVEL TROUGH OVER THE LOWER OH-TN VALLEY ADVANCES EAST. WHILE
MAJORITY OF CONVECTION WILL DISSIPATE WITH LOSS OF HEATING...MAY SEE
SCATTERED CONVECTION PERSIST UP TO 04Z IN THE EAST AS THIS REGION
WILL BE IN THE FAVORABLE LEFT EXIT REGION OF 300MB JET OVER THE TN
VALLEY. FOR NOW...WILL GO WITH A SOLID CHANCE POP LATE THIS
AFTERNOON/EARLY EVENING WITH SLIGHT CHANCE POP IN THE EAST BY 04Z.
SKIES WILL BECOME MOSTLY CLEAR IN WAKE OF CONVECTION. MOIST LOW
LEVEL AIR MASS SHOULD ALLOW POCKETS OF FOG AND/OR STRATUS TO DEVELOP
BY DAYBREAK. MINS TONIGHT MAINLY IN THE MID 60S.
&&
.SHORT TERM /FRIDAY/...
AS OF 240 PM THURSDAY...
FRIDAY...CONDITIONALLY UNSTABLE AIR MASS WILL REMAIN ON PLACE BUT
FOCUS FOR CONVECTIVE DEVELOPMENT ASIDE FROM INSOLATION WILL NOT
ARRIVE UNTIL LATE IN THE DAY OR AFTER SUNSET. EXPECT SCATTERED
CONVECTION TO FIRE WITH A FEW STORMS BRIEFLY SEVERE LATE IN THE DAY.
STEADY SW FLOW AND DECENT INSOLATION WILL MAKE IT FEEL LIKE EARLY
SUMMER. LOW LEVEL THICKNESSES TOP OUT NEAR 1410M. PREVIOUS FORECAST
OF MID/UPPER 80S LOOKS ON TARGET.
&&
.LONG TERM TERM /FRIDAY NIGHT THROUGH THURSDAY/...
AS OF 340 PM THURSDAY...
WARM SOUTHWEST FLOW OVER THE AREA FRIDAY NIGHT WILL RESULT IN
CONTINUATION OF UNSETTLED WEATHER SATURDAY AS WE REMAIN IN WARM
SECTOR... WITH BOUNDARY ALONG THE NORTH CAROLINA/VIRGINIA BORDER.
LOWS FRIDAY NIGHT WILL BE IN THE 60S. HIGHS SATURDAY WILL BE IN THE
80S WITH LOWER 90S ACROSS THE SOUTH AND EAST.
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA LATE SATURDAY
AFTERNOON/SATURDAY EVENING... LINGERING SOUTH OF THE AREA THROUGH
EARLY MONDAY. UPPER LEVEL WESTERLY FLOW OVERRUNNING THE NORTHEAST
SURFACE COULD ENHANCE PRECIPITATION ESPECIALLY OVER THE SOUTHERN
PORTION OF THE CWA. ALSO THE WESTERLY FLOW WILL AID IN PUSHING THE
MERCURY UPWARDS. LOWS SATURDAY NIGHT WILL BE IN THE 60S... DROPPING
INTO THE 50S SUNDAY NIGHT. HIGHS SUNDAY WILL BE IN THE 70S NORTH TO
LOWER 80S SOUTH... COOLING TO THE 70S MONDAY.
HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE NORTHWEST MONDAY
EVENING... AND REMAIN ENTRENCHED ALONG THE ATLANTIC SEABOARD THROUGH
WEDNESDAY MORNING. AS THE HIGH MOVES EAST AND SOUTHEAST WEDNESDAY
NIGHT AND THURSDAY... MOISTURE WILL INCREASE ACROSS THE WEST AND
NORTH. HIGHS TUESDAY THROUGH THURSDAY WILL BE IN THE 70S... EXCEPT
FOR SOME LOWER 80S ACROSS THE SOUTHEAST ON THURSDAY. LOWS WILL BE IN
THE 50S TUESDAY NIGHT AND WEDNESDAY NIGHT.
&&
.AVIATION /17Z THURSDAY THROUGH TUESDAY/...
AS OF 103 PM THURSDAY...
A MOIST AND CONDITIONALLY UNSTABLE AIR MASS WILL REMAIN IN PLACE
ACROSS CENTRAL NC THROUGH THE WEEKEND. THIS WILL RESULT IN MAINLY
VFR CONDITIONS WITH PERIODS OF MVFR/IFR DUE TO SCATTERED CONVECTION
AND EARLY MORNING FOG AND/OR STRATUS.
THROUGH 03Z FRI...A WEAK SURFACE TROUGH WILL EDGE SLOWLY EAST ACROSS
CENTRAL NC. AIR MASS AHEAD OF THIS FEATURE WILL CONTINUE TO
DESTABILIZE DUE TO STRONG HEATING. EXPECT TO SEE SCATTERED
CONVECTION TO POP OVER THE WESTERN PIEDMONT BETWEEN 20-22Z WITH
CONVECTION POSSIBLY FORMING INTO A BROKEN LINE BY 22Z. THIS LINE OF
CONVECTION SHOULD PROGRESS EAST INTO THE SANDHILLS AND COASTAL PLAIN
BY 00Z. WITH LOSS OF HEATING...SHOULD SEE CONVECTION DIMINISH
DISSIPATE BY 04Z.
SKIES SHOULD CLEAR AFTER 04Z. COOLING OF MOIST AIR MASS NEAR THE
SURFACE SHOULD RESULT IN FORMATION OF WIDESPREAD FOG AND/OR STRATUS
BY DAYBREAK FRIDAY. FOG/STRATUS SHOULD BURN OFF BY 13Z FRIDAY.
EXPECT VFR CONDITIONS THROUGH MOST OF FRIDAY. EXPECT ANY CONVECTION
FRIDAY TO HOLD OFF UNTIL LATE IN THE DAY (AFTER 21Z). MAY SEE
CONVECTION PERSIST A BIT LONGER FRIDAY NIGHT AS UPPER LEVEL TROUGH
CROSSES REGION.
THE MOIST AND UNSTABLE AIR MASS WILL PERSIST ACROSS THE REGION
THROUGH EARLY NEXT WEEK. A LINGERING SURFACE BOUNDARY WILL HELP TO
INITIATE SCATTERED CONVECTION EACH AFTERNOON/EVENING. THIS WILL
RESULT IN PERIODS OF MVFR/IFR CONDITIONS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS
SHORT TERM...WSS
LONG TERM...RHJ
AVIATION...WSS
[top]
000
FXUS62 KMHX 071932
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
332 PM EDT THU MAY 7 2009
.SYNOPSIS...
A FRONT WILL LINGER WEST OVER CENTRAL NC AND WILL DISSIPATE FRIDAY.
ANOTHER FRONT WILL APPROACH THE AREA SATURDAY AND MOVE OFFSHORE
SUNDAY. THIS FRONT WILL LINGER OFFSHORE THROUGH MONDAY. HIGH
PRESSURE WILL BUILD INTO THE AREA TUESDAY AND WILL REMAIN OVER THE
AREA THROUGH THURSDAY. A FRONT WILL APPROACH FROM THE WEST LATE
THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
LN OF STORMS HAS MV OFFSHORE THIS EARLY AFTN. SW LO LVL FLO UNDR
CLRG SKIES. QUESTION IS...HAS THE AMS BEEN WORKED OVR ENUF TO SPPRS
ANY FURTHER ACTVTY THIS AFTN. WK UPR TROF WL MV THRU WI ANTHR S/WV
TNGT. CUD SEE SUM SHWRS LTR TNGT AS THIS ENERGY SWINGS THRU. WL HV
DCRSG CHCS AFT MIDNGT AS TROF EXITS.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/...
ZNL FLO AT 5H ESTABLISHES ITSELF OVR THE AREA ON FRI. SERIES OF WK
S/WVS WL MV THRU THE FLO INTO THE WKEND. HARD TO KEY ON ANY OF THESE
S/WVS AND TIMING WL BE DIFFICULT TO DETERMINE. GFS/NAM/SREF ALL
FAIRLY DRY IN THE FRI THRU SAT TM PD. HARD TO RULE OUT ANY PCPN IN
THIS TYPE OF PATTERN. WL CARRY SCHC. BEST LUKG S/WV IN MDLS WL BE
FRI AFTN. HI TEMPS WL RMN IN THE 80S FRI AND SAT WI SW LO LVL FLO
CONTG.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
MDLS SHOWG A S/WV MVG THRU THE ZNL FLO WL PUSH A FRNT THRU THE AREA
SAT NGT. FRNT WL BE S OF AREA BY SUN. ANTHR SURGE WL PUSH THRU SUN
AFTN AND NGT. 5H FLO TO BCM MR AMPLIFIED OVR THE ECST MON AND A WV
FRMS ON THE FRNT TO OUR S. CUD SEE SUM OVRRNNG PCPN FRM THIS WV MON
AND MON NGT. HI PRES BOTH AT THE SFC AND ALFT WL BLD IN TUE NGT.
THIS RDG WL MV OFFSHR THU. HI TEMPS IN THE 70S BHND THE FRNT ON MON
WL CLIMB BACK INTO THE LWR 80S BY THU.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
AS OF 330 PM THURSDAY...EXPECTING DIURNAL STRONG/SEVERE
THUNDERSTORMS TO BEGINNING FIRING WITH CONTINUED DESTABILIZATION OF
THE ATMOSPHERE THIS AFTERNOON. THESE STORMS SHOULD BEGIN TO WEAKEN
LATE EVENING AS ATMOSPHERE STABILIZES. A WEAK DISTURBANCE ALOFT
COULD HELP TO SUSTAIN WEAKER CONVECTION OVERNIGHT BUT NOT
EXPECTING THE COVERAGE LIKE LAST NIGHT. THEREFORE WILL CONTINUE A
VFR TAF THROUGH 08Z THEN INDICATE SOME LOW CLOUDS/FOG LATE AS
WINDS BEGIN TO DIMINISH.
THE ATMOSPHERE WILL REMAIN MOIST AND UNSTABLE AND SUPPORTIVE OF
MAINLY AFTERNOON/EVENING STORMS THROUGH SUNDAY. A FRONT WILL CROSS
THE AREA SUNDAY NIGHT WITH LOW PRESSURE FORMING ALONG IT MONDAY
CONTRIBUTING TO A CONTINUED RISK OF SHOWERS OR STORMS. HIGH
PRESSURE WILL BUILD OVER THE AREA TUESDAY WITH DRIER/STABLE AIR.
&&
.MARINE...
AS OF 330 PM THURSDAY...WILL EXTEND ADVISORIES FOR THE
SOUNDS/NORTHERN WATERS THROUGH MID EVENING BASED ON CURRENT
OBSERVATIONS. WINDS SHOULD BEGIN TO DIMINISH LATE AFTER WEAK UPPER
DISTURBANCE PASSES. WINDS FOR THE MOST PART SHOULD REMAIN BELOW 20
KT FRIDAY (BUT SEAS WILL REMAIN 4-6 FT SO THE ADVISORIES WILL
CONTINUE FOR THE WATERS SOUTH OF OREGON INLET) THEN BEGIN TO
INCREASE FRIDAY NIGHT AND ESPECIALLY SATURDAY AS THE NEXT
SHORTWAVE APPROACHES AND INTERACTS WITH THE STATIONARY FRONT TO
THE WEST. THE GFS HAS WINDS TO 30 KT BUT LOOKED TO BE SUFFERING
FROM GRID SCALE FEEDBACK SO WILL CAP WINDS T 25 KT AND SEAS AT 8
FT. WINDS AND WAVES WILL SUBSIDE SUNDAY AS THE FRONT STALLS OVER
THE SOUTHERN WATERS AND THE GRADIENT RELAXES. A WAVE OF LOW
PRESSURE IS FORECAST TO FORM ALONG THE FRONT SUNDAY NIGHT INTO
MONDAY WITH INCREASING NORTHERLY FLOW TO 15 G 20 KT. WILL FORECAST
SEAS TO 3-5 FT TO COINCIDE WITH THIS. HIGH PRESSURE WILL BUILD
OVER THE WATERS ON TUESDAY WITH LIGHT WINDS AND SEAS LESS THAN 4
FT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ135-
150.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT SUNDAY FOR AMZ152-154-156-
158.
&&
$$
SYNOPSIS...CGG
NEAR TERM...CGG
SHORT TERM...CGG
LONG TERM...CGG
AVIATION...JME
MARINE...JME
000
FXUS62 KILM 071924
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
323 PM EDT THU MAY 7 2009
.SYNOPSIS...
WARMER AND DRIER WEATHER WILL PREVAIL ON FRIDAY AND SATURDAY AS
ATLANTIC HIGH PRESSURE RIDGES BACK INTO THE REGION. A COLD FRONT
WILL MOVE INTO THE AREA ON SUNDAY AND STALL THROUGH MONDAY. THIS
FRONT WILL FINALLY MOVE OUT OF THE AREA LATE MONDAY BRINGING
SLIGHTLY COOLER AND DRIER AIR THROUGH MID WEEK...AS HIGH PRESSURE
BUILDS INTO THE REGION FROM THE NORTH THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM THURSDAY...SUBSIDENCE DRIER AIR HAS OVERSPREAD THE AREA
THIS AFTERNOON AND WITH LACK UP TRIGGERS ALOFT AND SURFACE
FEATURES...OTHER THAN SEABREEZE BOUNDARY...NOT SURE HOW WIDESPREAD
CONVECTION WILL BE THROUGH THE EVENING HOURS. AT THIS TIME...EXPECT
ISOLATED TO SCATTERED THUNDERSTORMS WILL DEVELOP GIVEN HEATING OF
THE DAY. THUNDERSTORMS WILL DIMINISH WITH LOSS OF HEATING AND SHOULD
COME TO AN END BETWEEN 9 AND 11P. SOME THUNDERSTORMS MAY BECOME
STRONG WITH GUSTY WINDS GIVEN DRY AIR IN THE MID LEVELS AND SMALL
HAIL AS WET BULB ZEROS BEGIN TO LOWER INTO THIS EVE. NOT IMPOSSIBLE
FOR AN ISOLATED OCCURRENCE OF DAMAGING WIND OR LARGE HAIL INTO THIS
EVE AND SPC HAS MAINTAINED THEIR OUTLOOK FOR A SLIGHT RISK FOR
SEVERE THUNDERSTORMS WHICH INCLUDE THE ILM FORECAST AREA.
AS AIRMASS STABILIZES LATER THIS EVE AND OVERNIGHT...WINDS WILL
BECOME LIGHT AND WITH THAT AND GIVEN THE WET GROUND...PATCHY FOG
MAY DEVELOP AS TEMPS AND DEWPOINTS CLOSE THE GAP. BEST CHANCE FOR
THIS WILL BE ACROSS INLAND AREAS TOWARD FRI MORNING. TEMPS WILL
AGAIN BE BALMY TONIGHT AS SIMILAR AIRMASS OF LAST FEW DAYS REMAINS
IN PLACE. DIMINISHING CLOUD COVER AND LIGHTER WINDS SHOULD ALLOW FOR
SLIGHTLY BETTER COOLING THAN LAST NIGHT...SO PERHAPS A FEW LESS
LOWER 70S THAN THU MORNING.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...ATLANTIC HIGH PRESSURE WILL RIDGE BACK INTO
THE SOUTHEAST FRI AND SAT. AREA REMAINS IN A ZONAL FLOW WITH A
ONLY A FEW RIPPLES PASSING THROUGH IT. A SHORTWAVE WILL MOVE
MAINLY NORTH OF THE AREA LATE FRI WHICH MAY HELP TO ENHANCE OR
PRODUCE SOME SHWRS/TSTMS FRI AFTN ALONG THE PIEDMONT TROUGH AND
SEA BREEZE BOUNDARY. OVERALL NOT EXPECTING TOO MUCH SHWR/TSTM
ACTIVITY THROUGH SAT. FOCUSED POPS INLAND FRI AFTN WITH LIMITED TO
NO ACTIVITY EXPECTED ALONG THE COAST. LEFT OUT MENTION OF POPS FOR
SAT. THE SHORT TERM PERIOD WILL BASICALLY BE DEFINED BY VERY WARM
WEATHER WITH TEMPS RUNNING 5 TO 10 DEGREES ABOVE NORMAL. EXPECT
CLOUDS MAINLY OVER INLAND COUNTIES ON FRI AND MORE SUNSHINE FOR
SAT. TOWARD THE END OF THE PERIOD...HEADING INTO SAT NIGHT...A
COLD FRONT APPROACHES FROM THE WEST. GFS/NAM BRING FRONT INTO CWA
BY SUN MORNING BUT NOT SHOWING MUCH IN THE WAY OF PCP WITH IT. FOR
NOW WILL KEEP OUT MENTION OF ANY POPS OVERNIGHT SAT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...PROGRESSIVE ZONAL FLOW EARLY IN THE
EXTENDED PERIOD WILL BECOME MORE AMPLIFIED AS A TROUGH DIGS INTO
THE EASTERN CONUS BY TUESDAY. AT THE SURFACE...A STALLED FRONTAL
BOUNDARY WILL REMAIN DRAPED ACROSS THE CWA UNTIL EARLY
MONDAY...WHEN HIGH PRESSURE WILL BUILD IN FROM THE NW AND PUSH IT
WELL OFFSHORE. THE ELONGATED SURFACE HIGH WILL SETTLE OVER THE
EASTERN SEABOARD BY WEDNESDAY... AND H5 HEIGHTS WILL BEGIN TO RISE
AS AN UPPER RIDGE AXIS SHIFTS ACROSS THE APPALACHIANS.
THE FRONTAL BOUNDARY SHOULD ACT AS A FOCUSING MECHANISM FOR
SCATTERED CONVECTION SUNDAY AND SUNDAY NIGHT...BUT THE BETTER CHANCE
OF PRECIP SHOULD BE MONDAY AND MONDAY NIGHT ASSOCIATED WITH THE
PASSAGE OF A H7 SHORTWAVE. SUBSIDENCE BEHIND THE SHORTWAVE SHOULD
INHIBIT PRECIP POTENTIAL TUE-WED.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
TERMINALS ARE CURRENTLY VFR. WINDS ARE SOUTHWEST 10-20 KNOTS. GUSTS
TO 20-25 KNOTS WILL BE POSSIBLE AT THE COASTAL TERMINALS BY MID
AFTERNOON.
EXPECT CB/THUNDERSTORM DEVELOPMENT THIS AFTERNOON SOUTHWEST TO SOUTH
OF MYR NEAR THE OLD SURFACE TROUGH. THIS ACTIVITY COULD ADVECT
NORTHEAST INTO THE COASTAL TERMINALS AFTER 21Z. ACTIVITY WILL BE
ISOLATED THUS WILL INDICATE CB/VCSH IN COASTAL TERMINAL TAFS
21Z-00Z.
THUNDERSTORM DEVELOPMENT IS EXPECTED BY 00Z NORTHWEST AND WEST OF
FLO/LBT. THE BEST COVERAGE SHOULD BE NORTHWEST OF LBT. THIS ACTIVITY
WILL MOVE EAST AND COULD AFFECT THE FLO/LBT TERMINALS BY THIS
EVENING. SINCE ACTIVITY IS EXPECTED TO BE ISOLATED WILL ONLY MENTION
CB IN FLO TAF AND CB/VCSH IN LBT TAFS 00Z-06Z. OTHERWISE OVERNIGHT
THERE IS A SLIGHT CHANCE OF IFR VISIBILITIES TO DEVELOP BY 10Z AT
FLO/LBT. DUE TO POSSIBLE BROKEN CLOUD COVER WILL INDICATE MVFR
VISIBILITIES IN TAFS. COASTAL TERMINALS SHOULD REMAIN VFR EXCEPT
SOME TEMPO MVFR VISIBILITIES IN THE PRE-DAWN HOURS ESPECIALLY AT CRE.
TEMPO MVFR CEILINGS EXPECTED FRIDAY MORNING. CEILINGS SHOULD IMPROVE
TO VFR BY MID-MORNING.
EXTENDED OUTLOOK THROUGH MONDAY...ISOLATED THUNDERSTORMS THROUGH
SATURDAY. SCATTERED THUNDERSTORMS SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM THURSDAY...REPLACED SMALL CRAFT ADVISORY WITH EXERCISE
CAUTION HEADLINE AND WILL INCLUDE AN EXERCISE CAUTION FOR ALL WATERS
INTO THIS EVE AND FOR OVERNIGHT FOR AMZ250-252. PRESSURE GRADIENT
DOES NOT CHANGE ALL THAT MUCH...SO WINDS IN 15 TO 20 KT RANGE FROM
THE SW ARE EXPECTED TO PERSIST. SE SWELL 8/9 SECONDS IS STILL
EVIDENT AND IS NOT EXPECTED TO CHANGE THROUGH THE PERIOD. WILL CAP
SEAS AT 5 FT WITH 6 FOOTERS POSSIBLE OUT AROUND FRYING PAN SHOALS.
NEAR SHORE WATERS WILL RANGE FROM 2 TO 4 FT...HIGHEST ACROSS THE
BRUNSWICK NEAR SHORE WATERS.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...HIGH PRESSURE WILL RIDGE BACK INTO LOCAL AREA
THROUGH THE PERIOD MAINTAINING S-SW FLOW. SPEEDS SHOULD REMAIN
AROUND 15 KTS THROUGH FRI...BUT GRADIENT TIGHTENS HEADING INTO SAT
AND EXPECT SW WINDS TO INCREASE TO NEAR 20 KTS BY SAT AFTN. OVERALL
SEAS SHOULD REMAIN 3 TO 4 FT ON FRI...BUT ON SAT WITH INCREASED
FLOW...WOULD EXPECT SEAS TO INCREASE INTO THE 3 TO 6 FT
RANGE...POSSIBLY WARRANTING A SCEC OR SCA.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 3 PM THURSDAY...A STALLED FRONTAL BOUNDARY IS EXPECTED TO BE
DRAPED ALONG THE COAST SUNDAY AND EARLY MONDAY...RESULTING IN A LOW
CONFIDENCE WIND DIRECTION FORECAST. HOWEVER LATER MONDAY...THE FRONT
WILL GET PUSHED OFFSHORE AS HIGH PRESSURE BUILDS IN FROM THE
NW...AND A NORTHERLY COMPONENT WILL BECOME PREDOMINANT BY MONDAY
AFTERNOON.
SCATTERED SHOWERS AND TSTMS WILL BE POSSIBLE IN ASSOCIATION WITH THE
FRONTAL BOUNDARY SUNDAY-SUNDAY NIGHT. COVERAGE IS EXPECTED TO
INCREASE MONDAY AS A SHORTWAVE MOVES ACROSS THE AREA.
A MODEST GRADIENT SHOULD RESULT IN SUSTAINED WINDS 15 KT OR LESS
SUNDAY THROUGH MONDAY. MONDAY NIGHT INTO EARLY TUESDAY...THE
GRADIENT TIGHTENS UP AS THE HIGH BEGINS TO BUILD TOWARDS THE
COAST...BUT DIMINISHES AGAIN BY TUESDAY AFTERNOON.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RGZ
NEAR TERM...RJD
SHORT TERM...RGZ
LONG TERM...CRM
AVIATION...MRR
000
FXUS62 KILM 071923
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
323 PM EDT THU MAY 7 2009
.SYNOPSIS...
WARMER AND DRIER WEATHER WILL PREVAIL ON FRIDAY AND SATURDAY AS
ATLANTIC HIGH PRESSURE RIDGES BACK INTO THE REGION. A COLD FRONT
WILL MOVE INTO THE AREA ON SUNDAY AND STALL THROUGH MONDAY. THIS
FRONT WILL FINALLY MOVE OUT OF THE AREA LATE MONDAY BRINGING
SLIGHTLY COOLER AND DRIER AIR THROUGH MID WEEK...AS HIGH PRESSURE
BUILDS INTO THE REGION FROM THE NORTH THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM THURSDAY...SUBSIDENCE DRIER AIR HAS OVERSPREAD THE AREA
THIS AFTERNOON AND WITH LACK UP TRIGGERS ALOFT AND SURFACE
FEATURES...OTHER THAN SEABREEZE BOUNDARY...NOT SURE HOW WIDESPREAD
CONVECTION WILL BE THROUGH THE EVENING HOURS. AT THIS TIME...EXPECT
ISOLATED TO SCATTERED THUNDERSTORMS WILL DEVELOP GIVEN HEATING OF
THE DAY. THUNDERSTORMS WILL DIMINISH WITH LOSS OF HEATING AND SHOULD
COME TO AN END BETWEEN 9 AND 11P. SOME THUNDERSTORMS MAY BECOME
STRONG WITH GUSTY WINDS GIVEN DRY AIR IN THE MID LEVELS AND SMALL
HAIL AS WET BULB ZEROS BEGIN TO LOWER INTO THIS EVE. NOT IMPOSSIBLE
FOR AN ISOLATED OCCURRENCE OF DAMAGING WIND OR LARGE HAIL INTO THIS
EVE AND SPC HAS MAINTAINED THEIR OUTLOOK FOR A SLIGHT RISK FOR
SEVERE THUNDERSTORMS WHICH INCLUDE THE ILM FORECAST AREA.
AS AIRMASS STABILIZES LATER THIS EVE AND OVERNIGHT...WINDS WILL
BECOME LIGHT AND WITH THAT AND GIVEN THE WET GROUND...PATCHY FOG
MAY DEVELOP AS TEMPS AND DEWPOINTS CLOSE THE GAP. BEST CHANCE FOR
THIS WILL BE ACROSS INLAND AREAS TOWARD FRI MORNING. TEMPS WILL
AGAIN BE BALMY TONIGHT AS SIMILAR AIRMASS OF LAST FEW DAYS REMAINS
IN PLACE. DIMINISHING CLOUD COVER AND LIGHTER WINDS SHOULD ALLOW FOR
SLIGHTLY BETTER COOLING THAN LAST NIGHT...SO PERHAPS A FEW LESS
LOWER 70S THAN THU MORNING.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...ATLANTIC HIGH PRESSURE WILL RIDGE BACK INTO
THE SOUTHEAST FRI AND SAT. AREA REMAINS IN A ZONAL FLOW WITH A
ONLY A FEW RIPPLES PASSING THROUGH IT. A SHORTWAVE WILL MOVE
MAINLY NORTH OF THE AREA LATE FRI WHICH MAY HELP TO ENHANCE OR
PRODUCE SOME SHWRS/TSTMS FRI AFTN ALONG THE PIEDMONT TROUGH AND
SEA BREEZE BOUNDARY. OVERALL NOT EXPECTING TOO MUCH SHWR/TSTM
ACTIVITY THROUGH SAT. FOCUSED POPS INLAND FRI AFTN WITH LIMITED TO
NO ACTIVITY EXPECTED ALONG THE COAST. LEFT OUT MENTION OF POPS FOR
SAT. THE SHORT TERM PERIOD WILL BASICALLY BE DEFINED BY VERY WARM
WEATHER WITH TEMPS RUNNING 5 TO 10 DEGREES ABOVE NORMAL. EXPECT
CLOUDS MAINLY OVER INLAND COUNTIES ON FRI AND MORE SUNSHINE FOR
SAT. TOWARD THE END OF THE PERIOD...HEADING INTO SAT NIGHT...A
COLD FRONT APPROACHES FROM THE WEST. GFS/NAM BRING FRONT INTO CWA
BY SUN MORNING BUT NOT SHOWING MUCH IN THE WAY OF PCP WITH IT. FOR
NOW WILL KEEP OUT MENTION OF ANY POPS OVERNIGHT SAT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...PROGRESSIVE ZONAL FLOW EARLY IN THE
EXTENDED PERIOD WILL BECOME MORE AMPLIFIED AS A TROUGH DIGS INTO
THE EASTERN CONUS BY TUESDAY. AT THE SURFACE...A STALLED FRONTAL
BOUNDARY WILL REMAIN DRAPED ACROSS THE CWA UNTIL EARLY
MONDAY...WHEN HIGH PRESSURE WILL BUILD IN FROM THE NW AND PUSH IT
WELL OFFSHORE. THE ELONGATED SURFACE HIGH WILL SETTLE OVER THE
EASTERN SEABOARD BY WEDNESDAY... AND H5 HEIGHTS WILL BEGIN TO RISE
AS AN UPPER RIDGE AXIS SHIFTS ACROSS THE APPALACHIANS.
THE FRONTAL BOUNDARY SHOULD ACT AS A FOCUSING MECHANISM FOR
SCATTERED CONVECTION SUNDAY AND SUNDAY NIGHT...BUT THE BETTER CHANCE
OF PRECIP SHOULD BE MONDAY AND MONDAY NIGHT ASSOCIATED WITH THE
PASSAGE OF A H7 SHORTWAVE. SUBSIDENCE BEHIND THE SHORTWAVE SHOULD
INHIBIT PRECIP POTENTIAL TUE-WED.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
TERMINALS ARE CURRENTLY VFR. WINDS ARE SOUTHWEST 10-20 KNOTS. GUSTS
TO 20-25 KNOTS WILL BE POSSIBLE AT THE COASTAL TERMINALS BY MID
AFTERNOON.
EXPECT CB/THUNDERSTORM DEVELOPMENT THIS AFTERNOON SOUTHWEST TO SOUTH
OF MYR NEAR THE OLD SURFACE TROUGH. THIS ACTIVITY COULD ADVECT
NORTHEAST INTO THE COASTAL TERMINALS AFTER 21Z. ACTIVITY WILL BE
ISOLATED THUS WILL INDICATE CB/VCSH IN COASTAL TERMINAL TAFS
21Z-00Z.
THUNDERSTORM DEVELOPMENT IS EXPECTED BY 00Z NORTHWEST AND WEST OF
FLO/LBT. THE BEST COVERAGE SHOULD BE NORTHWEST OF LBT. THIS ACTIVITY
WILL MOVE EAST AND COULD AFFECT THE FLO/LBT TERMINALS BY THIS
EVENING. SINCE ACTIVITY IS EXPECTED TO BE ISOLATED WILL ONLY MENTION
CB IN FLO TAF AND CB/VCSH IN LBT TAFS 00Z-06Z. OTHERWISE OVERNIGHT
THERE IS A SLIGHT CHANCE OF IFR VISIBILITIES TO DEVELOP BY 10Z AT
FLO/LBT. DUE TO POSSIBLE BROKEN CLOUD COVER WILL INDICATE MVFR
VISIBILITIES IN TAFS. COASTAL TERMINALS SHOULD REMAIN VFR EXCEPT
SOME TEMPO MVFR VISIBILITIES IN THE PRE-DAWN HOURS ESPECIALLY AT CRE.
TEMPO MVFR CEILINGS EXPECTED FRIDAY MORNING. CEILINGS SHOULD IMPROVE
TO VFR BY MID-MORNING.
EXTENDED OUTLOOK THROUGH MONDAY...ISOLATED THUNDERSTORMS THROUGH
SATURDAY. SCATTERED THUNDERSTORMS SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM THURSDAY...REPLACED SMALL CRAFT ADVISORY WITH EXERCISE
CAUTION HEADLINE AND WILL INCLUDE AN EXERCISE CAUTION FOR ALL WATERS
INTO THIS EVE AND FOR OVERNIGHT FOR AMZ250-252. PRESSURE GRADIENT
DOES NOT CHANGE ALL THAT MUCH...SO WINDS IN 15 TO 20 KT RANGE FROM
THE SW ARE EXPECTED TO PERSIST. SE SWELL 8/9 SECONDS IS STILL
EVIDENT AND IS NOT EXPECTED TO CHANGE THROUGH THE PERIOD. WILL CAP
SEAS AT 5 FT WITH 6 FOOTERS POSSIBLE OUT AROUND FRYING PAN SHOALS.
NEAR SHORE WATERS WILL RANGE FROM 2 TO 4 FT...HIGHEST ACROSS THE
BRUNSWICK NEAR SHORE WATERS.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...HIGH PRESSURE WILL RIDGE BACK INTO LOCAL AREA
THROUGH THE PERIOD MAINTAINING S-SW FLOW. SPEEDS SHOULD REMAIN
AROUND 15 KTS THROUGH FRI...BUT GRADIENT TIGHTENS HEADING INTO SAT
AND EXPECT SW WINDS TO INCREASE TO NEAR 20 KTS BY SAT AFTN. OVERALL
SEAS SHOULD REMAIN 3 TO 4 FT ON FRI...BUT ON SAT WITH INCREASED
FLOW...WOULD EXPECT SEAS TO INCREASE INTO THE 3 TO 6 FT
RANGE...POSSIBLY WARRANTING A SCEC OR SCA.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 3 PM THURSDAY...A STALLED FRONTAL BOUNDARY IS EXPECTED TO BE
DRAPED ALONG THE COAST SUNDAY AND EARLY MONDAY...RESULTING IN A
LOW CONFIDENCE WIND DIRECTION FORECAST. HOWEVER LATER MONDAY...THE
FRONT WILL GET PUSHED OFFSHORE AS HIGH PRESSURE BUILDS IN FROM THE
NW...AND A NORTHERLY COMPONENT WILL BECOME PREDOMINANT BY MONDAY
AFTERNOON.
SCATTERED SHOWERS AND TSTMS WILL BE POSSIBLE IN ASSOCIATION WITH THE
FRONTAL BOUNDARY SUNDAY-SUNDAY NIGHT. COVERAGE IS EXPECTED TO
INCREASE MONDAY AS A SHORTWAVE MOVES ACROSS THE AREA.
A MODEST GRADIENT SHOULD RESULT IN SUSTAINED WINDS 15 KT OR LESS
THROUGH THE PERIOD...HOWEVER AS ALWAYS...GUSTS MAY BE QUITE HIGHER
IN THE VICINITY OF THE EXPECTED CONVECTION.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RGZ
NEAR TERM...RJD
SHORT TERM...RGZ
LONG TERM...CRM
AVIATION...MRR
000
FXUS62 KRAH 071845
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
243 PM EDT THU MAY 7 2009
.SYNOPSIS...
A MOIST AND UNSTABLE AIR MASS COUPLED WITH A SURFACE TROUGH IN THE
VICINITY WILL TRIGGER SCATTERED AFTERNOON AND EVENING THUNDERSTORMS
THROUGH SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 235 PM THURSDAY...
AIR MASS CONTINUES TO DESTABILIZE AS MIXED LAYER CAPE AT 17Z AROUND
1500 J/KG AND SURFACE BASED LIFTED INDICES AROUND MINUS 5/MINUS 6
AND LOW LEVEL LAPSE RATES APPROACHING 8 DEG C/KM. 0-6KM BULK SHEAR
35-40KTS NOT SHABBY WITH WIND PROFILE FAIRLY UNIDIRECTIONAL. THESE
PARAMETERS SUGGEST THAT CELLS SHOULD EVENTUALLY INTO BROKEN LINE.
DAMAGING DOWNBURSTS AND LARGE HAIL APPEAR TO BE THE MAIN SEVERE
WEATHER FACTORS AS O-1KM HELICITY LESS THAN 100 M2/SEC2 AND LCL
HEIGHTS GENERALLY AT OR ABOVE 1000M. AT 1820Z...ALREADY SEEING
ISOLATED CELLS DEVELOP ALONG THE BLUE RIDGE AND ON A NARROW ZONE OF
SURFACE CONFLUENCE FROM LAURINBURG TO GOLDSBORO TO WILSON. EXPECT
THUNDERSTORM COVERAGE TO INCREASE IN COVERAGE AFTER 20-21Z AS MID
LEVEL TROUGH OVER THE LOWER OH-TN VALLEY ADVANCES EAST. WHILE
MAJORITY OF CONVECTION WILL DISSIPATE WITH LOSS OF HEATING...MAY SEE
SCATTERED CONVECTION PERSIST UP TO 04Z IN THE EAST AS THIS REGION
WILL BE IN THE FAVORABLE LEFT EXIT REGION OF 300MB JET OVER THE TN
VALLEY. FOR NOW...WILL GO WITH A SOLID CHANCE POP LATE THIS
AFTERNOON/EARLY EVENING WITH SLIGHT CHANCE POP IN THE EAST BY 04Z.
SKIES WILL BECOME MOSTLY CLEAR IN WAKE OF CONVECTION. MOIST LOW
LEVEL AIR MASS SHOULD ALLOW POCKETS OF FOG AND/OR STRATUS TO DEVELOP
BY DAYBREAK. MINS TONIGHT MAINLY IN THE MID 60S.
&&
.SHORT TERM /FRIDAY/...
AS OF 240 PM THURSDAY...
FRIDAY...CONDITIONALLY UNSTABLE AIR MASS WILL REMAIN ON PLACE BUT
FOCUS FOR CONVECTIVE DEVELOPMENT ASIDE FROM INSOLATION WILL NOT
ARRIVE UNTIL LATE IN THE DAY OR AFTER SUNSET. EXPECT SCATTERED
CONVECTION TO FIRE WITH A FEW STORMS BRIEFLY SEVERE LATE IN THE DAY.
STEADY SW FLOW AND DECENT INSOLATION WILL MAKE IT FEEL LIKE EARLY
SUMMER. LOW LEVEL THICKNESSES TOP OUT NEAR 1410M. PREVIOUS FORECAST
OF MID/UPPER 80S LOOKS ON TARGET.
&&
.LONG TERM TERM /FRIDAY NIGHT THROUGH THURSDAY/...
TO FOLLOW SHORTLY
&&
.AVIATION /17Z THURSDAY THROUGH TUESDAY/...
AS OF 103 PM THURSDAY...
A MOIST AND CONDITIONALLY UNSTABLE AIR MASS WILL REMAIN IN PLACE
ACROSS CENTRAL NC THROUGH THE WEEKEND. THIS WILL RESULT IN MAINLY
VFR CONDITIONS WITH PERIODS OF MVFR/IFR DUE TO SCATTERED CONVECTION
AND EARLY MORNING FOG AND/OR STRATUS.
THROUGH 03Z FRI...A WEAK SURFACE TROUGH WILL EDGE SLOWLY EAST ACROSS
CENTRAL NC. AIR MASS AHEAD OF THIS FEATURE WILL CONTINUE TO
DESTABILIZE DUE TO STRONG HEATING. EXPECT TO SEE SCATTERED
CONVECTION TO POP OVER THE WESTERN PIEDMONT BETWEEN 20-22Z WITH
CONVECTION POSSIBLY FORMING INTO A BROKEN LINE BY 22Z. THIS LINE OF
CONVECTION SHOULD PROGRESS EAST INTO THE SANDHILLS AND COASTAL PLAIN
BY 00Z. WITH LOSS OF HEATING...SHOULD SEE CONVECTION DIMINISH
DISSIPATE BY 04Z.
SKIES SHOULD CLEAR AFTER 04Z. COOLING OF MOIST AIR MASS NEAR THE
SURFACE SHOULD RESULT IN FORMATION OF WIDESPREAD FOG AND/OR STRATUS
BY DAYBREAK FRIDAY. FOG/STRATUS SHOULD BURN OFF BY 13Z FRIDAY.
EXPECT VFR CONDITIONS THROUGH MOST OF FRIDAY. EXPECT ANY CONVECTION
FRIDAY TO HOLD OFF UNTIL LATE IN THE DAY (AFTER 21Z). MAY SEE
CONVECTION PERSIST A BIT LONGER FRIDAY NIGHT AS UPPER LEVEL TROUGH
CROSSES REGION.
THE MOIST AND UNSTABLE AIR MASS WILL PERSIST ACROSS THE REGION
THROUGH EARLY NEXT WEEK. A LINGERING SURFACE BOUNDARY WILL HELP TO
INITIATE SCATTERED CONVECTION EACH AFTERNOON/EVENING. THIS WILL
RESULT IN PERIODS OF MVFR/IFR CONDITIONS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS
SHORT TERM...WSS
LONG TERM...
AVIATION...WSS
000
FXUS62 KMHX 071742
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
141 PM EDT THU MAY 7 2009
.SYNOPSIS...
A FRONT WILL LINGER WEST OVER CENTRAL NC AND WILL DISSIPATE FRIDAY.
ANOTHER FRONT WILL APPROACH THE AREA SATURDAY AND MOVE OFFSHORE
SUNDAY. THIS FRONT WILL LINGER OFFSHORE THROUGH MONDAY. HIGH
PRESSURE WILL BUILD INTO THE AREA TUESDAY AND WILL REMAIN OVER THE
AREA THROUGH THURSDAY. A FRONT WILL APPROACH FROM THE WEST LATE
THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
LN OF STORMS HAS MV OFFSHORE THIS EARLY AFTN. SW LO LVL FLO UNDR
CLRG SKIES. QUESTION IS...HAS THE AMS BEEN WORKED OVR ENUF TO SPPRS
ANY FURTHER ACTVTY THIS AFTN. WK UPR TROF WL MV THRU WI ANTHR S/WV
TNGT. CUD SEE SUM SHWRS LTR TNGT AS THIS ENERGY SWINGS THRU. WL HV
DCRSG CHCS AFT MIDNGT AS TROF EXITS.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
ZNL FLO AT 5H ESTABLISHES ITSELF OVR THE AREA ON FRI. SERIES OF WK
S/WVS WL MV THRU THE FLO INTO THE WKEND. HARD TO KEY ON ANY OF THESE
S/WVS AND TIMING WL BE DIFFICULT TO DETERMINE. GFS/NAM/SREF ALL
FAIRLY DRY IN THE FRI THRU SAT TM PD. HARD TO RULE OUT ANY PCPN IN
THIS TYPE OF PATTERN. WL CARRY SCHC. BEST LUKG S/WV IN MDLS WL BE
FRI AFTN. HI TEMPS WL RMN IN THE 80S FRI AND SAT WI SW LO LVL FLO
CONTG.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
MDLS SHOWG A S/WV MVG THRU THE ZNL FLO WL PUSH A FRNT THRU THE AREA
SAT NGT. FRNT WL BE S OF AREA BY SUN. ANTHR SURGE WL PUSH THRU SUN
AFTN AND NGT. 5H FLO TO BCM MR AMPLIFIED OVR THE ECST MON AND A WV
FRMS ON THE FRNT TO OUR S. CUD SEE SUM OVRRNNG PCPN FRM THIS WV MON
AND MON NGT. HI PRES BOTH AT THE SFC AND ALFT WL BLD IN TUE NGT.
THIS RDG WL MV OFFSHR THU. HI TEMPS IN THE 70S BHND THE FRNT ON MON
WL CLIMB BACK INTO THE LWR 80S BY THU.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
AS OF 1115 AM THURSDAY...WIDESPREAD DEEP/MOIST CONVECTION ASSOCIATED
WITH A PRONOUNCED MID LEVEL DISTURBANCE WILL BE EAST OF THE TAF
SITES BY 16Z WITH PREVAILING VFR CONDITIONS EXPECTED BY 17Z.
ALTHOUGH THE AIRMASS WILL REMAIN WARM/UNSTABLE IN THE WAKE OF THIS
MORNINGS CONVECTION THE UPPER FORCING IS NOT ALL THAT IMPRESSIVE
SO ANY RESULTING ACTIVITY WILL MUCH MORE LOCALIZED.
INSTABILITY/AND SHEAR SUGGEST THAT STORMS THAT FORM THIS
AFTERNOON/EVENING WILL BE ABLE TO PRODUCE GUSTY WINDS...HAIL AND
TORRENTIAL DOWNPOURS
ANOTHER VORT MAX CROSSES THE REGION LATE TONIGHT WHICH COULD
BRING A FEW SHOWERS OR ISOLATED THUNDERSTORMS ACROSS RTES.
WAVES OF LOW PRES CONTINUE TO LIFT NE ALONG A STALLED FRONT TO THE
NW THROUGH THE REMAINDER OF THE WEEK. MAINLY VFR CONDITIONS
EXPECTED THROUGH THE LONG TERM BUT COULD SEE PERIODS OF SHOWERS
AND MAINLY AFTERNOON CONVECTION. A FRONT PUSHES THROUGH THE REGION
SUN BUT ANOTHER WAVE OF LOW PRES WILL CONTINUE TO BRING A CHANCE
OF SHOWERS THROUGH MON.
&&
.MARINE...
AS OF 1115 AM THURSDAY...WINDS ARE EXPECTED TO DECREASE OVER THE
SOUNDS AND NORTHERN WATERS EARLY THIS AFTERNOON AFTER THE PASSAGE
OF A MID LEVEL IMPULSE LESSENS THE GRADIENT. THE ADVISORIES FOR
THE SOUNDS AND NORTHERN WATERS ARE FORECAST TO EXPIRE AT 2 PM AND
4 PM RESPECTIVELY AND THIS SEEMS REASONABLE BASED ON FORECAST WIND
FIELDS FROM THE MODELS. SMALL CRAFT ADVISORY CONDITIONS...MAINLY
FOR SEAS WILL CONTINUE OVER THE THE REMAINDER OF THE COASTAL
WATERS TODAY AND TONIGHT WITH A STEADY S/SW BREEZE AROUND 20 KT
EXPECTED TO PERSIST PRODUCING SEAS 4-7 FT.
PREVIOUS DISCUSSION:MODERATE SOUTHERLY FLOW CONTINUES ACROSS THE
WATERS AS A SURFACE TROUGH APPROACHES THE REGION. WINDS STRONGEST
ACROSS THE SOUNDS AND N OF HATTERAS WHERE 20-25 KT REPORTED AT OB
SITES WHILE 10-15 KT REPORTED ACROSS SRN MOST WATERS. SEAS HAVE
BUILT TO 6 FT AT DIAMOND BUOY BUT 4-5 FT REPORTED AT OTHER BUOYS.
GFS OVERDONE ON WINDS...ESPECIALLY ACROSS CENTRAL AND SOUTHERN
WATERS WHICH HAS ALLOWED WAVEWATCH TO OVERESTIMATE SEAS BY A FOOT
OR TWO. WILL CONTINUE SCA TODAY ACROSS ALL WATERS BUT COULD BE
MINIMAL IN SOME AREAS...MAINLY SRN WATERS...BUT STILL COULD SEE
SEAS TO 6 FT ACROSS OUTER PORTIONS AND DON`T WANT TO DROP
PREMATURELY.
THERE WILL BE LITTLE CHANGE IN THE WX PATTERN THROUGH SAT NIGHT
WITH THE BERMUDA HIGH REMAINING ACROSS THE WRN ATLANTIC AND
SEVERAL SFC TROUGHS OR AREAS OF LOW PRES PASSING NW OF THE WATERS.
MODERATE SLY FLOW EXPECTED TO CONTINUE THROUGH THIS PERIOD AND
SEAS TO 6 FT WILL BE POSSIBLE ACROSS THE OUTER PORTIONS OF THE
WATERS FROM DIAMOND SHOALS S SO WILL MAINTAIN SCA FOR THE PERIOD.
SAT WILL SEE STRONGEST FLOW WITH SCA CONDITIONS LIKELY ACROSS ALL
WATERS AS LOW PRES MOVE ACROSS THE MID ATLANTIC. THE SFC TROUGH
FINALLY BEGINS TO SLOWLY PUSH S INTO THE WATERS SAT NIGHT AND SUN
THEN IS EXPECTED TO PUSH S OF THE WATERS BY MON WITH NLY WINDS
DEVELOPING.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR AMZ130-
135.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT SUNDAY FOR AMZ152-154-156-
158.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR AMZ150.
&&
$$
SYNOPSIS...CGG
NEAR TERM...CGG
SHORT TERM...CGG
LONG TERM...CGG
AVIATION...JME/SK
MARINE...JME/SK
000
FXUS62 KMHX 071741
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
141 AM EDT THU MAY 7 2009
.SYNOPSIS...
A FRONT WILL LINGER WEST OVER CENTRAL NC AND WILL DISSIPATE FRIDAY.
ANOTHER FRONT WILL APPROACH THE AREA SATURDAY AND MOVE OFFSHORE
SUNDAY. THIS FRONT WILL LINGER OFFSHORE THROUGH MONDAY. HIGH
PRESSURE WILL BUILD INTO THE AREA TUESDAY AND WILL REMAIN OVER THE
AREA THROUGH THURSDAY. A FRONT WILL APPROACH FROM THE WEST LATE
THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
LN OF STORMS HAS MV OFFSHORE THIS EARLY AFTN. SW LO LVL FLO UNDR
CLRG SKIES. QUESTION IS...HAS THE AMS BEEN WORKED OVR ENUF TO SPPRS
ANY FURTHER ACTVTY THIS AFTN. WK UPR TROF WL MV THRU WI ANTHR S/WV
TNGT. CUD SEE SUM SHWRS LTR TNGT AS THIS ENERGY SWINGS THRU. WL HV
DCRSG CHCS AFT MIDNGT AS TROF EXITS.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
ZNL FLO AT 5H ESTABLISHES ITSELF OVR THE AREA ON FRI. SERIES OF WK
S/WVS WL MV THRU THE FLO INTO THE WKEND. HARD TO KEY ON ANY OF THESE
S/WVS AND TIMING WL BE DIFFICULT TO DETERMINE. GFS/NAM/SREF ALL
FAIRLY DRY IN THE FRI THRU SAT TM PD. HARD TO RULE OUT ANY PCPN IN
THIS TYPE OF PATTERN. WL CARRY SCHC. BEST LUKG S/WV IN MDLS WL BE
FRI AFTN. HI TEMPS WL RMN IN THE 80S FRI AND SAT WI SW LO LVL FLO
CONTG.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
MDLS SHOWG A S/WV MVG THRU THE ZNL FLO WL PUSH A FRNT THRU THE AREA
SAT NGT. FRNT WL BE S OF AREA BY SUN. ANTHR SURGE WL PUSH THRU SUN
AFTN AND NGT. 5H FLO TO BCM MR AMPLIFIED OVR THE ECST MON AND A WV
FRMS ON THE FRNT TO OUR S. CUD SEE SUM OVRRNNG PCPN FRM THIS WV MON
AND MON NGT. HI PRES BOTH AT THE SFC AND ALFT WL BLD IN TUE NGT.
THIS RDG WL MV OFFSHR THU. HI TEMPS IN THE 70S BHND THE FRNT ON MON
WL CLIMB BACK INTO THE LWR 80S BY THU.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
AS OF 1115 AM THURSDAY...WIDESPREAD DEEP/MOIST CONVECTION ASSOCIATED
WITH A PRONOUNCED MID LEVEL DISTURBANCE WILL BE EAST OF THE TAF
SITES BY 16Z WITH PREVAILING VFR CONDITIONS EXPECTED BY 17Z.
ALTHOUGH THE AIRMASS WILL REMAIN WARM/UNSTABLE IN THE WAKE OF THIS
MORNINGS CONVECTION THE UPPER FORCING IS NOT ALL THAT IMPRESSIVE
SO ANY RESULTING ACTIVITY WILL MUCH MORE LOCALIZED.
INSTABILITY/AND SHEAR SUGGEST THAT STORMS THAT FORM THIS
AFTERNOON/EVENING WILL BE ABLE TO PRODUCE GUSTY WINDS...HAIL AND
TORRENTIAL DOWNPOURS
ANOTHER VORT MAX CROSSES THE REGION LATE TONIGHT WHICH COULD
BRING A FEW SHOWERS OR ISOLATED THUNDERSTORMS ACROSS RTES.
WAVES OF LOW PRES CONTINUE TO LIFT NE ALONG A STALLED FRONT TO THE
NW THROUGH THE REMAINDER OF THE WEEK. MAINLY VFR CONDITIONS
EXPECTED THROUGH THE LONG TERM BUT COULD SEE PERIODS OF SHOWERS
AND MAINLY AFTERNOON CONVECTION. A FRONT PUSHES THROUGH THE REGION
SUN BUT ANOTHER WAVE OF LOW PRES WILL CONTINUE TO BRING A CHANCE
OF SHOWERS THROUGH MON.
&&
.MARINE...
AS OF 1115 AM THURSDAY...WINDS ARE EXPECTED TO DECREASE OVER THE
SOUNDS AND NORTHERN WATERS EARLY THIS AFTERNOON AFTER THE PASSAGE
OF A MID LEVEL IMPULSE LESSENS THE GRADIENT. THE ADVISORIES FOR
THE SOUNDS AND NORTHERN WATERS ARE FORECAST TO EXPIRE AT 2 PM AND
4 PM RESPECTIVELY AND THIS SEEMS REASONABLE BASED ON FORECAST WIND
FIELDS FROM THE MODELS. SMALL CRAFT ADVISORY CONDITIONS...MAINLY
FOR SEAS WILL CONTINUE OVER THE THE REMAINDER OF THE COASTAL
WATERS TODAY AND TONIGHT WITH A STEADY S/SW BREEZE AROUND 20 KT
EXPECTED TO PERSIST PRODUCING SEAS 4-7 FT.
PREVIOUS DISCUSSION:MODERATE SOUTHERLY FLOW CONTINUES ACROSS THE
WATERS AS A SURFACE TROUGH APPROACHES THE REGION. WINDS STRONGEST
ACROSS THE SOUNDS AND N OF HATTERAS WHERE 20-25 KT REPORTED AT OB
SITES WHILE 10-15 KT REPORTED ACROSS SRN MOST WATERS. SEAS HAVE
BUILT TO 6 FT AT DIAMOND BUOY BUT 4-5 FT REPORTED AT OTHER BUOYS.
GFS OVERDONE ON WINDS...ESPECIALLY ACROSS CENTRAL AND SOUTHERN
WATERS WHICH HAS ALLOWED WAVEWATCH TO OVERESTIMATE SEAS BY A FOOT
OR TWO. WILL CONTINUE SCA TODAY ACROSS ALL WATERS BUT COULD BE
MINIMAL IN SOME AREAS...MAINLY SRN WATERS...BUT STILL COULD SEE
SEAS TO 6 FT ACROSS OUTER PORTIONS AND DON`T WANT TO DROP
PREMATURELY.
THERE WILL BE LITTLE CHANGE IN THE WX PATTERN THROUGH SAT NIGHT
WITH THE BERMUDA HIGH REMAINING ACROSS THE WRN ATLANTIC AND
SEVERAL SFC TROUGHS OR AREAS OF LOW PRES PASSING NW OF THE WATERS.
MODERATE SLY FLOW EXPECTED TO CONTINUE THROUGH THIS PERIOD AND
SEAS TO 6 FT WILL BE POSSIBLE ACROSS THE OUTER PORTIONS OF THE
WATERS FROM DIAMOND SHOALS S SO WILL MAINTAIN SCA FOR THE PERIOD.
SAT WILL SEE STRONGEST FLOW WITH SCA CONDITIONS LIKELY ACROSS ALL
WATERS AS LOW PRES MOVE ACROSS THE MID ATLANTIC. THE SFC TROUGH
FINALLY BEGINS TO SLOWLY PUSH S INTO THE WATERS SAT NIGHT AND SUN
THEN IS EXPECTED TO PUSH S OF THE WATERS BY MON WITH NLY WINDS
DEVELOPING.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR AMZ130-
135.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT SUNDAY FOR AMZ152-154-156-
158.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR AMZ150.
&&
$$
SYNOPSIS...CGG
NEAR TERM...CGG
SHORT TERM...CGG
LONG TERM...CGG
AVIATION...JME/SK
MARINE...JME/SK
000
FXUS62 KILM 071725
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
130 PM EDT THU MAY 7 2009
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A SHORTWAVE TROUGH WILL
MOVE EAST OF THE AREA AROUND MIDDAY....LEAVING BEHIND A WEAK TROUGH
OF LOW PRESSURE. WARMER AND DRIER WEATHER WILL PREVAIL ON FRIDAY AND
SATURDAY AS HIGH PRESSURE BUILDS INTO THE REGION. A COLD FRONT WILL
MOVE ACROSS THE AREA SUNDAY AND STALL ON MONDAY BEFORE BRINGING
DRIER AIR FOR THE EARLY PART OF NEXT WEEK...AS HIGH PRESSURE BUILDS
INTO THE REGION FROM THE NORTH THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 10 AM THURSDAY...MID LEVEL SHORTWAVE WILL MOVE OFF THE COAST
THROUGH MIDDAY. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO CLEAR
COAST AREAS BY AROUND NOON. SUBSIDENCE AND DRIER AIR IN THE WAKE OF
THIS FEATURE IS EXPECTED TO KEEP CONVECTION THIS AFTERNOON ISOLATED
TO PERHAPS SCATTERED. IN ORDER FOR STORMS TO REFIRE...AND IN THE
ABSENCE OF ANY NOTABLE TRIGGERS ALOFT...WE ARE GOING TO HAVE TO
RECEIVE SOME GOOD INSOLATION. IT DOES APPEAR THAT WITH DRIER AIR
WORKING IN FROM THE W THAT THIS WILL BE THE CASE. TEMPS SHOULD
RESPOND...REACHING WELL INTO THE 80S. THUNDERSTORMS THIS AFTERNOON
COULD PRODUCE ISOLATED STRONG TO DAMAGING WIND GUSTS. HAIL RISK IS
LOW GIVEN WET BULB ZEROS ABOVE 12KFT.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...FLAT PROGRESSIVE 5H PATTERN REMAINS IN
PLACE THROUGH THE PERIOD AND WILL KEEP STALLED SURFACE BOUNDARY
JUST NORTH OF THE AREA. WEAK SHORTWAVES PASSING NORTH OF THE AREA
MAY NOT BE CLOSE ENOUGH TO HAVE AN IMPACT ON THE AREA. EVEN IF A
WAVE WERE TO MOVE ACROSS THE AREA THERE IS A LOT OF DRY AIR AND A
CAP FROM 900 TO 800 MB THAT WOULD TEND TO SUPPRESS CONVECTION. SEA
BREEZE MIGHT BE ABLE TO PROVIDE ENOUGH LIFT TO OVER COME THE CAP
ON FRI...WHEN CAP IS A LITTLE WEAKER AND THERE IS A LITTLE MORE
MOISTURE AVAILABLE. WILL CARRY LOW CHANCE POP INLAND FRI WITH
SLIGHT CHANCE CLOSER TO THE COAST...WHICH IS PROBABLY ON THE
GENEROUS SIDE.
HOLDING ONTO SLIGHT CHANCE POPS FOR SAT FOR NOW BUT ITS LOOKING LESS
LIKELY. PRECIP HOPES WILL BE TIED TO PVA AHEAD OF SHORTWAVE SAT
NIGHT...AND THE GUIDANCE HAS BEEN FIGHTING FEEDBACK WHICH AFFECTS
TIMING AND STRENGTH OF THESE WAVES. TEMPERATURES WILL RUN 5 TO 10
DEGREES ABOVE CLIMO BOTH DAY AND NIGHT...WITH READINGS A LITTLE
CLOSER TO CLIMO NEARER TO THE COAST.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 3 AM THURSDAY...PROGRESSIVE FLAT 5H PATTERN CONTINUES
THROUGH MUCH OF THE PERIOD. SURFACE BOUNDARY THAT HAS BEEN STALLED
NORTHWEST OF THE AREA WILL START HAVING A DIRECT IMPACT ON THE
AREA LATER SUN AND CONTINUING THROUGH AT LEAST MON NIGHT. 12Z
ECMWF PUSHES THE FRONT SOUTH OF THE AREA TUE AS HIGH PRESSURE
BUILDS IN FROM THE NORTH. THE 00Z GFS IS IN SOMEWHAT GOOD
AGREEMENT WITH THIS TIMING...THOUGH IT SHOULD BE NOTED THAT EVERY
24 HOURS IT SEEMS FROPA IS AGAIN BEING DELAYED.
PRECIP CHANCES WILL MAINLY BE DEPENDANT ON TIMING OF SHORTWAVE
PASSAGE AND OTHER THAN A GENERAL TIME RANGE...SUN NIGHT AND AGAIN
MON AFTN...CANNOT GET TO PRECISE. ALSO EXPECT DIURNALLY DRIVEN
INSTABILITY AND THE SEA BREEZE TO PRODUCE SOME CONVECTION...BUT
COVERAGE WILL REMAIN LIMITED. TEMPERATURES SUN AND MON WILL BE NEAR
CLIMO...MAINLY DUE TO INCREASING CLOUD COVER THOUGH HEIGHTS DO DROP
A BIT ON MON AS SOUTHERN BRANCH OF JET STREAM SAGS SOUTH. IF LATEST
GFS AND 12Z ECMWF ARE TO BE BELIEVED...TUE AND WED WILL BE DRY WITH
TEMPERATURES BELOW CLIMO.
&&
.AVIATION /18Z THURSDAY THROUGH MONDAY/...
TERMINALS ARE CURRENTLY VFR. WINDS ARE SOUTHWEST 10-20 KNOTS. GUSTS
TO 20-25 KNOTS WILL BE POSSIBLE AT THE COASTAL TERMINALS BY MID
AFTERNOON.
EXPECT CB/THUNDERSTORM DEVELOPMENT THIS AFTERNOON SOUTHWEST TO SOUTH
OF MYR NEAR THE OLD SURFACE TROUGH. THIS ACTIVITY COULD ADVECT
NORTHEAST INTO THE COASTAL TERMINALS AFTER 21Z. ACTIVITY WILL BE
ISOLATED THUS WILL INDICATE CB/VCSH IN COASTAL TERMINAL TAFS
21Z-00Z.
THUNDERSTORM DEVELOPMENT IS EXPECTED BY 00Z NORTHWEST AND WEST OF
FLO/LBT. THE BEST COVERAGE SHOULD BE NORTHWEST OF LBT. THIS ACTIVITY
WILL MOVE EAST AND COULD AFFECT THE FLO/LBT TERMINALS BY THIS
EVENING. SINCE ACTIVITY IS EXPECTED TO BE ISOLATED WILL ONLY MENTION
CB IN FLO TAF AND CB/VCSH IN LBT TAFS 00Z-06Z. OTHERWISE OVERNIGHT
THERE IS A SLIGHT CHANCE OF IFR VISIBILITIES TO DEVELOP BY 10Z AT
FLO/LBT. DUE TO POSSIBLE BROKEN CLOUD COVER WILL INDICATE MVFR
VISIBILITIES IN TAFS. COASTAL TERMINALS SHOULD REMAIN VFR EXCEPT
SOME TEMPO MVFR VISIBILITIES IN THE PRE-DAWN HOURS ESPECIALLY AT CRE.
TEMPO MVFR CEILINGS EXPECTED FRIDAY MORNING. CEILINGS SHOULD IMPROVE
TO VFR BY MID-MORNING.
EXTENDED OUTLOOK THROUGH MONDAY...ISOLATED THUNDERSTORMS THROUGH
SATURDAY. SCATTERED THUNDERSTORMS SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 10 AM THURSDAY...STRONG THUNDERSTORMS MOVING ACROSS THE
COASTAL WATERS THROUGH EARLY AFTERNOON WILL CONTINUE TO CHURN UP THE
SEAS AND WILL MAINTAIN SMALL CRAFT ADVISORY AND EXERCISE CAUTION
HEADLINES. SE SWELL AROUND 9 SECONDS IS STILL EVIDENT AND IS NOT
EXPECTED TO CHANGE THROUGH THE PERIOD. WIND DIRECTION WILL REMAIN
FROM THE SSW TO SW THROUGH THE PERIOD.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...SOUTH TO SOUTHWEST FLOW WILL CONTINUE OVER THE
WATERS DURING THE PERIOD. GFS WIND SPEEDS HAVE CONSISTENTLY BEEN TO
HIGH...LIKELY DUE TO AIR/SEA INTERFACE ISSUES...SO FAVORING THE NAM
FOR SPEEDS. ISSUES WITH GFS WIND SPEEDS ALSO CAUSES WWIII GUIDANCE
TO BE ON THE HIGH SIDE. WILL KNOCK ABOUT A FOOT OFF WITH SLIGHT
TWEAKS DUE TO PROLONGED SOUTHERLY FETCH.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 AM THURSDAY...FRONT WILL BE IN THE AREA SUN AND MON MAKING
WIND DIRECTION FORECAST QUITE DIFFICULT. LUCKILY WITH THE FRONT
DRAPED ACROSS THE WATERS GRADIENT WILL BE VERY WEAK AND SPEEDS
WILL BE UNDER 10 KT BUT HIGHLY VARIABLE. EVENTUALLY WINDS WILL
DEVELOP A NORTHERLY COMPONENT BUT THAT MAY NOT OCCUR UNTIL AFTER
THE END OF THE FORECAST PERIOD. LEFT OVER SWELL FROM PROLONGED
PERIOD OF SOUTHERLY FETCH WILL KEEP SEAS RUNNING A LITTLE HIGHER
THAN SPEEDS WOULD SUGGEST. SEAS 3 TO 5 FT ON SUN SUBSIDING TO 2 TO
3 FT FOR MON.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT FRIDAY FOR AMZ250-252.
&&
$$
NEAR TERM...RJD
SHORT TERM...III
LONG TERM...III
AVIATION...MRR
000
FXUS62 KRAH 071715
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
115 PM EDT THU MAY 7 2009
.SYNOPSIS...
A MOIST AND UNSTABLE AIR MASS COUPLED WITH A SURFACE TROUGH IN THE
VICINITY WILL TRIGGER SCATTERED AFTERNOON AND EVENING THUNDERSTORMS
THROUGH SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1108 AM THURSDAY...
BROKEN LINE OF CONVECTION HAS EXITED THE REGION. NVA ALOFT BEHIND
EXITING S/W SHOULD KEEP ATMOSPHERE RELATIVELY QUIET UNTIL 20-21Z.
MOIST AIR MASS WILL BECOME INCREASINGLY UNSTABLE DUE TO INSOLATION.
NEAR TERM MODELS SUGGEST SURFACE BASED CAPES IN VICINITY OF 2500
J/JG WITH MIXED LAYER CAPE AROUND 1500J/KG. PARAMETERS ALOFT ALSO
SUPPORTIVE OF STRONG/SEVERE STORMS AS BULK SHEAR 30-35KTS (THOUGH
NOT AS STRONG AS PAST FEW DAYS) AND LOW LEVEL LAPSE RATES INCREASE
TO 8.5-9 DEG C/KM (AGAIN NOT OVER THE TOP BUT DECENT). MID LEVEL
LAPSE RATES GENERALLY NEAR OR BELOW 6 DEG C/KM. WILL LIKELY SEE
INCREASING DIVERGENCE ALOFT AS H3 JET NOSING SE ACROSS THE CENTRAL
PLAIN INTO THE TN VALLEY...WHICH SHOULD SUPPLY DECENT LIFT ALOFT.
THUS...STILL EXPECT SCATTERED STRONG TO SEVERE STORMS TO ERUPT OVER
CENTRAL NC AFTER 19Z-20Z. MAIN SEVERE WEATHER THREAT WILL BE LARGE
HAIL AND DAMAGING DOWNBURST WINDS. EXPECT CONVECTION TO
WEAKEN/DIMINISH AFTER 00Z WITH LOSS OF HEATING.
DECENT INSOLATION AND STEADY SW FLOW WILL USHER WARMER TEMPS INTO
REGION. THICKNESS ABOUT 10M WARMER THAN WED. HAVE ADJUSTED MAX TEMPS
UP ABOUT 2 DEGREES FROM EARLIER FORECAST.
TONIGHT...CONVECTION SHOULD DISSIPATE BY 03Z. EXPECT CLEAR TO PARTLY
CLOUDY SKIES IN THEIR WAKE. WITH MOIST LOW LEVEL AIR MASS...COULD
SEE AREAS OF FOG DEVELOP AFTER 2 AM. DUE TO HUMID AIR MASS AT THE
SURFACE...EXPECT MIN TEMPS MAINLY IN THE MID 60S.
&&
.SHORT TERM /FRIDAY/...
AS OF 325 AM THURSDAY...
THICKNESSES INCREASE AOA 1410 TO 1415 FRIDAY AFTERNOON SUPPORTING
AFTERNOON HIGHS OF 85 TO 90 ACROSS THE AREA. THE STRONG SURFACE
HEATING WILL SUPPORT A MODERATELY UNSTABLE AIRMASS AS
PIEDMONT SURFACE TROUGH RESIDES IN THE LEE OF THE APPALACHIANS WITH
PWATS INCREASING TO 1.3 TO 1.4". WHILE UPPER JET CORE WILL BE WELL
NORTH OF THE AREA ACROSS OHIO VALLEY AND MID ATLANTIC STATES...S/W
VORTS...POSSIBLY CONVECTIVELY INDUCED IN NATURE IS PROGGED BY BOTH
THE GFS AND NAM TO SPREAD EAST ACROSS THE AREA FRIDAY
AFTERNOON...WITH 40 TO 50KTS OF WEST-NORTHWEST DEEP LAYER SHEAR.
FOR NOW WILL GO WITH SCATTERED...30 TO 40 PERCENT POP WITH A SLIGHT
RISK OF SEVERE STORMS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
AS OF 330 AM THURSDAY...
A DIFFICULT PRECIP FORECAST FOR FRIDAY NIGHT AS IT IS TOUGH TO
ASCERTAIN THE DEVELOPMENT AND EVOLUTION OF ANY MCVS TO OUR WEST THAT
COULD APPROACH THE AREA OVERNIGHT. THE GFS IS THE STRONGEST WITH
SUCH A SHORTWAVE...GENERATING A RATHER ROBUST SFC LOW JUST NORTH OF
THE VA/NC BORDER. THE ECMWF/NAM ARE WEAKER AND FURTHER NORTH WITH
THIS ACTIVITY. IF A MCV DOES TRACK ACROSS THE REGION...IT WOULD
ENCOUNTER ENOUGH LINGERING INSTABILITY (500-800 J/KG MUCAPE) WITH
DEWPOINTS IN THE MID 60S TO PRODUCE SCATTERED CONVECTION. WILL KEEP
POPS ON THE LOW SIDE AND HIGHEST (30%) IN THE FAR NORTH DUE TO THE
UNCERTAINTY. LOWS A VERY MILD AND MUGGY 64-68.
A COLD FRONT WILL BEGIN TO APPROACH FROM THE NORTHWEST BY LATE
SATURDAY AFTERNOON AS A MID LEVEL TROUGH OVER THE GREAT LAKES
BEGINS TO MOVE EAST TOWARD NEW ENGLAND. EXPECT SCATTERED SHOWERS AND
THUNDERSTORMS TO DEVELOP ALONG AND AHEAD OF THE FRONT AS IT
ENCOUNTERS AN UNSTABLE AIRMASS REPRESENTED WITH MLCAPES ABOVE 1000
J/KG. THE BEST MID LEVEL FORCING STAYS WELL TO OUR NORTH...SO WILL
KEEP POPS IN THE CHANCE CATEGORY. THICKNESSES SOAR INTO THE
1410-1420M RANGE...SUPPORTING UPPER 80S TO LOWER 90S FOR HIGHS. THE
FRONT MOVES THROUGH SATURDAY NIGHT WITH A CONTINUED CHANCE FOR
SCATTERED CONVECTION...BUT AS INSTABILITY WANES OVERNIGHT AND THE
LACK OF ANY LARGE SCALE FORCING...PRECIP CHANCES WILL GRADUALLY
DIMINISH. LOWS 60-67.
GUIDANCE IS COMING INTO BETTER AGREEMENT ON STALLING THE COLD FRONT
JUST TO THE SOUTH OF THE CWA SUNDAY AND MONDAY WITH THE 850 MB FRONT
STALLING OVERHEAD. AS SUBTLE PIECES OF ENERGY MOVE THROUGH THE ZONAL
FLOW ALOFT...PERIODS OF OVERRUNNING PRECIPITATION WILL BE POSSIBLE.
RAIN CHANCES LOOK TO TAPER OFF BY TUESDAY MORNING AS A STRONGER
SHORTWAVE OVER THE NORTH CENTRAL STATES DIVES SOUTHEAST INTO THE MID
ATLANTIC AND PUSHES THE FRONT FURTHER SOUTH AND EAST. TEMPS THROUGH
THIS PERIOD WILL RETURN TO MORE SEASONABLE LEVELS...DUE TO THE
COMBINATION OF COOL HIGH PRESSURE BUILDING IN ALONG WITH INCREASED
CLOUD COVER PARTICULARLY ON SUNDAY/MONDAY. HIGHS GENERALLY IN THE
70S AND LOWS IN THE 50S.
&&
.AVIATION /17Z THURSDAY THROUGH TUESDAY/...
AS OF 103 PM THURSDAY...
A MOIST AND CONDITIONALLY UNSTABLE AIR MASS WILL REMAIN IN PLACE
ACROSS CENTRAL NC THROUGH THE WEEKEND. THIS WILL RESULT IN MAINLY
VFR CONDITIONS WITH PERIODS OF MVFR/IFR DUE TO SCATTERED CONVECTION
AND EARLY MORNING FOG AND/OR STRATUS.
THROUGH 03Z FRI...A WEAK SURFACE TROUGH WILL EDGE SLOWLY EAST ACROSS
CENTRAL NC. AIR MASS AHEAD OF THIS FEATURE WILL CONTINUE TO
DESTABILIZE DUE TO STRONG HEATING. EXPECT TO SEE SCATTERED
CONVECTION TO POP OVER THE WESTERN PIEDMONT BETWEEN 20-22Z WITH
CONVECTION POSSIBLY FORMING INTO A BROKEN LINE BY 22Z. THIS LINE OF
CONVECTION SHOULD PROGRESS EAST INTO THE SANDHILLS AND COASTAL PLAIN
BY 00Z. WITH LOSS OF HEATING...SHOULD SEE CONVECTION DIMINISH
DISSIPATE BY 04Z.
SKIES SHOULD CLEAR AFTER 04Z. COOLING OF MOIST AIR MASS NEAR THE
SURFACE SHOULD RESULT IN FORMATION OF WIDESPREAD FOG AND/OR STRATUS
BY DAYBREAK FRIDAY. FOG/STRATUS SHOULD BURN OFF BY 13Z FRIDAY.
EXPECT VFR CONDITIONS THROUGH MOST OF FRIDAY. EXPECT ANY CONVECTION
FRIDAY TO HOLD OFF UNTIL LATE IN THE DAY (AFTER 21Z). MAY SEE
CONVECTION PERSIST A BIT LONGER FRIDAY NIGHT AS UPPER LEVEL TROUGH
CROSSES REGION.
THE MOIST AND UNSTABLE AIR MASS WILL PERSIST ACROSS THE REGION
THROUGH EARLY NEXT WEEK. A LINGERING SURFACE BOUNDARY WILL HELP TO
INITIATE SCATTERED CONVECTION EACH AFTERNOON/EVENING. THIS WILL
RESULT IN PERIODS OF MVFR/IFR CONDITIONS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS
SHORT TERM...CBL
LONG TERM...JFB
AVIATION...WSS
000
FXUS62 KRAH 071524
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1124 AM EDT THU MAY 7 2009
.SYNOPSIS...
A MOIST AND UNSTABLE AIR MASS COUPLED WITH A SURFACE TROUGH IN THE
VICINITY WILL TRIGGER SCATTERED AFTERNOON AND EVENING THUNDERSTORMS
THROUGH SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1108 AM THURSDAY...
BROKEN LINE OF CONVECTION HAS EXITED THE REGION. NVA ALOFT BEHIND
EXITING S/W SHOULD KEEP ATMOSPHERE RELATIVELY QUIET UNTIL 20-21Z.
MOIST AIR MASS WILL BECOME INCREASINGLY UNSTABLE DUE TO INSOLATION.
NEAR TERM MODELS SUGGEST SURFACE BASED CAPES IN VICINITY OF 2500
J/JG WITH MIXED LAYER CAPE AROUND 1500J/KG. PARAMETERS ALOFT ALSO
SUPPORTIVE OF STRONG/SEVERE STORMS AS BULK SHEAR 30-35KTS (THOUGH
NOT AS STRONG AS PAST FEW DAYS) AND LOW LEVEL LAPSE RATES INCREASE
TO 8.5-9 DEG C/KM (AGAIN NOT OVER THE TOP BUT DECENT). MID LEVEL
LAPSE RATES GENERALLY NEAR OR BELOW 6 DEG C/KM. WILL LIKELY SEE
INCREASING DIVERGENCE ALOFT AS H3 JET NOSING SE ACROSS THE CENTRAL
PLAIN INTO THE TN VALLEY...WHICH SHOULD SUPPLY DECENT LIFT ALOFT.
THUS...STILL EXPECT SCATTERED STRONG TO SEVERE STORMS TO ERUPT OVER
CENTRAL NC AFTER 19Z-20Z. MAIN SEVERE WEATHER THREAT WILL BE LARGE
HAIL AND DAMAGING DOWNBURST WINDS. EXPECT CONVECTION TO
WEAKEN/DIMINISH AFTER 00Z WITH LOSS OF HEATING.
DECENT INSOLATION AND STEADY SW FLOW WILL USHER WARMER TEMPS INTO
REGION. THICKNESS ABOUT 10M WARMER THAN WED. HAVE ADJUSTED MAX TEMPS
UP ABOUT 2 DEGREES FROM EARLIER FORECAST.
TONIGHT...CONVECTION SHOULD DISSIPATE BY 03Z. EXPECT CLEAR TO PARTLY
CLOUDY SKIES IN THEIR WAKE. WITH MOIST LOW LEVEL AIR MASS...COULD
SEE AREAS OF FOG DEVELOP AFTER 2 AM. DUE TO HUMID AIR MASS AT THE
SURFACE...EXPECT MIN TEMPS MAINLY IN THE MID 60S.
&&
.SHORT TERM /FRIDAY/...
AS OF 325 AM THURSDAY...
THICKNESSES INCREASE AOA 1410 TO 1415 FRIDAY AFTERNOON SUPPORTING
AFTERNOON HIGHS OF 85 TO 90 ACROSS THE AREA. THE STRONG SURFACE
HEATING WILL SUPPORT A MODERATELY UNSTABLE AIRMASS AS
PIEDMONT SURFACE TROUGH RESIDES IN THE LEE OF THE APPALACHIANS WITH
PWATS INCREASING TO 1.3 TO 1.4". WHILE UPPER JET CORE WILL BE WELL
NORTH OF THE AREA ACROSS OHIO VALLEY AND MID ATLANTIC STATES...S/W
VORTS...POSSIBLY CONVECTIVELY INDUCED IN NATURE IS PROGGED BY BOTH
THE GFS AND NAM TO SPREAD EAST ACROSS THE AREA FRIDAY
AFTERNOON...WITH 40 TO 50KTS OF WEST-NORTHWEST DEEP LAYER SHEAR.
FOR NOW WILL GO WITH SCATTERED...30 TO 40 PERCENT POP WITH A SLIGHT
RISK OF SEVERE STORMS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
AS OF 330 AM THURSDAY...
A DIFFICULT PRECIP FORECAST FOR FRIDAY NIGHT AS IT IS TOUGH TO
ASCERTAIN THE DEVELOPMENT AND EVOLUTION OF ANY MCVS TO OUR WEST THAT
COULD APPROACH THE AREA OVERNIGHT. THE GFS IS THE STRONGEST WITH
SUCH A SHORTWAVE...GENERATING A RATHER ROBUST SFC LOW JUST NORTH OF
THE VA/NC BORDER. THE ECMWF/NAM ARE WEAKER AND FURTHER NORTH WITH
THIS ACTIVITY. IF A MCV DOES TRACK ACROSS THE REGION...IT WOULD
ENCOUNTER ENOUGH LINGERING INSTABILITY (500-800 J/KG MUCAPE) WITH
DEWPOINTS IN THE MID 60S TO PRODUCE SCATTERED CONVECTION. WILL KEEP
POPS ON THE LOW SIDE AND HIGHEST (30%) IN THE FAR NORTH DUE TO THE
UNCERTAINTY. LOWS A VERY MILD AND MUGGY 64-68.
A COLD FRONT WILL BEGIN TO APPROACH FROM THE NORTHWEST BY LATE
SATURDAY AFTERNOON AS A MID LEVEL TROUGH OVER THE GREAT LAKES
BEGINS TO MOVE EAST TOWARD NEW ENGLAND. EXPECT SCATTERED SHOWERS AND
THUNDERSTORMS TO DEVELOP ALONG AND AHEAD OF THE FRONT AS IT
ENCOUNTERS AN UNSTABLE AIRMASS REPRESENTED WITH MLCAPES ABOVE 1000
J/KG. THE BEST MID LEVEL FORCING STAYS WELL TO OUR NORTH...SO WILL
KEEP POPS IN THE CHANCE CATEGORY. THICKNESSES SOAR INTO THE
1410-1420M RANGE...SUPPORTING UPPER 80S TO LOWER 90S FOR HIGHS. THE
FRONT MOVES THROUGH SATURDAY NIGHT WITH A CONTINUED CHANCE FOR
SCATTERED CONVECTION...BUT AS INSTABILITY WANES OVERNIGHT AND THE
LACK OF ANY LARGE SCALE FORCING...PRECIP CHANCES WILL GRADUALLY
DIMINISH. LOWS 60-67.
GUIDANCE IS COMING INTO BETTER AGREEMENT ON STALLING THE COLD FRONT
JUST TO THE SOUTH OF THE CWA SUNDAY AND MONDAY WITH THE 850 MB FRONT
STALLING OVERHEAD. AS SUBTLE PIECES OF ENERGY MOVE THROUGH THE ZONAL
FLOW ALOFT...PERIODS OF OVERRUNNING PRECIPITATION WILL BE POSSIBLE.
RAIN CHANCES LOOK TO TAPER OFF BY TUESDAY MORNING AS A STRONGER
SHORTWAVE OVER THE NORTH CENTRAL STATES DIVES SOUTHEAST INTO THE MID
ATLANTIC AND PUSHES THE FRONT FURTHER SOUTH AND EAST. TEMPS THROUGH
THIS PERIOD WILL RETURN TO MORE SEASONABLE LEVELS...DUE TO THE
COMBINATION OF COOL HIGH PRESSURE BUILDING IN ALONG WITH INCREASED
CLOUD COVER PARTICULARLY ON SUNDAY/MONDAY. HIGHS GENERALLY IN THE
70S AND LOWS IN THE 50S.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 720 AM THURSDAY...
WIDESPREAD SHOWERS WITH SCATTERED THUNDERSTORMS...ASSOCIATED WITH A
STRONG UPPER LEVEL SHORTWAVE TROUGH...WILL CONTINUE TO PUSH WEST TO
EAST ACROSS THE FORECAST AREA...BRINGING A 2 TO 3 HOUR PERIOD OF
MVFR CONDITIONS...ESPECIALLY FROM RDU EAST. THE THUNDER REMAINS
CONFINED ACROSS THE SANDHILLS AND COASTAL PLAIN ALONG THE
INSTABILITY AXIS. THESE STORMS LOOK TO EXIT EAST OF THE AREA BY 15
TO 16Z.
CEILINGS SHOULD SCATTER OUT TO VFR BY LATE MORNING...AND THEN BECOME
BROKEN AGAIN AS STRONG AFTERNOON HEATING WILL ALLOW FOR CONVECTION
TO DEVELOP ALONG A WEAK SURFACE TROUGH LOCATED ACROSS THE WESTERN
PIEDMONT. LOSS OF DAYTIME HEATING SHOULD GREATLY DIMINISH CONVECTIVE
ACTIVITY WITH SCATTERED VFR CEILINGS OVERNIGHT.
UNSETTLED WEATHER EXPECTED FRIDAY NIGHT THROUGH MONDAY AS A COLD
FRONT APPROACHES THEN STALLS IN OUR VICINITY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS
SHORT TERM...CBL
LONG TERM...JFB
AVIATION...CBL
000
FXUS62 KMHX 071515
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
1115 AM EDT THU MAY 7 2009
.SYNOPSIS...
HIGH PRESSURE WILL BE CENTERED IN THE WESTERN ATLANTIC THROUGH
SATURDAY. MEANWHILE A COLD FRONT EAST OF THE APPALACHIANS WILL
MOVE SLOWLY SOUTHEAST TODAY THEN DISSIPATE JUST NORTHWEST OF THE
AREA TONIGHT. A SECONDARY COLD FRONT WILL APPROACH FROM THE
NORTHWEST ON SATURDAY AND MOVE SLOWLY THROUGH THE AREA SATURDAY
NIGHT THROUGH SUNDAY. HIGH PRESSURE GRADUALLY BUILDS INTO THE AREA
FROM THE NORTH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
LN OF SHWRS MVG THRU CSTL SXNS OF CWA ATTM. ARW SHWG PCPN HANGG UP
ALNG CST THIS AFTN...BUT ONLY LMTD UPR LVL SPPRT. RUC13 AND NAM BOTH
SHOWG WKR ENERGY. XPCT ANTHR BATCH OF CONVECTION LTR THIS AFTN AS
MAIN S/WV SWINGS THRU. SHUD HV A BRIEF LULL AFT THIS BATCH MVS
OFFSHR EARLY AFTN BEFORE NXT SET OF SHWRS.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
RELATIVELY BENIGN WEATHER STARTS OUT THIS FCST PERIOD WITH ONLY
WEAK PERTURBATIONS IN THE FLAT MID LVL FLOW TO GENERATE ORGANIZED
CONVECTION. COULD STILL SEE ISOLD/SCTD CONVECTION FIRING ON ANY
LOCALIZED BNDRYS MAINLY DURING PEAK HEAT CYCLES. AN INCREASED CHC
OF SCTD CONVECTION AS A BETTER DEFINED SHORT WAVE TROF APPROACHES
SAT AFTN.
HIGH TEMPS THIS FCST PERIOD WELL INTO THE 80S AND MAY APPROACH
90F INLAND GIVEN THE INCREASED SUNSHINE...LOW LVL THICKNESS
VALUES AND DOWNSLOPE FLOW.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
FRNT WL BE S OF AREA BY SUN. ANTHR SURGE WL PUSH THRU SUN AFTN AND
NGT. 5H FLO TO BCM MR AMPLIFIED OVR THE ECST MON AND A WV FRMS ON
THE FRNT TO OUR S. CUD SEE SUM OVRRNNG PCPN FRM THIS WV MON AND MON
NGT. HI PRES BOTH AT THE SFC AND ALFT WL BLD IN TUE NGT. THIS RDG WL
MV OFFSHR THU. HI TEMPS IN THE 70S BHND THE FRNT ON MON WL CLIMB
BACK INTO THE LWR 80S BY THU.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
AS OF 1115 AM THURSDAY...WIDESPREAD DEEP/MOIST CONVECTION ASSOCIATED
WITH A PRONOUNCED MID LEVEL DISTURBANCE WILL BE EAST OF THE TAF
SITES BY 16Z WITH PREVAILING VFR CONDITIONS EXPECTED BY 17Z.
ALTHOUGH THE AIRMASS WILL REMAIN WARM/UNSTABLE IN THE WAKE OF THIS
MORNINGS CONVECTION THE UPPER FORCING IS NOT ALL THAT IMPRESSIVE
SO ANY RESULTING ACTIVITY WILL MUCH MORE LOCALIZED.
INSTABILITY/AND SHEAR SUGGEST THAT STORMS THAT FORM THIS
AFTERNOON/EVENING WILL BE ABLE TO PRODUCE GUSTY WINDS...HAIL AND
TORRENTIAL DOWNPOURS
ANOTHER VORT MAX CROSSES THE REGION LATE TONIGHT WHICH COULD
BRING A FEW SHOWERS OR ISOLATED THUNDERSTORMS ACROSS RTES.
WAVES OF LOW PRES CONTINUE TO LIFT NE ALONG A STALLED FRONT TO THE
NW THROUGH THE REMAINDER OF THE WEEK. MAINLY VFR CONDITIONS
EXPECTED THROUGH THE LONG TERM BUT COULD SEE PERIODS OF SHOWERS
AND MAINLY AFTERNOON CONVECTION. A FRONT PUSHES THROUGH THE REGION
SUN BUT ANOTHER WAVE OF LOW PRES WILL CONTINUE TO BRING A CHANCE
OF SHOWERS THROUGH MON.
&&
.MARINE...
AS OF 1115 AM THURSDAY...WINDS ARE EXPECTED TO DECREASE OVER THE
SOUNDS AND NORTHERN WATERS EARLY THIS AFTERNOON AFTER THE PASSAGE
OF A MID LEVEL IMPULSE LESSENS THE GRADIENT. THE ADVISORIES FOR
THE SOUNDS AND NORTHERN WATERS ARE FORECAST TO EXPIRE AT 2 PM AND
4 PM RESPECTIVELY AND THIS SEEMS REASONABLE BASED ON FORECAST WIND
FIELDS FROM THE MODELS. SMALL CRAFT ADVISORY CONDITIONS...MAINLY
FOR SEAS WILL CONTINUE OVER THE THE REMAINDER OF THE COASTAL
WATERS TODAY AND TONIGHT WITH A STEADY S/SW BREEZE AROUND 20 KT
EXPECTED TO PERSIST PRODUCING SEAS 4-7 FT.
PREVIOUS DISCUSSION:MODERATE SOUTHERLY FLOW CONTINUES ACROSS THE
WATERS AS A SURFACE TROUGH APPROACHES THE REGION. WINDS STRONGEST
ACROSS THE SOUNDS AND N OF HATTERAS WHERE 20-25 KT REPORTED AT OB
SITES WHILE 10-15 KT REPORTED ACROSS SRN MOST WATERS. SEAS HAVE
BUILT TO 6 FT AT DIAMOND BUOY BUT 4-5 FT REPORTED AT OTHER BUOYS.
GFS OVERDONE ON WINDS...ESPECIALLY ACROSS CENTRAL AND SOUTHERN
WATERS WHICH HAS ALLOWED WAVEWATCH TO OVERESTIMATE SEAS BY A FOOT
OR TWO. WILL CONTINUE SCA TODAY ACROSS ALL WATERS BUT COULD BE
MINIMAL IN SOME AREAS...MAINLY SRN WATERS...BUT STILL COULD SEE
SEAS TO 6 FT ACROSS OUTER PORTIONS AND DON`T WANT TO DROP
PREMATURELY.
THERE WILL BE LITTLE CHANGE IN THE WX PATTERN THROUGH SAT NIGHT
WITH THE BERMUDA HIGH REMAINING ACROSS THE WRN ATLANTIC AND
SEVERAL SFC TROUGHS OR AREAS OF LOW PRES PASSING NW OF THE WATERS.
MODERATE SLY FLOW EXPECTED TO CONTINUE THROUGH THIS PERIOD AND
SEAS TO 6 FT WILL BE POSSIBLE ACROSS THE OUTER PORTIONS OF THE
WATERS FROM DIAMOND SHOALS S SO WILL MAINTAIN SCA FOR THE PERIOD.
SAT WILL SEE STRONGEST FLOW WITH SCA CONDITIONS LIKELY ACROSS ALL
WATERS AS LOW PRES MOVE ACROSS THE MID ATLANTIC. THE SFC TROUGH
FINALLY BEGINS TO SLOWLY PUSH S INTO THE WATERS SAT NIGHT AND SUN
THEN IS EXPECTED TO PUSH S OF THE WATERS BY MON WITH NLY WINDS
DEVELOPING.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR AMZ130-
135.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT SUNDAY FOR AMZ152-154-156-
158.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR AMZ150.
&&
$$
SYNOPSIS...BTC
NEAR TERM...CGG
SHORT TERM...BTC
LONG TERM...CGG
AVIATION...JME/SK
MARINE...JME/SK
000
FXUS62 KMHX 071445
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
1045 AM EDT THU MAY 7 2009
.SYNOPSIS...
HIGH PRESSURE WILL BE CENTERED IN THE WESTERN ATLANTIC THROUGH
SATURDAY. MEANWHILE A COLD FRONT EAST OF THE APPALACHIANS WILL
MOVE SLOWLY SOUTHEAST TODAY THEN DISSIPATE JUST NORTHWEST OF THE
AREA TONIGHT. A SECONDARY COLD FRONT WILL APPROACH FROM THE
NORTHWEST ON SATURDAY AND MOVE SLOWLY THROUGH THE AREA SATURDAY
NIGHT THROUGH SUNDAY. HIGH PRESSURE GRADUALLY BUILDS INTO THE AREA
FROM THE NORTH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
LN OF SHWRS MVG THRU CSTL SXNS OF CWA ATTM. ARW SHWG PCPN HANGG UP
ALNG CST THIS AFTN...BUT ONLY LMTD UPR LVL SPPRT. RUC13 AND NAM BOTH
SHOWG WKR ENERGY. XPCT ANTHR BATCH OF CONVECTION LTR THIS AFTN AS
MAIN S/WV SWINGS THRU. SHUD HV A BRIEF LULL AFT THIS BATCH MVS
OFFSHR EARLY AFTN BEFORE NXT SET OF SHWRS.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
RELATIVELY BENIGN WEATHER STARTS OUT THIS FCST PERIOD WITH ONLY
WEAK PERTURBATIONS IN THE FLAT MID LVL FLOW TO GENERATE ORGANIZED
CONVECTION. COULD STILL SEE ISOLD/SCTD CONVECTION FIRING ON ANY
LOCALIZED BNDRYS MAINLY DURING PEAK HEAT CYCLES. AN INCREASED CHC
OF SCTD CONVECTION AS A BETTER DEFINED SHORT WAVE TROF APPROACHES
SAT AFTN.
HIGH TEMPS THIS FCST PERIOD WELL INTO THE 80S AND MAY APPROACH
90F INLAND GIVEN THE INCREASED SUNSHINE...LOW LVL THICKNESS
VALUES AND DOWNSLOPE FLOW.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
FRNT WL BE S OF AREA BY SUN. ANTHR SURGE WL PUSH THRU SUN AFTN AND
NGT. 5H FLO TO BCM MR AMPLIFIED OVR THE ECST MON AND A WV FRMS ON
THE FRNT TO OUR S. CUD SEE SUM OVRRNNG PCPN FRM THIS WV MON AND MON
NGT. HI PRES BOTH AT THE SFC AND ALFT WL BLD IN TUE NGT. THIS RDG WL
MV OFFSHR THU. HI TEMPS IN THE 70S BHND THE FRNT ON MON WL CLIMB
BACK INTO THE LWR 80S BY THU.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
VFR ACROSS MOST OF RTES EARLY THIS MORNING...HOWEVER PATCHY STCU
BRINGING PERIODS OF MVFR CIGS AT A COUPLE OF THE TERMINALS
INCLUDING OAJ. A ROBUST SHORTWAVE AND SFC TROUGH APPROACHING THE
REGION EARLY THIS MORNING AND EXPECT SHOWERS AND TSTMS TO BEGIN TO
MOVE INTO RTES AFTER 10Z BRINGING AREAS OF MVFR TO LOCALLY IFR
CONDITIONS IN HEAVIEST SHOWERS. GREATEST COVERAGE OF SHOWERS
EXPECTED THROUGH THE MORNING HOURS AS THE VORT MAX CROSSES THE
REGION BUT PLENTY OF INSTABILITY AND MOISTURE REMAINS THIS
AFTERNOON FOR CONTINUED CONVECTION. ANOTHER VORT MAX CROSSES THE
REGION LATE TONIGHT WHICH COULD BRING A FEW SHOWERS OR ISOLATED
THUNDERSTORMS ACROSS RTES.
WAVES OF LOW PRES CONTINUE TO LIFT NE ALONG A STALLED FRONT TO THE
NW THROUGH THE REMAINDER OF THE WEEK. MAINLY VFR CONDITIONS
EXPECTED THROUGH THE LONG TERM BUT COULD SEE PERIODS OF SHOWERS
AND MAINLY AFTERNOON CONVECTION. A FRONT PUSHES THROUGH THE REGION
SUN BUT ANOTHER WAVE OF LOW PRES WILL CONTINUE TO BRING A CHANCE
OF SHOWERS THROUGH MON.
&&
.MARINE...
MODERATE SOUTHERLY FLOW CONTINUES ACROSS THE WATERS AS A SURFACE
TROUGH APPROACHES THE REGION. WINDS STRONGEST ACROSS THE SOUNDS
AND N OF HATTERAS WHERE 20-25 KT REPORTED AT OB SITES WHILE 10-15
KT REPORTED ACROSS SRN MOST WATERS. SEAS HAVE BUILT TO 6 FT AT
DIAMOND BUOY BUT 4-5 FT REPORTED AT OTHER BUOYS. GFS OVERDONE ON
WINDS...ESPECIALLY ACROSS CENTRAL AND SOUTHERN WATERS WHICH HAS
ALLOWED WAVEWATCH TO OVERESTIMATE SEAS BY A FOOT OR TWO. WILL
CONTINUE SCA TODAY ACROSS ALL WATERS BUT COULD BE MINIMAL IN SOME
AREAS...MAINLY SRN WATERS...BUT STILL COULD SEE SEAS TO 6 FT
ACROSS OUTER PORTIONS AND DON`T WANT TO DROP PREMATURELY.
THERE WILL BE LITTLE CHANGE IN THE WX PATTERN THROUGH SAT NIGHT
WITH THE BERMUDA HIGH REMAINING ACROSS THE WRN ATLANTIC AND
SEVERAL SFC TROUGHS OR AREAS OF LOW PRES PASSING NW OF THE WATERS.
MODERATE SLY FLOW EXPECTED TO CONTINUE THROUGH THIS PERIOD AND
SEAS TO 6 FT WILL BE POSSIBLE ACROSS THE OUTER PORTIONS OF THE
WATERS FROM DIAMOND SHOALS S SO WILL MAINTAIN SCA FOR THE PERIOD.
SAT WILL SEE STRONGEST FLOW WITH SCA CONDITIONS LIKELY ACROSS ALL
WATERS AS LOW PRES MOVE ACROSS THE MID ATLANTIC. THE SFC TROUGH
FINALLY BEGINS TO SLOWLY PUSH S INTO THE WATERS SAT NIGHT AND SUN
THEN IS EXPECTED TO PUSH S OF THE WATERS BY MON WITH NLY WINDS
DEVELOPING.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR AMZ130-
135.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT SUNDAY FOR AMZ152-154-156-
158.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR AMZ150.
&&
$$
SYNOPSIS...BTC
NEAR TERM...CGG
SHORT TERM...BTC
LONG TERM...CGG
AVIATION...SK
MARINE...SK
000
FXUS62 KMHX 071442
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
1045 AM EDT THU MAY 7 2009
.SYNOPSIS...
HIGH PRESSURE WILL BE CENTERED IN THE WESTERN ATLANTIC THROUGH
SATURDAY. MEANWHILE A COLD FRONT EAST OF THE APPALACHIANS WILL
MOVE SLOWLY SOUTHEAST TODAY THEN DISSIPATE JUST NORTHWEST OF THE
AREA TONIGHT. A SECONDARY COLD FRONT WILL APPROACH FROM THE
NORTHWEST ON SATURDAY AND MOVE SLOWLY THROUGH THE AREA SATURDAY
NIGHT THROUGH SUNDAY. HIGH PRESSURE GRADUALLY BUILDS INTO THE AREA
FROM THE NORTH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
LN OF SHWRS MVG THRU CSTL SXNS OF CWA ATTM. ARW SHWG PCPN HANGG UP
ALNG CST THIS AFTN...BUT ONLY LMTD UPR LVL SPPRT. RUC13 AND NAM BOTH
SHOWG WKR ENERGY. XPCT ANTHR BATCH OF CONVECTION LTR THIS AFTN AS
MAIN S/WV SWINGS THRU. SHUD HV A BRIEF LULL AFT THIS BATCH MVS
OFFSHR EARLY AFTN BEFORE NXT SET OF SHWRS.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
RELATIVELY BENIGN WEATHER STARTS OUT THIS FCST PERIOD WITH ONLY
WEAK PERTURBATIONS IN THE FLAT MID LVL FLOW TO GENERATE ORGANIZED
CONVECTION. COULD STILL SEE ISOLD/SCTD CONVECTION FIRING ON ANY
LOCALIZED BNDRYS MAINLY DURING PEAK HEAT CYCLES. AN INCREASED CHC
OF SCTD CONVECTION AS A BETTER DEFINED SHORT WAVE TROF APPROACHES
SAT AFTN.
HIGH TEMPS THIS FCST PERIOD WELL INTO THE 80S AND MAY APPROACH
90F INLAND GIVEN THE INCREASED SUNSHINE...LOW LVL THICKNESS
VALUES AND DOWNSLOPE FLOW.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
FRNT WL BE S OF AREA BY SUN. ANTHR SURGE WL PUSH THRU SUN AFTN AND
NGT. 5H FLO TO BCM MR AMPLIFIED OVR THE ECST MON AND A WV FRMS ON
THE FRNT TO OUR S. CUD SEE SUM OVRRNNG PCPN FRM THIS WV MON AND MON
NGT. HI PRES BOTH AT THE SFC AND ALFT WL BLD IN TUE NGT. THIS RDG WL
MV OFFSHR THU.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
VFR ACROSS MOST OF RTES EARLY THIS MORNING...HOWEVER PATCHY STCU
BRINGING PERIODS OF MVFR CIGS AT A COUPLE OF THE TERMINALS
INCLUDING OAJ. A ROBUST SHORTWAVE AND SFC TROUGH APPROACHING THE
REGION EARLY THIS MORNING AND EXPECT SHOWERS AND TSTMS TO BEGIN TO
MOVE INTO RTES AFTER 10Z BRINGING AREAS OF MVFR TO LOCALLY IFR
CONDITIONS IN HEAVIEST SHOWERS. GREATEST COVERAGE OF SHOWERS
EXPECTED THROUGH THE MORNING HOURS AS THE VORT MAX CROSSES THE
REGION BUT PLENTY OF INSTABILITY AND MOISTURE REMAINS THIS
AFTERNOON FOR CONTINUED CONVECTION. ANOTHER VORT MAX CROSSES THE
REGION LATE TONIGHT WHICH COULD BRING A FEW SHOWERS OR ISOLATED
THUNDERSTORMS ACROSS RTES.
WAVES OF LOW PRES CONTINUE TO LIFT NE ALONG A STALLED FRONT TO THE
NW THROUGH THE REMAINDER OF THE WEEK. MAINLY VFR CONDITIONS
EXPECTED THROUGH THE LONG TERM BUT COULD SEE PERIODS OF SHOWERS
AND MAINLY AFTERNOON CONVECTION. A FRONT PUSHES THROUGH THE REGION
SUN BUT ANOTHER WAVE OF LOW PRES WILL CONTINUE TO BRING A CHANCE
OF SHOWERS THROUGH MON.
&&
.MARINE...
MODERATE SOUTHERLY FLOW CONTINUES ACROSS THE WATERS AS A SURFACE
TROUGH APPROACHES THE REGION. WINDS STRONGEST ACROSS THE SOUNDS
AND N OF HATTERAS WHERE 20-25 KT REPORTED AT OB SITES WHILE 10-15
KT REPORTED ACROSS SRN MOST WATERS. SEAS HAVE BUILT TO 6 FT AT
DIAMOND BUOY BUT 4-5 FT REPORTED AT OTHER BUOYS. GFS OVERDONE ON
WINDS...ESPECIALLY ACROSS CENTRAL AND SOUTHERN WATERS WHICH HAS
ALLOWED WAVEWATCH TO OVERESTIMATE SEAS BY A FOOT OR TWO. WILL
CONTINUE SCA TODAY ACROSS ALL WATERS BUT COULD BE MINIMAL IN SOME
AREAS...MAINLY SRN WATERS...BUT STILL COULD SEE SEAS TO 6 FT
ACROSS OUTER PORTIONS AND DON`T WANT TO DROP PREMATURELY.
THERE WILL BE LITTLE CHANGE IN THE WX PATTERN THROUGH SAT NIGHT
WITH THE BERMUDA HIGH REMAINING ACROSS THE WRN ATLANTIC AND
SEVERAL SFC TROUGHS OR AREAS OF LOW PRES PASSING NW OF THE WATERS.
MODERATE SLY FLOW EXPECTED TO CONTINUE THROUGH THIS PERIOD AND
SEAS TO 6 FT WILL BE POSSIBLE ACROSS THE OUTER PORTIONS OF THE
WATERS FROM DIAMOND SHOALS S SO WILL MAINTAIN SCA FOR THE PERIOD.
SAT WILL SEE STRONGEST FLOW WITH SCA CONDITIONS LIKELY ACROSS ALL
WATERS AS LOW PRES MOVE ACROSS THE MID ATLANTIC. THE SFC TROUGH
FINALLY BEGINS TO SLOWLY PUSH S INTO THE WATERS SAT NIGHT AND SUN
THEN IS EXPECTED TO PUSH S OF THE WATERS BY MON WITH NLY WINDS
DEVELOPING.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR AMZ130-
135.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT SUNDAY FOR AMZ152-154-156-
158.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR AMZ150.
&&
$$
SYNOPSIS...BTC
NEAR TERM...CGG
SHORT TERM...BTC
LONG TERM...CGG
AVIATION...SK
MARINE...SK
000
FXUS62 KILM 071442
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1041 AM EDT THU MAY 7 2009
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A SHORTWAVE TROUGH WILL
MOVE EAST OF THE AREA AROUND MIDDAY. WARMER AND DRIER WEATHER WILL
PREVAIL ON FRIDAY AND SATURDAY AS HIGH PRESSURE BUILDS INTO THE
REGION. A COLD FRONT WILL MOVE ACROSS THE AREA SUNDAY AND STALL ON
MONDAY BEFORE BRINGING DRIER AIR FOR THE EARLY PART OF NEXT
WEEK...AS HIGH PRESSURE BUILDS INTO THE REGION FROM THE NORTH
THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 10 AM THURSDAY...MID LEVEL SHORTWAVE WILL MOVE OFF THE COAST
THROUGH MIDDAY. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO CLEAR
COAST AREAS BY AROUND NOON. SUBSIDENCE AND DRIER AIR IN THE WAKE OF
THIS FEATURE IS EXPECTED TO KEEP CONVECTION THIS AFTERNOON ISOLATED
TO PERHAPS SCATTERED. IN ORDER FOR STORMS TO REFIRE...AND IN THE
ABSENCE OF ANY NOTABLE TRIGGERS ALOFT...WE ARE GOING TO HAVE TO
RECEIVE SOME GOOD INSOLATION. IT DOES APPEAR THAT WITH DRIER AIR
WORKING IN FROM THE W THAT THIS WILL BE THE CASE. TEMPS SHOULD
RESPOND...REACHING WELL INTO THE 80S. THUNDERSTORMS THIS AFTERNOON
COULD PRODUCE ISOLATED STRONG TO DAMAGING WIND GUSTS. HAIL RISK IS
LOW GIVEN WET BULB ZEROS ABOVE 12KFT.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...FLAT PROGRESSIVE 5H PATTERN REMAINS IN
PLACE THROUGH THE PERIOD AND WILL KEEP STALLED SURFACE BOUNDARY
JUST NORTH OF THE AREA. WEAK SHORTWAVES PASSING NORTH OF THE AREA
MAY NOT BE CLOSE ENOUGH TO HAVE AN IMPACT ON THE AREA. EVEN IF A
WAVE WERE TO MOVE ACROSS THE AREA THERE IS A LOT OF DRY AIR AND A
CAP FROM 900 TO 800 MB THAT WOULD TEND TO SUPPRESS CONVECTION. SEA
BREEZE MIGHT BE ABLE TO PROVIDE ENOUGH LIFT TO OVER COME THE CAP
ON FRI...WHEN CAP IS A LITTLE WEAKER AND THERE IS A LITTLE MORE
MOISTURE AVAILABLE. WILL CARRY LOW CHANCE POP INLAND FRI WITH
SLIGHT CHANCE CLOSER TO THE COAST...WHICH IS PROBABLY ON THE
GENEROUS SIDE.
HOLDING ONTO SLIGHT CHANCE POPS FOR SAT FOR NOW BUT ITS LOOKING LESS
LIKELY. PRECIP HOPES WILL BE TIED TO PVA AHEAD OF SHORTWAVE SAT
NIGHT...AND THE GUIDANCE HAS BEEN FIGHTING FEEDBACK WHICH AFFECTS
TIMING AND STRENGTH OF THESE WAVES. TEMPERATURES WILL RUN 5 TO 10
DEGREES ABOVE CLIMO BOTH DAY AND NIGHT...WITH READINGS A LITTLE
CLOSER TO CLIMO NEARER TO THE COAST.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 3 AM THURSDAY...PROGRESSIVE FLAT 5H PATTERN CONTINUES
THROUGH MUCH OF THE PERIOD. SURFACE BOUNDARY THAT HAS BEEN STALLED
NORTHWEST OF THE AREA WILL START HAVING A DIRECT IMPACT ON THE
AREA LATER SUN AND CONTINUING THROUGH AT LEAST MON NIGHT. 12Z
ECMWF PUSHES THE FRONT SOUTH OF THE AREA TUE AS HIGH PRESSURE
BUILDS IN FROM THE NORTH. THE 00Z GFS IS IN SOMEWHAT GOOD
AGREEMENT WITH THIS TIMING...THOUGH IT SHOULD BE NOTED THAT EVERY
24 HOURS IT SEEMS FROPA IS AGAIN BEING DELAYED.
PRECIP CHANCES WILL MAINLY BE DEPENDANT ON TIMING OF SHORTWAVE
PASSAGE AND OTHER THAN A GENERAL TIME RANGE...SUN NIGHT AND AGAIN
MON AFTN...CANNOT GET TO PRECISE. ALSO EXPECT DIURNALLY DRIVEN
INSTABILITY AND THE SEA BREEZE TO PRODUCE SOME CONVECTION...BUT
COVERAGE WILL REMAIN LIMITED. TEMPERATURES SUN AND MON WILL BE NEAR
CLIMO...MAINLY DUE TO INCREASING CLOUD COVER THOUGH HEIGHTS DO DROP
A BIT ON MON AS SOUTHERN BRANCH OF JET STREAM SAGS SOUTH. IF LATEST
GFS AND 12Z ECMWF ARE TO BE BELIEVED...TUE AND WED WILL BE DRY WITH
TEMPERATURES BELOW CLIMO.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
THUNDERSTORMS HAVE EXITED THE FLO TERMINAL AND WILL EXIT THE LBT
TERMINAL BY TAF ISSUANCE TIME. AT FLO/LBT MVFR CEILINGS WILL BE
LIKELY THROUGH THE MORNING HOURS WITH SHOWER POTENTIAL ENDING BY
MID-MORNING. LIGHT WEST-SOUTHWEST WINDS WILL BECOME SOUTH SOUTHWEST
BY EARLY AFTERNOON AT 10-18 KNOTS WITH VFR CEILINGS AND NO
PRECIPITATION.
THUNDERSTORMS WILL APPROACH THE COASTAL TERMINALS EARLY THIS
MORNING. RADAR LOOPS SUGGEST MOST ACTIVITY WILL MISS THE MYR
TERMINAL TO THE NORTH. CRE WILL BE ON THE SOUTHERN EDGE OF THE
ACTIVITY WITH ILM STANDING THE BEST SHOT AT THUNDERSTORM OCCURRENCE.
TEMPO MVFR CONDITIONS EXPECTED WITH THIS ACTIVITY EXCEPT FOR TEMPO
IFR AT ILM. TEMPO MVFR CEILINGS WILL THEN BE POSSIBLE THROUGH
NOON AT THE COASTAL TERMINALS. THUNDERSTORM POTENTIAL SHOULD END
BY MID MORNING. CONFIDENCE IS LOW AS TO WHETHER THUNDERSTORMS WILL
RE FIRE THIS AFTERNOON. BEST POTENTIAL SHOULD BE AT MYR/CRE.
THERE WILL BE A CHANCE OF IFR VISIBILITIES AT FLO/LBT OVERNIGHT.
COASTAL TERMINALS SHOULD REMAIN VFR.
EXTENDED OUTLOOK THROUGH MONDAY...SCATTERED THUNDERSTORMS
THURSDAY AND SUNDAY. ISOLATED THUNDERSTORMS FRIDAY AND SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 10 AM THURSDAY...STRONG THUNDERSTORMS MOVING ACROSS THE
COASTAL WATERS THROUGH EARLY AFTERNOON WILL CONTINUE TO CHURN UP THE
SEAS AND WILL MAINTAIN SMALL CRAFT ADVISORY AND EXERCISE CAUTION
HEADLINES. SE SWELL AROUND 9 SECONDS IS STILL EVIDENT AND IS NOT
EXPECTED TO CHANGE THROUGH THE PERIOD. WIND DIRECTION WILL REMAIN
FROM THE SSW TO SW THROUGH THE PERIOD.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...SOUTH TO SOUTHWEST FLOW WILL CONTINUE OVER THE
WATERS DURING THE PERIOD. GFS WIND SPEEDS HAVE CONSISTENTLY BEEN TO
HIGH...LIKELY DUE TO AIR/SEA INTERFACE ISSUES...SO FAVORING THE NAM
FOR SPEEDS. ISSUES WITH GFS WIND SPEEDS ALSO CAUSES WWIII GUIDANCE
TO BE ON THE HIGH SIDE. WILL KNOCK ABOUT A FOOT OFF WITH SLIGHT
TWEAKS DUE TO PROLONGED SOUTHERLY FETCH.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 AM THURSDAY...FRONT WILL BE IN THE AREA SUN AND MON MAKING
WIND DIRECTION FORECAST QUITE DIFFICULT. LUCKILY WITH THE FRONT
DRAPED ACROSS THE WATERS GRADIENT WILL BE VERY WEAK AND SPEEDS
WILL BE UNDER 10 KT BUT HIGHLY VARIABLE. EVENTUALLY WINDS WILL
DEVELOP A NORTHERLY COMPONENT BUT THAT MAY NOT OCCUR UNTIL AFTER
THE END OF THE FORECAST PERIOD. LEFT OVER SWELL FROM PROLONGED
PERIOD OF SOUTHERLY FETCH WILL KEEP SEAS RUNNING A LITTLE HIGHER
THAN SPEEDS WOULD SUGGEST. SEAS 3 TO 5 FT ON SUN SUBSIDING TO 2 TO
3 FT FOR MON.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT FRIDAY FOR AMZ250-252.
&&
$$
NEAR TERM...RJD
SHORT TERM...III
LONG TERM...III
AVIATION...MRR
000
FXUS62 KMHX 071359
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
1000 AM EDT THU MAY 7 2009
.SYNOPSIS...
HIGH PRESSURE WILL BE CENTERED IN THE WESTERN ATLANTIC THROUGH
SATURDAY. MEANWHILE A COLD FRONT EAST OF THE APPALACHIANS WILL
MOVE SLOWLY SOUTHEAST TODAY THEN DISSIPATE JUST NORTHWEST OF THE
AREA TONIGHT. A SECONDARY COLD FRONT WILL APPROACH FROM THE
NORTHWEST ON SATURDAY AND MOVE SLOWLY THROUGH THE AREA SATURDAY
NIGHT THROUGH SUNDAY. HIGH PRESSURE GRADUALLY BUILDS INTO THE AREA
FROM THE NORTH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
CONVECTION BLOSSOMING EARLY THIS MORN NEAR I95 ALONG THE NC/SC
BORDER ASSOCD WITH A LEAD SHORTWAVE OUT AHEAD OF MAIN MID LVL
TROF. THIS PCPN WILL MOVE NE AND AFFECT MAINLY CSTL PLAIN THRU
SUNRISE. EXPECT THIS ACTIVITY TO PICK UP IN INTENSITY AS IT MOVES
INTO AREA OF MODEST INSTABILITY/LLJ EAST OF I95. WL NEED TO
MONITOR FOR SVR THREAT WITH DAMAGING WIND GUSTS BEING THE MAIN
THREAT FOR THE FIRST PART OF THE DAY.
THIS FIRST BATCH OF CONVECTION WILL BE MOVE NE AND ACRS OBX
DURING THE LATE MORN/EARLY AFTN. MID LVL FLOW TURNS WESTERLY WITH
AFTN SUBSIDENCE DOMINANT AFTER PASSAGE OF INITIAL SHORT WAVE. A
SECONDARY BAND OF CONVECTION MAY DEVELOP LATE THIS AFTN OR EARLY
EVE WITH MAIN SHORT WAVE. ANY ASSOCD PCPN LOOKS TO BE MOVING OFF
OBX BY EARLY MORN.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
RELATIVELY BENIGN WEATHER STARTS OUT THIS FCST PERIOD WITH ONLY
WEAK PERTURBATIONS IN THE FLAT MID LVL FLOW TO GENERATE ORGANIZED
CONVECTION. COULD STILL SEE ISOLD/SCTD CONVECTION FIRING ON ANY
LOCALIZED BNDRYS MAINLY DURING PEAK HEAT CYCLES. AN INCREASED CHC
OF SCTD CONVECTION AS A BETTER DEFINED SHORT WAVE TROF APPROACHES
SAT AFTN.
HIGH TEMPS THIS FCST PERIOD WELL INTO THE 80S AND MAY APPROACH
90F INLAND GIVEN THE INCREASED SUNSHINE...LOW LVL THICKNESS
VALUES AND DOWNSLOPE FLOW.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
FRNT WL BE S OF AREA BY SUN. ANTHR SURGE WL PUSH THRU SUN AFTN AND
NGT. 5H FLO TO BCM MR AMPLIFIED OVR THE ECST MON AND A WV FRMS ON
THE FRNT TO OUR S. CUD SEE SUM OVRRNNG PCPN FRM THIS WV MON AND MON
NGT. HI PRES BOTH AT THE SFC AND ALFT WL BLD IN TUE NGT. THIS RDG WL
MV OFFSHR THU.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
VFR ACROSS MOST OF RTES EARLY THIS MORNING...HOWEVER PATCHY STCU
BRINGING PERIODS OF MVFR CIGS AT A COUPLE OF THE TERMINALS
INCLUDING OAJ. A ROBUST SHORTWAVE AND SFC TROUGH APPROACHING THE
REGION EARLY THIS MORNING AND EXPECT SHOWERS AND TSTMS TO BEGIN TO
MOVE INTO RTES AFTER 10Z BRINGING AREAS OF MVFR TO LOCALLY IFR
CONDITIONS IN HEAVIEST SHOWERS. GREATEST COVERAGE OF SHOWERS
EXPECTED THROUGH THE MORNING HOURS AS THE VORT MAX CROSSES THE
REGION BUT PLENTY OF INSTABILITY AND MOISTURE REMAINS THIS
AFTERNOON FOR CONTINUED CONVECTION. ANOTHER VORT MAX CROSSES THE
REGION LATE TONIGHT WHICH COULD BRING A FEW SHOWERS OR ISOLATED
THUNDERSTORMS ACROSS RTES.
WAVES OF LOW PRES CONTINUE TO LIFT NE ALONG A STALLED FRONT TO THE
NW THROUGH THE REMAINDER OF THE WEEK. MAINLY VFR CONDITIONS
EXPECTED THROUGH THE LONG TERM BUT COULD SEE PERIODS OF SHOWERS
AND MAINLY AFTERNOON CONVECTION. A FRONT PUSHES THROUGH THE REGION
SUN BUT ANOTHER WAVE OF LOW PRES WILL CONTINUE TO BRING A CHANCE
OF SHOWERS THROUGH MON.
&&
.MARINE...
MODERATE SOUTHERLY FLOW CONTINUES ACROSS THE WATERS AS A SURFACE
TROUGH APPROACHES THE REGION. WINDS STRONGEST ACROSS THE SOUNDS
AND N OF HATTERAS WHERE 20-25 KT REPORTED AT OB SITES WHILE 10-15
KT REPORTED ACROSS SRN MOST WATERS. SEAS HAVE BUILT TO 6 FT AT
DIAMOND BUOY BUT 4-5 FT REPORTED AT OTHER BUOYS. GFS OVERDONE ON
WINDS...ESPECIALLY ACROSS CENTRAL AND SOUTHERN WATERS WHICH HAS
ALLOWED WAVEWATCH TO OVERESTIMATE SEAS BY A FOOT OR TWO. WILL
CONTINUE SCA TODAY ACROSS ALL WATERS BUT COULD BE MINIMAL IN SOME
AREAS...MAINLY SRN WATERS...BUT STILL COULD SEE SEAS TO 6 FT
ACROSS OUTER PORTIONS AND DON`T WANT TO DROP PREMATURELY.
THERE WILL BE LITTLE CHANGE IN THE WX PATTERN THROUGH SAT NIGHT
WITH THE BERMUDA HIGH REMAINING ACROSS THE WRN ATLANTIC AND
SEVERAL SFC TROUGHS OR AREAS OF LOW PRES PASSING NW OF THE WATERS.
MODERATE SLY FLOW EXPECTED TO CONTINUE THROUGH THIS PERIOD AND
SEAS TO 6 FT WILL BE POSSIBLE ACROSS THE OUTER PORTIONS OF THE
WATERS FROM DIAMOND SHOALS S SO WILL MAINTAIN SCA FOR THE PERIOD.
SAT WILL SEE STRONGEST FLOW WITH SCA CONDITIONS LIKELY ACROSS ALL
WATERS AS LOW PRES MOVE ACROSS THE MID ATLANTIC. THE SFC TROUGH
FINALLY BEGINS TO SLOWLY PUSH S INTO THE WATERS SAT NIGHT AND SUN
THEN IS EXPECTED TO PUSH S OF THE WATERS BY MON WITH NLY WINDS
DEVELOPING.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR AMZ130-
135.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT SUNDAY FOR AMZ152-154-156-
158.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR AMZ150.
&&
$$
SYNOPSIS...BTC
NEAR TERM...BTC
SHORT TERM...BTC
LONG TERM...CGG
AVIATION...SK
MARINE...SK
000
FXUS62 KILM 071156
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
756 AM EDT THU MAY 7 2009
.SYNOPSIS...
A SHORTWAVE PASSING JUST NORTH OF THE AREA MAY PRODUCE SCATTERED
SHOWER AND THUNDERSTORM ACTIVITY TODAY. WARMER AND DRIER WEATHER
WILL PREVAIL ON FRIDAY AND SATURDAY AS HIGH PRESSURE BUILDS INTO
THE REGION. A COLD FRONT WILL MOVE ACROSS THE AREA SUNDAY AND
STALL ON MONDAY BEFORE BRINGING DRIER AIR FOR THE EARLY PART OF
NEXT WEEK...AS HIGH PRESSURE BUILDS INTO THE REGION FROM THE NORTH
THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM THURSDAY...5H S/W TROF TO MOVE ACROSS THE ILM CWA THIS
MORNING THROUGH MIDDAY. AT THE MOMENT ITS LIKELY AIDING THE
RE-FIRING OF THE LINE OF CONVECTION THAT NEARLY DISSIPATED EARLIER.
ONCE MAYS INSOLATION MAKES ITSELF KNOWN...WOULD EXPECT A FURTHER
DESTABILIZATION OF THE ATMOSPHERE I.E. THE NAM BUFR SOUNDINGS
INDICATE CAPE BETWEEN 2.4 TO 2.7K JUST SEVERAL HRS AFTER SUNRISE
ACROSS THE ILM CWA. IN ADDITION...ALTHOUGH WEAK...A SFC COLD/COOL
FRONT/BOUNDARY WILL ALSO BE IN THE VICINITY TO FURTHER AID TODAYS
CONVECTION. THERE4...FEEL COMFORTABLE WITH 50 POPS ACROSS THE
MAJORITY OF THE ILM CWA. IN ADDITION...THE SEVERITY OF THE
CONVECTION IS HIGHLIGHTED ONCE AGAIN ACROSS THE ILM CWA BY
SPC...WITH HAIL AND DAMAGING WIND GUSTS THE PRIMARY POTENTIALS. WILL
HOLD OFF FROM PLACING IN THE ACTUAL FORECASTS BUT HIGHLIGHT IN THE
HAZARDOUS WEATHER OUTLOOK. TODAYS MAX AND TONIGHTS MIN FCSTS LOOK
AOK WITH VERY LITTLE CHANGES NEEDED GIVEN LATEST VARIOUS MODEL MOS
GUIDANCE CONTINUING ITS CONSISTENCY FROM MODEL RUN TO RUN.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...FLAT PROGRESSIVE 5H PATTERN REMAINS IN
PLACE THROUGH THE PERIOD AND WILL KEEP STALLED SURFACE BOUNDARY
JUST NORTH OF THE AREA. WEAK SHORTWAVES PASSING NORTH OF THE AREA
MAY NOT BE CLOSE ENOUGH TO HAVE AN IMPACT ON THE AREA. EVEN IF A
WAVE WERE TO MOVE ACROSS THE AREA THERE IS A LOT OF DRY AIR AND A
CAP FROM 900 TO 800 MB THAT WOULD TEND TO SUPPRESS CONVECTION. SEA
BREEZE MIGHT BE ABLE TO PROVIDE ENOUGH LIFT TO OVER COME THE CAP
ON FRI...WHEN CAP IS A LITTLE WEAKER AND THERE IS A LITTLE MORE
MOISTURE AVAILABLE. WILL CARRY LOW CHANCE POP INLAND FRI WITH
SLIGHT CHANCE CLOSER TO THE COAST...WHICH IS PROBABLY ON THE
GENEROUS SIDE.
HOLDING ONTO SLIGHT CHANCE POPS FOR SAT FOR NOW BUT ITS LOOKING LESS
LIKELY. PRECIP HOPES WILL BE TIED TO PVA AHEAD OF SHORTWAVE SAT
NIGHT...AND THE GUIDANCE HAS BEEN FIGHTING FEEDBACK WHICH AFFECTS
TIMING AND STRENGTH OF THESE WAVES. TEMPERATURES WILL RUN 5 TO 10
DEGREES ABOVE CLIMO BOTH DAY AND NIGHT...WITH READINGS A LITTLE
CLOSER TO CLIMO NEARER TO THE COAST.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 3 AM THURSDAY...PROGRESSIVE FLAT 5H PATTERN CONTINUES
THROUGH MUCH OF THE PERIOD. SURFACE BOUNDARY THAT HAS BEEN STALLED
NORTHWEST OF THE AREA WILL START HAVING A DIRECT IMPACT ON THE
AREA LATER SUN AND CONTINUING THROUGH AT LEAST MON NIGHT. 12Z
ECMWF PUSHES THE FRONT SOUTH OF THE AREA TUE AS HIGH PRESSURE
BUILDS IN FROM THE NORTH. THE 00Z GFS IS IN SOMEWHAT GOOD
AGREEMENT WITH THIS TIMING...THOUGH IT SHOULD BE NOTED THAT EVERY
24 HOURS IT SEEMS FROPA IS AGAIN BEING DELAYED.
PRECIP CHANCES WILL MAINLY BE DEPENDANT ON TIMING OF SHORTWAVE
PASSAGE AND OTHER THAN A GENERAL TIME RANGE...SUN NIGHT AND AGAIN
MON AFTN...CANNOT GET TO PRECISE. ALSO EXPECT DIURNALLY DRIVEN
INSTABILITY AND THE SEA BREEZE TO PRODUCE SOME CONVECTION...BUT
COVERAGE WILL REMAIN LIMITED. TEMPERATURES SUN AND MON WILL BE NEAR
CLIMO...MAINLY DUE TO INCREASING CLOUD COVER THOUGH HEIGHTS DO DROP
A BIT ON MON AS SOUTHERN BRANCH OF JET STREAM SAGS SOUTH. IF LATEST
GFS AND 12Z ECMWF ARE TO BE BELIEVED...TUE AND WED WILL BE DRY WITH
TEMPERATURES BELOW CLIMO.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
THUNDERSTORMS HAVE EXITED THE FLO TERMINAL AND WILL EXIT THE LBT
TERMINAL BY TAF ISSUANCE TIME. AT FLO/LBT MVFR CEILINGS WILL BE
LIKELY THROUGH THE MORNING HOURS WITH SHOWER POTENTIAL ENDING BY
MID-MORNING. LIGHT WEST-SOUTHWEST WINDS WILL BECOME SOUTH SOUTHWEST
BY EARLY AFTERNOON AT 10-18 KNOTS WITH VFR CEILINGS AND NO
PRECIPITATION.
THUNDERSTORMS WILL APPROACH THE COASTAL TERMINALS EARLY THIS
MORNING. RADAR LOOPS SUGGEST MOST ACTIVITY WILL MISS THE MYR
TERMINAL TO THE NORTH. CRE WILL BE ON THE SOUTHERN EDGE OF THE
ACTIVITY WITH ILM STANDING THE BEST SHOT AT THUNDERSTORM OCCURRENCE.
TEMPO MVFR CONDITIONS EXPECTED WITH THIS ACTIVITY EXCEPT FOR TEMPO
IFR AT ILM. TEMPO MVFR CEILINGS WILL THEN BE POSSIBLE THROUGH
NOON AT THE COASTAL TERMINALS. THUNDERSTORM POTENTIAL SHOULD END
BY MID MORNING. CONFIDENCE IS LOW AS TO WHETHER THUNDERSTORMS WILL
RE FIRE THIS AFTERNOON. BEST POTENTIAL SHOULD BE AT MYR/CRE.
THERE WILL BE A CHANCE OF IFR VISIBILITIES AT FLO/LBT OVERNIGHT.
COASTAL TERMINALS SHOULD REMAIN VFR.
EXTENDED OUTLOOK THROUGH MONDAY...SCATTERED THUNDERSTORMS
THURSDAY AND SUNDAY. ISOLATED THUNDERSTORMS FRIDAY AND SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM THURSDAY...A DECENT SOUTHERLY FETCH WITH WIND SPEEDS
IN THE 15-20 KT RANGE IS EXPECTED TO FURTHER INCREASE CURRENT SEAS
TO SCA THRESHOLDS BY SUNRISE. AS A RESULT...DO NOT SEE A NEED TO
RE-VISIT THE TIMING OF THE START OF THE CURRENT SCA ACROSS THE 2
NORTHERN ZONES. THE SCEC FOR THE SOUTHERN 2 ZONES ALSO STILL LOOKS
ON TARGET. WAVEWATCH3 THIS TIME LOOKS AS IF IT MAY BE CATCHING UP TO
REALITY. OF NOTE...FOR THE PAST SEVERAL DAYS UNDER AN ONSHORE
SOUTHERLY COMPONENT WITHIN THE WIND FIELD...SSTS HAVE STEADILY
INCREASED TO THE LOWER 70S WITH SOME MID 70S BEING REPORTED. THIS
MARINE LAYER AT THE MOMENT REMAINS A HINDRANCE TO CONVECTION WHEN
ENCOUNTERING IT FROM THE WEST...HOWEVER IF SSTS CONTINUE THEIR
CURRENT UPWARD MOMENTUM...THE MARINE LAYER BEHIND THE SEA BREEZE
WILL NO LONGER BE THAT AUTOMATIC KILLER FOR CONVECTION THAT USUALLY
COMMENCES MID SUMMER.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...SOUTH TO SOUTHWEST FLOW WILL CONTINUE OVER THE
WATERS DURING THE PERIOD. GFS WIND SPEEDS HAVE CONSISTENTLY BEEN TO
HIGH...LIKELY DUE TO AIR/SEA INTERFACE ISSUES...SO FAVORING THE NAM
FOR SPEEDS. ISSUES WITH GFS WIND SPEEDS ALSO CAUSES WWIII GUIDANCE
TO BE ON THE HIGH SIDE. WILL KNOCK ABOUT A FOOT OFF WITH SLIGHT
TWEAKS DUE TO PROLONGED SOUTHERLY FETCH.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 AM THURSDAY...FRONT WILL BE IN THE AREA SUN AND MON MAKING
WIND DIRECTION FORECAST QUITE DIFFICULT. LUCKILY WITH THE FRONT
DRAPED ACROSS THE WATERS GRADEINT WILL BE VERY WEAK AND SPEEDS
WILL BE UNDER 10 KT BUT HIGHLY VARIABLE. EVENTUALLY WINDS WILL
DEVELOP A NORTHERLY COMPONENT BUT THAT MAY NOT OCCUR UNTIL AFTER
THE END OF THE FORECAST PERIOD. LEFT OVER SWELL FROM PROLONGED
PERIOD OF SOUTHERLY FETCH WILL KEEP SEAS RUNNING A LITTLE HIGHER
THAN SPEEDS WOULD SUGGEST. SEAS 3 TO 5 FT ON SUN SUBSIDING TO 2 TO
3 FT FOR MON.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT FRIDAY FOR AMZ250-252.
&&
$$
NEAR TERM...DCH
SHORT TERM...III
LONG TERM...III
AVIATION...MRR
000
FXUS62 KRAH 071123
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
723 AM EDT THU MAY 7 2009
.SYNOPSIS...
A STRONG UPPER LEVEL DISTURBANCE WILL PIVOT ACROSS THE AREA BY
MIDDAY...BRINGING ANOTHER ROUND SHOWERS AND THUNDERSTORMS ACROSS
CENTRAL NORTH CAROLINA THROUGH THE AFTERNOON. A WEAK SURFACE TROUGH
WILL THEN LINGER ACROSS THE CAROLINAS THROUGH SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM THURSDAY...
THE BROKEN CONVECTIVE LINE CURRENTLY MOVING THROUGH THE CENTRAL
PIEDMONT IS ASSOCIATED WITH THE 50KT LOW-LEVEL JET BUT IS REALLY
HAVING A HARD TIME BECOMING ORGANIZED AS BOUNDARY LAYER CIN HAS
REALLY DETERRED THE UPDRAFT STRENGTH. HOWEVER...WE STILL HAVE THE
BETTER UPPER DYNAMICS UPSTREAM...AS THE POTENT MID AND UPPER LEVEL
TROUGH OVER EASTERN TN PIVOTS ACROSS CENTRAL NC BETWEEN 09 TO 15Z.
THE COLD CORE ALOFT WILL BRING STEEP MID-LEVEL LAPSE RATES THROUGH
THE INTERSTATE 77 CORRIDOR...NEAR BOONE...AND UP INTO BLACKSBURG VA
WITH STRONG UPPER DIVERGENCE OVERSPREADING ENTIRE THE AREA AS RIGHT
ENTRANCE REGION OF UPPER JET TRAVERSES THE AREA. GIVEN THE HIGH PWAT
AIRMASS...THIS SHOULD ALLOW FOR WIDESPREAD COVERAGE THROUGH THE RUSH
HOUR MORNING COMMUTE...WITH THE POTENTIAL FOR THE STORMS TO BECOME
BETTER ORGANIZE/STRENGTHEN AS IT ENCOUNTERS THE MORE UNSTABLE AIRMASS
RESIDING IN THE COASTAL PLAIN...PER LATEST SPC MESOANALYSIS OF 500
TO 1000 J/KG IN THE AREA.
THIS AREA OF CONVECTION IS EXPECTED TO PUSH EAST OF THE AREA BY 15
TO 16Z...AS THE SURFACE TROUGH STALLS OUT ACROSS THE WESTERN
PIEDMONT. INCREASING WESTERLY FLOW ALOFT...BEHIND THE UPPER WAVE
WILL RESULT IN A SCATTERING OUT OF THE BROKEN CLOUD
COVER...RESULTING IN DECENT SURFACE HEATING WITH TEMPERATURES
CLIMBING INTO THE LOWER TO MID 80S. WITH AFTERNOON LOW-LEVEL LAPSE
RATES STEEPENING AOA 8.5 C/KM WITH PWATS STILL AROUND 1.1 TO
1.2"...CONVECTION IS EXPECTED TO RE-DEVELOP THIS AFTERNOON WITH BOTH
THE NAM AND GFS SHOWING SUBTLE S/W IMPULSES IN THE WESTERLY FLOW
ALOFT. MODERATE INSTABILITY OF 1500 TO 2000 J/KG WITH 30 TO 40 KTS
OF BULK SHEAR WILL SUPPORT STRONG TO SEVERE STORMS WITH PRECIP
LOADING BRINGING A THREAT OF WET MICROBURSTS...AND LOWERING WET-BULB
ZEROS OF 8.5-9.0 KFT BRINGING A THREAT OF LARGE HAIL. THE CONVECTION
WILL BE LARGELY DIURNALLY DRIVEN AND SHOULD QUICKLY DIMINISH SHORTLY
AFTER SUNSET. UNDER PARTLY CLOUDY SKIES AND A LIGHT
WEST-SOUTHWESTERLY WIND FLOW... OVERNIGHT LOWS WILL COOL INTO THE
LOWER TO MID 60S.
.
&&
.SHORT TERM /FRIDAY/...
AS OF 325 AM THURSDAY...
THICKNESSES INCREASE AOA 1410 TO 1415 FRIDAY AFTERNOON SUPPORTING
AFTERNOON HIGHS OF 85 TO 90 ACROSS THE AREA. THE STRONG SURFACE
HEATING WILL SUPPORT A MODERATELY UNSTABLE AIRMASS AS
PIEDMONT SURFACE TROUGH RESIDES IN THE LEE OF THE APPALACHIANS WITH
PWATS INCREASING TO 1.3 TO 1.4". WHILE UPPER JET CORE WILL BE WELL
NORTH OF THE AREA ACROSS OHIO VALLEY AND MID ATLANTIC STATES...S/W
VORTS...POSSIBLY CONVECTIVELY INDUCED IN NATURE IS PROGGED BY BOTH
THE GFS AND NAM TO SPREAD EAST ACROSS THE AREA FRIDAY
AFTERNOON...WITH 40 TO 50KTS OF WEST-NORTHWEST DEEP LAYER SHEAR.
FOR NOW WILL GO WITH SCATTERED...30 TO 40 PERCENT POP WITH A SLIGHT
RISK OF SEVERE STORMS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
AS OF 330 AM THURSDAY...
A DIFFICULT PRECIP FORECAST FOR FRIDAY NIGHT AS IT IS TOUGH TO
ASCERTAIN THE DEVELOPMENT AND EVOLUTION OF ANY MCVS TO OUR WEST THAT
COULD APPROACH THE AREA OVERNIGHT. THE GFS IS THE STRONGEST WITH
SUCH A SHORTWAVE...GENERATING A RATHER ROBUST SFC LOW JUST NORTH OF
THE VA/NC BORDER. THE ECMWF/NAM ARE WEAKER AND FURTHER NORTH WITH
THIS ACTIVITY. IF A MCV DOES TRACK ACROSS THE REGION...IT WOULD
ENCOUNTER ENOUGH LINGERING INSTABILITY (500-800 J/KG MUCAPE) WITH
DEWPOINTS IN THE MID 60S TO PRODUCE SCATTERED CONVECTION. WILL KEEP
POPS ON THE LOW SIDE AND HIGHEST (30%) IN THE FAR NORTH DUE TO THE
UNCERTAINTY. LOWS A VERY MILD AND MUGGY 64-68.
A COLD FRONT WILL BEGIN TO APPROACH FROM THE NORTHWEST BY LATE
SATURDAY AFTERNOON AS A MID LEVEL TROUGH OVER THE GREAT LAKES
BEGINS TO MOVE EAST TOWARD NEW ENGLAND. EXPECT SCATTERED SHOWERS AND
THUNDERSTORMS TO DEVELOP ALONG AND AHEAD OF THE FRONT AS IT
ENCOUNTERS AN UNSTABLE AIRMASS REPRESENTED WITH MLCAPES ABOVE 1000
J/KG. THE BEST MID LEVEL FORCING STAYS WELL TO OUR NORTH...SO WILL
KEEP POPS IN THE CHANCE CATEGORY. THICKNESSES SOAR INTO THE
1410-1420M RANGE...SUPPORTING UPPER 80S TO LOWER 90S FOR HIGHS. THE
FRONT MOVES THROUGH SATURDAY NIGHT WITH A CONTINUED CHANCE FOR
SCATTERED CONVECTION...BUT AS INSTABILITY WANES OVERNIGHT AND THE
LACK OF ANY LARGE SCALE FORCING...PRECIP CHANCES WILL GRADUALLY
DIMINISH. LOWS 60-67.
GUIDANCE IS COMING INTO BETTER AGREEMENT ON STALLING THE COLD FRONT
JUST TO THE SOUTH OF THE CWA SUNDAY AND MONDAY WITH THE 850 MB FRONT
STALLING OVERHEAD. AS SUBTLE PIECES OF ENERGY MOVE THROUGH THE ZONAL
FLOW ALOFT...PERIODS OF OVERRUNNING PRECIPITATION WILL BE POSSIBLE.
RAIN CHANCES LOOK TO TAPER OFF BY TUESDAY MORNING AS A STRONGER
SHORTWAVE OVER THE NORTH CENTRAL STATES DIVES SOUTHEAST INTO THE MID
ATLANTIC AND PUSHES THE FRONT FURTHER SOUTH AND EAST. TEMPS THROUGH
THIS PERIOD WILL RETURN TO MORE SEASONABLE LEVELS...DUE TO THE
COMBINATION OF COOL HIGH PRESSURE BUILDING IN ALONG WITH INCREASED
CLOUD COVER PARTICULARLY ON SUNDAY/MONDAY. HIGHS GENERALLY IN THE
70S AND LOWS IN THE 50S.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 720 AM THURSDAY...
WIDESPREAD SHOWERS WITH SCATTERED THUNDERSTORMS...ASSOCIATED WITH A
STRONG UPPER LEVEL SHORTWAVE TROUGH...WILL CONTINUE TO PUSH WEST TO
EAST ACROSS THE FORECAST AREA...BRINGING A 2 TO 3 HOUR PERIOD OF
MVFR CONDITIONS...ESPECIALLY FROM RDU EAST. THE THUNDER REMAINS
CONFINED ACROSS THE SANDHILLS AND COASTAL PLAIN ALONG THE
INSTABILITY AXIS. THESE STORMS LOOK TO EXIT EAST OF THE AREA BY 15
TO 16Z.
CEILINGS SHOULD SCATTER OUT TO VFR BY LATE MORNING...AND THEN BECOME
BROKEN AGAIN AS STRONG AFTERNOON HEATING WILL ALLOW FOR CONVECTION
TO DEVELOP ALONG A WEAK SURFACE TROUGH LOCATED ACROSS THE WESTERN
PIEDMONT. LOSS OF DAYTIME HEATING SHOULD GREATLY DIMINISH CONVECTIVE
ACTIVITY WITH SCATTERED VFR CEILINGS OVERNIGHT.
UNSETTLED WEATHER EXPECTED FRIDAY NIGHT THROUGH MONDAY AS A COLD
FRONT APPROACHES THEN STALLS IN OUR VICINITY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...CBL
SHORT TERM...CBL
LONG TERM...JFB
AVIATION...CBL
000
FXUS62 KMHX 070934
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
534 AM EDT THU MAY 7 2009
.SYNOPSIS...
HIGH PRESSURE WILL BE CENTERED IN THE WESTERN ATLANTIC THROUGH
SATURDAY. MEANWHILE A COLD FRONT EAST OF THE APPALACHIANS WILL
MOVE SLOWLY SOUTHEAST TODAY THEN DISSIPATE JUST NORTHWEST OF THE
AREA TONIGHT. A SECONDARY COLD FRONT WILL APPROACH FROM THE
NORTHWEST ON SATURDAY AND MOVE SLOWLY THROUGH THE AREA SATURDAY
NIGHT THROUGH SUNDAY. HIGH PRESSURE GRADUALLY BUILDS INTO THE AREA
FROM THE NORTH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
CONVECTION BLOSSOMING EARLY THIS MORN NEAR I95 ALONG THE NC/SC
BORDER ASSOCD WITH A LEAD SHORTWAVE OUT AHEAD OF MAIN MID LVL
TROF. THIS PCPN WILL MOVE NE AND AFFECT MAINLY CSTL PLAIN THRU
SUNRISE. EXPECT THIS ACTIVITY TO PICK UP IN INTENSITY AS IT MOVES
INTO AREA OF MODEST INSTABILITY/LLJ EAST OF I95. WL NEED TO
MONITOR FOR SVR THREAT WITH DAMAGING WIND GUSTS BEING THE MAIN
THREAT FOR THE FIRST PART OF THE DAY.
THIS FIRST BATCH OF CONVECTION WILL BE MOVE NE AND ACRS OBX
DURING THE LATE MORN/EARLY AFTN. MID LVL FLOW TURNS WESTERLY WITH
AFTN SUBSIDENCE DOMINANT AFTER PASSAGE OF INITIAL SHORT WAVE. A
SECONDARY BAND OF CONVECTION MAY DEVELOP LATE THIS AFTN OR EARLY
EVE WITH MAIN SHORT WAVE. ANY ASSOCD PCPN LOOKS TO BE MOVING OFF
OBX BY EARLY MORN.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
RELATIVELY BENIGN WEATHER STARTS OUT THIS FCST PERIOD WITH ONLY
WEAK PERTURBATIONS IN THE FLAT MID LVL FLOW TO GENERATE ORGANIZED
CONVECTION. COULD STILL SEE ISOLD/SCTD CONVECTION FIRING ON ANY
LOCALIZED BNDRYS MAINLY DURING PEAK HEAT CYCLES. AN INCREASED CHC
OF SCTD CONVECTION AS A BETTER DEFINED SHORT WAVE TROF APPROACHES
SAT AFTN.
HIGH TEMPS THIS FCST PERIOD WELL INTO THE 80S AND MAY APPROACH
90F INLAND GIVEN THE INCREASED SUNSHINE...LOW LVL THICKNESS
VALUES AND DOWNSLOPE FLOW.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
INCOMING COLD FRONT WILL SLOW DOWN AS IT MOVES INTO THE AREA
DURING THE SECOND HALF OF THE WEEKEND. EVEN IF FRONT PUSHES ALL
THE WAY THROUGH WILL LIKELY SEE PERIODS OF CLOUDS AND SCTD PCPN
OVERRIDING THE FRONT TO THE SOUTH INTO MON/MON NIGHT. EAST COAST
TROF GRADUALLY SHARPENS EARLY NEXT WEEK AND THE VEERING STEERING
FLOW WILL EVENTUALLY SHOVE THE STALLED SFC BNDRY FARTHER DOWN THE
SE COAST WHICH WILL LEAD TO DRIER/COOLER CONDS ACRS THE FCST AREA
THRU MIDWEEK.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
VFR ACROSS MOST OF RTES EARLY THIS MORNING...HOWEVER PATCHY STCU
BRINGING PERIODS OF MVFR CIGS AT A COUPLE OF THE TERMINALS
INCLUDING OAJ. A ROBUST SHORTWAVE AND SFC TROUGH APPROACHING THE
REGION EARLY THIS MORNING AND EXPECT SHOWERS AND TSTMS TO BEGIN TO
MOVE INTO RTES AFTER 10Z BRINGING AREAS OF MVFR TO LOCALLY IFR
CONDITIONS IN HEAVIEST SHOWERS. GREATEST COVERAGE OF SHOWERS
EXPECTED THROUGH THE MORNING HOURS AS THE VORT MAX CROSSES THE
REGION BUT PLENTY OF INSTABILITY AND MOISTURE REMAINS THIS
AFTERNOON FOR CONTINUED CONVECTION. ANOTHER VORT MAX CROSSES THE
REGION LATE TONIGHT WHICH COULD BRING A FEW SHOWERS OR ISOLATED
THUNDERSTORMS ACROSS RTES.
WAVES OF LOW PRES CONTINUE TO LIFT NE ALONG A STALLED FRONT TO THE
NW THROUGH THE REMAINDER OF THE WEEK. MAINLY VFR CONDITIONS
EXPECTED THROUGH THE LONG TERM BUT COULD SEE PERIODS OF SHOWERS
AND MAINLY AFTERNOON CONVECTION. A FRONT PUSHES THROUGH THE REGION
SUN BUT ANOTHER WAVE OF LOW PRES WILL CONTINUE TO BRING A CHANCE
OF SHOWERS THROUGH MON.
&&
.MARINE...
MODERATE SOUTHERLY FLOW CONTINUES ACROSS THE WATERS AS A SURFACE
TROUGH APPROACHES THE REGION. WINDS STRONGEST ACROSS THE SOUNDS
AND N OF HATTERAS WHERE 20-25 KT REPORTED AT OB SITES WHILE 10-15
KT REPORTED ACROSS SRN MOST WATERS. SEAS HAVE BUILT TO 6 FT AT
DIAMOND BUOY BUT 4-5 FT REPORTED AT OTHER BUOYS. GFS OVERDONE ON
WINDS...ESPECIALLY ACROSS CENTRAL AND SOUTHERN WATERS WHICH HAS
ALLOWED WAVEWATCH TO OVERESTIMATE SEAS BY A FOOT OR TWO. WILL
CONTINUE SCA TODAY ACROSS ALL WATERS BUT COULD BE MINIMAL IN SOME
AREAS...MAINLY SRN WATERS...BUT STILL COULD SEE SEAS TO 6 FT
ACROSS OUTER PORTIONS AND DON`T WANT TO DROP PREMATURELY.
THERE WILL BE LITTLE CHANGE IN THE WX PATTERN THROUGH SAT NIGHT
WITH THE BERMUDA HIGH REMAINING ACROSS THE WRN ATLANTIC AND
SEVERAL SFC TROUGHS OR AREAS OF LOW PRES PASSING NW OF THE WATERS.
MODERATE SLY FLOW EXPECTED TO CONTINUE THROUGH THIS PERIOD AND
SEAS TO 6 FT WILL BE POSSIBLE ACROSS THE OUTER PORTIONS OF THE
WATERS FROM DIAMOND SHOALS S SO WILL MAINTAIN SCA FOR THE PERIOD.
SAT WILL SEE STRONGEST FLOW WITH SCA CONDITIONS LIKELY ACROSS ALL
WATERS AS LOW PRES MOVE ACROSS THE MID ATLANTIC. THE SFC TROUGH
FINALLY BEGINS TO SLOWLY PUSH S INTO THE WATERS SAT NIGHT AND SUN
THEN IS EXPECTED TO PUSH S OF THE WATERS BY MON WITH NLY WINDS
DEVELOPING.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR AMZ130-
135.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT SUNDAY FOR AMZ152-154-156-
158.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR AMZ150.
&&
$$
SYNOPSIS...BTC
NEAR TERM...BTC
SHORT TERM...BTC
LONG TERM...BTC
AVIATION...SK
MARINE...SK
000
FXUS62 KILM 070823
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
423 AM EDT THU MAY 7 2009
.SYNOPSIS...
A SHORTWAVE PASSING JUST NORTH OF THE AREA MAY PRODUCE SCATTERED
SHOWER AND THUNDERSTORM ACTIVITY TODAY. WARMER AND DRIER WEATHER
WILL PREVAIL ON FRIDAY AND SATURDAY AS HIGH PRESSURE BUILDS INTO
THE REGION. A COLD FRONT WILL MOVE ACROSS THE AREA SUNDAY AND
STALL ON MONDAY BEFORE BRINGING DRIER AIR FOR THE EARLY PART OF
NEXT WEEK...AS HIGH PRESSURE BUILDS INTO THE REGION FROM THE NORTH
THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM THURSDAY...5H S/W TROF TO MOVE ACROSS THE ILM CWA THIS
MORNING THROUGH MIDDAY. AT THE MOMENT ITS LIKELY AIDING THE
RE-FIRING OF THE LINE OF CONVECTION THAT NEARLY DISSIPATED EARLIER.
ONCE MAYS INSOLATION MAKES ITSELF KNOWN...WOULD EXPECT A FURTHER
DESTABILIZATION OF THE ATMOSPHERE I.E. THE NAM BUFR SOUNDINGS
INDICATE CAPE BETWEEN 2.4 TO 2.7K JUST SEVERAL HRS AFTER SUNRISE
ACROSS THE ILM CWA. IN ADDITION...ALTHOUGH WEAK...A SFC COLD/COOL
FRONT/BOUNDARY WILL ALSO BE IN THE VICINITY TO FURTHER AID TODAYS
CONVECTION. THERE4...FEEL COMFORTABLE WITH 50 POPS ACROSS THE
MAJORITY OF THE ILM CWA. IN ADDITION...THE SEVERITY OF THE
CONVECTION IS HIGHLIGHTED ONCE AGAIN ACROSS THE ILM CWA BY
SPC...WITH HAIL AND DAMAGING WIND GUSTS THE PRIMARY POTENTIALS. WILL
HOLD OFF FROM PLACING IN THE ACTUAL FORECASTS BUT HIGHLIGHT IN THE
HAZARDOUS WEATHER OUTLOOK. TODAYS MAX AND TONIGHTS MIN FCSTS LOOK
AOK WITH VERY LITTLE CHANGES NEEDED GIVEN LATEST VARIOUS MODEL MOS
GUIDANCE CONTINUING ITS CONSISTENCY FROM MODEL RUN TO RUN.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...FLAT PROGRESSIVE 5H PATTERN REMAINS IN
PLACE THROUGH THE PERIOD AND WILL KEEP STALLED SURFACE BOUNDARY
JUST NORTH OF THE AREA. WEAK SHORTWAVES PASSING NORTH OF THE AREA
MAY NOT BE CLOSE ENOUGH TO HAVE AN IMPACT ON THE AREA. EVEN IF A
WAVE WERE TO MOVE ACROSS THE AREA THERE IS A LOT OF DRY AIR AND A
CAP FROM 900 TO 800 MB THAT WOULD TEND TO SUPPRESS CONVECTION. SEA
BREEZE MIGHT BE ABLE TO PROVIDE ENOUGH LIFT TO OVER COME THE CAP
ON FRI...WHEN CAP IS A LITTLE WEAKER AND THERE IS A LITTLE MORE
MOISTURE AVAILABLE. WILL CARRY LOW CHANCE POP INLAND FRI WITH
SLIGHT CHANCE CLOSER TO THE COAST...WHICH IS PROBABLY ON THE
GENEROUS SIDE.
HOLDING ONTO SLIGHT CHANCE POPS FOR SAT FOR NOW BUT ITS LOOKING LESS
LIKELY. PRECIP HOPES WILL BE TIED TO PVA AHEAD OF SHORTWAVE SAT
NIGHT...AND THE GUIDANCE HAS BEEN FIGHTING FEEDBACK WHICH AFFECTS
TIMING AND STRENGTH OF THESE WAVES. TEMPERATURES WILL RUN 5 TO 10
DEGREES ABOVE CLIMO BOTH DAY AND NIGHT...WITH READINGS A LITTLE
CLOSER TO CLIMO NEARER TO THE COAST.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 3 AM THURSDAY...PROGRESSIVE FLAT 5H PATTERN CONTINUES
THROUGH MUCH OF THE PERIOD. SURFACE BOUNDARY THAT HAS BEEN STALLED
NORTHWEST OF THE AREA WILL START HAVING A DIRECT IMPACT ON THE
AREA LATER SUN AND CONTINUING THROUGH AT LEAST MON NIGHT. 12Z
ECMWF PUSHES THE FRONT SOUTH OF THE AREA TUE AS HIGH PRESSURE
BUILDS IN FROM THE NORTH. THE 00Z GFS IS IN SOMEWHAT GOOD
AGREEMENT WITH THIS TIMING...THOUGH IT SHOULD BE NOTED THAT EVERY
24 HOURS IT SEEMS FROPA IS AGAIN BEING DELAYED.
PRECIP CHANCES WILL MAINLY BE DEPENDANT ON TIMING OF SHORTWAVE
PASSAGE AND OTHER THAN A GENERAL TIME RANGE...SUN NIGHT AND AGAIN
MON AFTN...CANNOT GET TO PRECISE. ALSO EXPECT DIURNALLY DRIVEN
INSTABILITY AND THE SEA BREEZE TO PRODUCE SOME CONVECTION...BUT
COVERAGE WILL REMAIN LIMITED. TEMPERATURES SUN AND MON WILL BE NEAR
CLIMO...MAINLY DUE TO INCREASING CLOUD COVER THOUGH HEIGHTS DO DROP
A BIT ON MON AS SOUTHERN BRANCH OF JET STREAM SAGS SOUTH. IF LATEST
GFS AND 12Z ECMWF ARE TO BE BELIEVED...TUE AND WED WILL BE DRY WITH
TEMPERATURES BELOW CLIMO.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
A STATIONARY FRONT LOCATED ALONG THE VIRGINIA-NORTH CAROLINA
BORDER...EXTENDS SOUTHWEST TO NEAR KHKY. THE FRONT WILL CONTINUE TO
REMAIN NORTH OF THE TERMINALS THIS FORECAST PERIOD. THE BOUNDARY
FROM WHATS LEFT OF THE SQUALL LINE RESIDES NORTH-SOUTH...BASICALLY
ALONG AND IN THE VICINITY OF I-95. THIS WILL BE THE FOCUS FOR
CONVECTION THE REMAINDER OF THE NIGHT INTO DAYLIGHT THURSDAY.
DURING THURSDAY...ATMOSPHERIC CONDITIONS CONTINUE FOR A MODERATELY
UNSTABLE REGION WITH RIPPLES OF SHORT WAVE ENERGY MOVING WEST TO
EAST ACROSS THE AREA TERMINALS. TIMING OF THESE WAVES WILL BE KEY
IN THE TIME OF THE FORECAST OF THUNDERSTORMS. HAVE INCLUDED TEMPO
GROUPS TO ATLEAST TIME THE 1ST WAVE COMBINED WITH THE SFC
FEATURE...THE LEFTOVER BNDRY.
EXTENDED OUTLOOK THROUGH MONDAY...SCATTERED THUNDERSTORMS SUNDAY.
ISOLATED THUNDERSTORMS FRIDAY AND SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM THURSDAY...A DECENT SOUTHERLY FETCH WITH WIND SPEEDS
IN THE 15-20 KT RANGE IS EXPECTED TO FURTHER INCREASE CURRENT SEAS
TO SCA THRESHOLDS BY SUNRISE. AS A RESULT...DO NOT SEE A NEED TO
RE-VISIT THE TIMING OF THE START OF THE CURRENT SCA ACROSS THE 2
NORTHERN ZONES. THE SCEC FOR THE SOUTHERN 2 ZONES ALSO STILL LOOKS
ON TARGET. WAVEWATCH3 THIS TIME LOOKS AS IF IT MAY BE CATCHING UP TO
REALITY. OF NOTE...FOR THE PAST SEVERAL DAYS UNDER AN ONSHORE
SOUTHERLY COMPONENT WITHIN THE WIND FIELD...SSTS HAVE STEADILY
INCREASED TO THE LOWER 70S WITH SOME MID 70S BEING REPORTED. THIS
MARINE LAYER AT THE MOMENT REMAINS A HINDERANCE TO CONVECTION WHEN
ENCOUNTERING IT FROM THE WEST...HOWEVER IF SSTS CONTINUE THEIR
CURRENT UPWARD MOMENTUM...THE MARINE LAYER BEHIND THE SEA BREEZE
WILL NO LONGER BE THAT AUTOMATIC KILLER FOR CONVECTION THAT USUALLY
COMMENCES MID SUMMER.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...SOUTH TO SOUTHWEST FLOW WILL CONTINUE OVER THE
WATERS DURING THE PERIOD. GFS WIND SPEEDS HAVE CONSISTENTLY BEEN TO
HIGH...LIKELY DUE TO AIR/SEA INTERFACE ISSUES...SO FAVORING THE NAM
FOR SPEEDS. ISSUES WITH GFS WIND SPEEDS ALSO CAUSES WWIII GUIDANCE
TO BE ON THE HIGH SIDE. WILL KNOCK ABOUT A FOOT OFF WITH SLIGHT
TWEAKS DUE TO PROLONGED SOUTHERLY FETCH.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 AM THURSDAY...FRONT WILL BE IN THE AREA SUN AND MON MAKING
WIND DIRECTION FORECAST QUITE DIFFICULT. LUCKILY WITH THE FRONT
DRAPED ACROSS THE WATERS GRADEINT WILL BE VERY WEAK AND SPEEDS
WILL BE UNDER 10 KT BUT HIGHLY VARIABLE. EVENTUALLY WINDS WILL
DEVELOP A NORTHERLY COMPONENT BUT THAT MAY NOT OCCUR UNTIL AFTER
THE END OF THE FORECAST PERIOD. LEFT OVER SWELL FROM PROLONGED
PERIOD OF SOUTHERLY FETCH WILL KEEP SEAS RUNNING A LITTLE HIGHER
THAN SPEEDS WOULD SUGGEST. SEAS 3 TO 5 FT ON SUN SUBSIDING TO 2 TO
3 FT FOR MON.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT FRIDAY FOR AMZ250-252.
&&
$$
NEAR TERM...DCH
SHORT TERM...III
LONG TERM...III
AVIATION...DCH/HAWKINS
000
FXUS62 KMHX 070815
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
415 AM EDT THU MAY 7 2009
.SYNOPSIS...
HIGH PRESSURE WILL BE CENTERED IN THE WESTERN ATLANTIC THROUGH
SATURDAY. MEANWHILE A COLD FRONT EAST OF THE APPALACHIANS WILL
MOVE SLOWLY SOUTHEAST TODAY THEN DISSIPATE JUST NORTHWEST OF THE
AREA TONIGHT. A SECONDARY COLD FRONT WILL APPROACH FROM THE
NORTHWEST ON SATURDAY AND MOVE SLOWLY THROUGH THE AREA SATURDAY
NIGHT THROUGH SUNDAY. HIGH PRESSURE GRADUALLY BUILDS INTO THE AREA
FROM THE NORTH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY/...
CONVECTION BLOSSOMING EARLY THIS MORN NEAR I95 ALONG THE NC/SC
BORDER ASSOCD WITH A LEAD SHORTWAVE OUT AHEAD OF MAIN MID LVL
TROF. THIS PCPN WILL MOVE NE AND AFFECT MAINLY CSTL PLAIN THRU
SUNRISE. EXPECT THIS ACTIVITY TO PICK UP IN INTENSITY AS IT MOVES
INTO AREA OF MODEST INSTABILITY/LLJ EAST OF I95. WL NEED TO
MONITOR FOR SVR THREAT WITH DAMAGING WIND GUSTS BEING THE MAIN
THREAT FOR THE FIRST PART OF THE DAY.
THIS FIRST BATCH OF CONVECTION WILL BE MOVE NE AND ACRS OBX
DURING THE LATE MORN/EARLY AFTN. MID LVL FLOW TURNS WESTERLY WITH
AFTN SUBSIDENCE DOMINANT AFTER PASSAGE OF INITIAL SHORT WAVE. A
SECONDARY BAND OF CONVECTION MAY DEVELOP LATE THIS AFTN OR EARLY
EVE WITH MAIN SHORT WAVE. ANY ASSOCD PCPN LOOKS TO BE MOVING OFF
OBX BY EARLY MORN.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
RELATIVELY BENIGN WEATHER STARTS OUT THIS FCST PERIOD WITH ONLY
WEAK PERTURBATIONS IN THE FLAT MID LVL FLOW TO GENERATE ORGANIZED
CONVECTION. COULD STILL SEE ISOLD/SCTD CONVECTION FIRING ON ANY
LOCALIZED BNDRYS MAINLY DURING PEAK HEAT CYCLES. AN INCREASED CHC
OF SCTD CONVECTION AS A BETTER DEFINED SHORT WAVE TROF APPROACHES
SAT AFTN.
HIGH TEMPS THIS FCST PERIOD WELL INTO THE 80S AND MAY APPROACH
90F INLAND GIVEN THE INCREASED SUNSHINE...LOW LVL THICKNESS
VALUES AND DOWNSLOPE FLOW.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
INCOMING COLD FRONT WILL SLOW DOWN AS IT MOVES INTO THE AREA
DURING THE SECOND HALF OF THE WEEKEND. EVEN IF FRONT PUSHES ALL
THE WAY THROUGH WILL LIKELY SEE PERIODS OF CLOUDS AND SCTD PCPN
OVERRIDING THE FRONT TO THE SOUTH INTO MON/MON NIGHT. EAST COAST
TROF GRADUALLY SHARPENS EARLY NEXT WEEK AND THE VEERING STEERING
FLOW WILL EVENTUALLY SHOVE THE STALLED SFC BNDRY FARTHER DOWN THE
SE COAST WHICH WILL LEAD TO DRIER/COOLER CONDS ACRS THE FCST AREA
THRU MIDWEEK.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
SOME MVFR CIGS EXPECTED TO DEVELOP EARLY THIS MORN ESPECIALLY
OVER THE KPGV AND KISO TERMINALS. CIGS EXPECTED TO LIFT TO VFR AFT
14Z BUT SHRA/TS EXPECTED TO INCREASE THU MORNING AS A DECENT SHORT
WAVE APPROACHES. PREVAILING VFR EXPECTED ALL TERMINALS THU BUT
PERIODS OF MAINLY MVFR CONDITIONS EXPECTED WITH ANY CONVECTION.
PREDOMINANT VFR EXPECTED THIS WEEKEND OUTSIDE OF ANY DIURNAL
CONVECTION THAT WILL BE POSSIBLE. A COLD FRONT WILL MOVE
ACROSS THE TERMINALS ON SUN WITH SHRA/TS ENDING.
&&
.MARINE...
LATEST MODEL GUIDANCE SHOW WINDS INCREASING TODAY WITH SEAS
BUILDING TO 5 TO 7 FT. THE GFS IS MUCH STRONGER WITH THE SW FLOW
COMPARED TO THE OTHER SHORT RANGE GUIDANCE. OPC NOT FAVORING THE
GFS IN THE SHORT TERM AND CURRENT WIND SPEEDS MAY BE TOO HIGH OVER
OUR WATERS FOR THU. HAVE OPTED TO KEEP HEADLINES AS IS FOR NOW AND
LET THE MID SHIFT TAKE A LOOK AT THE LATEST GUIDANCE TO DETERMINE
IF/WHERE ADJUSTMENTS TO ANY HEADLINES WILL BE NEEDED.
A QUASI- STATIONARY FRONT WILL REMAIN JUST TO THE WEST OF THE
WATERS THROUGH SUNDAY. SEVERAL SHORTWAVE TROUGHS WILL INTERACT
WITH THE BOUNDARY PRODUCING WEAK FRONTAL WAVES WHICH WILL ENHANCE
THE SW FLOW AND PRODUCE WINDS AROUND 25 KT AND SEAS 6-8 FT. THE
FRONT IS EXPECTED TO FINALLY SINK SOUTH OF THE WATERS SUNDAY
EVENING WITH THE FLOW TURNING TO NE. THE NEW GFS AND ECMWF ARE
STRONGER WITH THE POST FRONTAL NE FLOW (20 KT) INDICATING A
CONTINUATION OF ADVISORY OF NEAR ADVISORY CONDITIONS FROM CAPE
LOOKOUT TO OREGON INLET. THE EXTREME NORTHERN AND SOUTHERN WATERS
MAY IMPROVE BELOW ADVISORY CRITERIA MONDAY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR AMZ130-
135.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT SUNDAY FOR AMZ152-154-156-
158.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR AMZ150.
&&
$$
SYNOPSIS...BTC
NEAR TERM...BTC
SHORT TERM...BTC
LONG TERM...BTC
AVIATION...JME/JW
MARINE...JME/JW
000
FXUS62 KRAH 070743
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
330 AM EDT THU MAY 7 2009
.SYNOPSIS...
A STRONG UPPER LEVEL DISTURBANCE WILL PIVOT ACROSS THE AREA BY
MIDDAY...BRINGING ANOTHER ROUND SHOWERS AND THUNDERSTORMS ACROSS
CENTRAL NORTH CAROLINA THROUGH THE AFTERNOON. A WEAK SURFACE TROUGH
WILL THEN LINGER ACROSS THE CAROLINAS THROUGH SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM THURSDAY...
THE BROKEN CONVECTIVE LINE CURRENTLY MOVING THROUGH THE CENTRAL
PIEDMONT IS ASSOCIATED WITH THE 50KT LOW-LEVEL JET BUT IS REALLY
HAVING A HARD TIME BECOMING ORGANIZED AS BOUNDARY LAYER CIN HAS
REALLY DETERRED THE UPDRAFT STRENGTH. HOWEVER...WE STILL HAVE THE
BETTER UPPER DYNAMICS UPSTREAM...AS THE POTENT MID AND UPPER LEVEL
TROUGH OVER EASTERN TN PIVOTS ACROSS CENTRAL NC BETWEEN 09 TO 15Z.
THE COLD CORE ALOFT WILL BRING STEEP MID-LEVEL LAPSE RATES THROUGH
THE INTERSTATE 77 CORRIDOR...NEAR BOONE...AND UP INTO BLACKSBURG VA
WITH STRONG UPPER DIVERGENCE OVERSPREADING ENTIRE THE AREA AS RIGHT
ENTRANCE REGION OF UPPER JET TRAVERSES THE AREA. GIVEN THE HIGH PWAT
AIRMASS...THIS SHOULD ALLOW FOR WIDESPREAD COVERAGE THROUGH THE RUSH
HOUR MORNING COMMUTE...WITH THE POTENTIAL FOR THE STORMS TO BECOME
BETTER ORGANIZE/STRENGTHEN AS IT ENCOUNTERS THE MORE UNSTABLE AIRMASS
RESIDING IN THE COASTAL PLAIN...PER LATEST SPC MESOANALYSIS OF 500
TO 1000 J/KG IN THE AREA.
THIS AREA OF CONVECTION IS EXPECTED TO PUSH EAST OF THE AREA BY 15
TO 16Z...AS THE SURFACE TROUGH STALLS OUT ACROSS THE WESTERN
PIEDMONT. INCREASING WESTERLY FLOW ALOFT...BEHIND THE UPPER WAVE
WILL RESULT IN A SCATTERING OUT OF THE BROKEN CLOUD
COVER...RESULTING IN DECENT SURFACE HEATING WITH TEMPERATURES
CLIMBING INTO THE LOWER TO MID 80S. WITH AFTERNOON LOW-LEVEL LAPSE
RATES STEEPENING AOA 8.5 C/KM WITH PWATS STILL AROUND 1.1 TO
1.2"...CONVECTION IS EXPECTED TO RE-DEVELOP THIS AFTERNOON WITH BOTH
THE NAM AND GFS SHOWING SUBTLE S/W IMPULSES IN THE WESTERLY FLOW
ALOFT. MODERATE INSTABILITY OF 1500 TO 2000 J/KG WITH 30 TO 40 KTS
OF BULK SHEAR WILL SUPPORT STRONG TO SEVERE STORMS WITH PRECIP
LOADING BRINGING A THREAT OF WET MICROBURSTS...AND LOWERING WET-BULB
ZEROS OF 8.5-9.0 KFT BRINGING A THREAT OF LARGE HAIL. THE CONVECTION
WILL BE LARGELY DIURNALLY DRIVEN AND SHOULD QUICKLY DIMINISH SHORTLY
AFTER SUNSET. UNDER PARTLY CLOUDY SKIES AND A LIGHT
WEST-SOUTHWESTERLY WIND FLOW... OVERNIGHT LOWS WILL COOL INTO THE
LOWER TO MID 60S.
.
&&
.SHORT TERM /FRIDAY/...
AS OF 325 AM THURSDAY...
THICKNESSES INCREASE AOA 1410 TO 1415 FRIDAY AFTERNOON SUPPORTING
AFTERNOON HIGHS OF 85 TO 90 ACROSS THE AREA. THE STRONG SURFACE
HEATING WILL SUPPORT A MODERATELY UNSTABLE AIRMASS AS
PIEDMONT SURFACE TROUGH RESIDES IN THE LEE OF THE APPALACHIANS WITH
PWATS INCREASING TO 1.3 TO 1.4". WHILE UPPER JET CORE WILL BE WELL
NORTH OF THE AREA ACROSS OHIO VALLEY AND MID ATLANTIC STATES...S/W
VORTS...POSSIBLY CONVECTIVELY INDUCED IN NATURE IS PROGGED BY BOTH
THE GFS AND NAM TO SPREAD EAST ACROSS THE AREA FRIDAY
AFTERNOON...WITH 40 TO 50KTS OF WEST-NORTHWEST DEEP LAYER SHEAR.
FOR NOW WILL GO WITH SCATTERED...30 TO 40 PERCENT POP WITH A SLIGHT
RISK OF SEVERE STORMS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
AS OF 330 AM THURSDAY...
A DIFFICULT PRECIP FORECAST FOR FRIDAY NIGHT AS IT IS TOUGH TO
ASCERTAIN THE DEVELOPMENT AND EVOLUTION OF ANY MCVS TO OUR WEST THAT
COULD APPROACH THE AREA OVERNIGHT. THE GFS IS THE STRONGEST WITH
SUCH A SHORTWAVE...GENERATING A RATHER ROBUST SFC LOW JUST NORTH OF
THE VA/NC BORDER. THE ECMWF/NAM ARE WEAKER AND FURTHER NORTH WITH
THIS ACTIVITY. IF A MCV DOES TRACK ACROSS THE REGION...IT WOULD
ENCOUNTER ENOUGH LINGERING INSTABILITY (500-800 J/KG MUCAPE) WITH
DEWPOINTS IN THE MID 60S TO PRODUCE SCATTERED CONVECTION. WILL KEEP
POPS ON THE LOW SIDE AND HIGHEST (30%) IN THE FAR NORTH DUE TO THE
UNCERTAINTY. LOWS A VERY MILD AND MUGGY 64-68.
A COLD FRONT WILL BEGIN TO APPROACH FROM THE NORTHWEST BY LATE
SATURDAY AFTERNOON AS A MID LEVEL TROUGH OVER THE GREAT LAKES
BEGINS TO MOVE EAST TOWARD NEW ENGLAND. EXPECT SCATTERED SHOWERS AND
THUNDERSTORMS TO DEVELOP ALONG AND AHEAD OF THE FRONT AS IT
ENCOUNTERS AN UNSTABLE AIRMASS REPRESENTED WITH MLCAPES ABOVE 1000
J/KG. THE BEST MID LEVEL FORCING STAYS WELL TO OUR NORTH...SO WILL
KEEP POPS IN THE CHANCE CATEGORY. THICKNESSES SOAR INTO THE
1410-1420M RANGE...SUPPORTING UPPER 80S TO LOWER 90S FOR HIGHS. THE
FRONT MOVES THROUGH SATURDAY NIGHT WITH A CONTINUED CHANCE FOR
SCATTERED CONVECTION...BUT AS INSTABILITY WANES OVERNIGHT AND THE
LACK OF ANY LARGE SCALE FORCING...PRECIP CHANCES WILL GRADUALLY
DIMINISH. LOWS 60-67.
GUIDANCE IS COMING INTO BETTER AGREEMENT ON STALLING THE COLD FRONT
JUST TO THE SOUTH OF THE CWA SUNDAY AND MONDAY WITH THE 850 MB FRONT
STALLING OVERHEAD. AS SUBTLE PIECES OF ENERGY MOVE THROUGH THE ZONAL
FLOW ALOFT...PERIODS OF OVERRUNNING PRECIPITATION WILL BE POSSIBLE.
RAIN CHANCES LOOK TO TAPER OFF BY TUESDAY MORNING AS A STRONGER
SHORTWAVE OVER THE NORTH CENTRAL STATES DIVES SOUTHEAST INTO THE MID
ATLANTIC AND PUSHES THE FRONT FURTHER SOUTH AND EAST. TEMPS THROUGH
THIS PERIOD WILL RETURN TO MORE SEASONABLE LEVELS...DUE TO THE
COMBINATION OF COOL HIGH PRESSURE BUILDING IN ALONG WITH INCREASED
CLOUD COVER PARTICULARLY ON SUNDAY/MONDAY. HIGHS GENERALLY IN THE
70S AND LOWS IN THE 50S.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 145 AM THURSDAY...
A LINE OF CONVECTION WILL MOVE FROM RDU EAST OVER THE NEXT COUPLE OF
HOURS BRINGING A BRIEF PERIOD OF MVFR CONDITIONS IN THE HEAVY RAIN
SHOWERS AND ISOLATED STRONG WIND GUSTS. WILL HAVE TO BE ON THE
LOOKOUT FOR A SECOND AREA OF SHOWERS AND THUNDERSTORMS CURRENTLY
RACING EAST ACROSS THE SOUTHERN APPALACHIANS...WHICH WILL BRING
ANOTHER 2 TO 3 HOUR PERIOD OF MVFR CONDITIONS...ESPECIALLY FROM RDU
EAST...AS THE STORMS ENTER IN AN AREA OF BETTER INSTABILITY. MODELS
BRING THIS SECOND AREA OF CONVECTION ACROSS THE EASTERN HALF OF 15Z.
CEILINGS SHOULD SCATTER OUT TO VFR BY LATE MORNING...AND THEN BECOME
BROKEN AGAIN AS STRONG AFTERNOON HEATING WILL ALLOW FOR CONVECTION
TO DEVELOP ALONG A WEAK SURFACE TROUGH LOCATED ACROSS THE WESTERN
PIEDMONT. LOSS OF DAYTIME HEATING SHOULD GREATLY DIMINISH CONVECTIVE
ACTIVITY WITH SCATTERED VFR CEILINGS OVERNIGHT.
UNSETTLED WEATHER EXPECTED FRIDAY NIGHT THROUGH MONDAY AS A COLD
FRONT APPROACHES THEN STALLS IN OUR VICINITY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...CBL
SHORT TERM...CBL
LONG TERM...JFB
AVIATION...CBL
000
FXUS62 KRAH 070732
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
145 AM EDT THU MAY 7 2009
.SYNOPSIS...
A STRONG UPPER LEVEL DISTURBANCE WILL PIVOT ACROSS THE AREA BY
MIDDAY...BRINGING ANOTHER ROUND SHOWERS AND THUNDERSTORMS ACROSS
CENTRAL NORTH CAROLINA THROUGH THE AFTERNOON. A WEAK SURFACE TROUGH
WILL THEN LINGER ACROSS THE CAROLINAS THROUGH SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM THURSDAY...
THE BROKEN CONVECTIVE LINE CURRENTLY MOVING THROUGH THE CENTRAL
PIEDMONT IS ASSOCIATED WITH THE 50KT LOW-LEVEL JET BUT IS REALLY
HAVING A HARD TIME BECOMING ORGANIZED AS BOUNDARY LAYER CIN HAS
REALLY DETERRED THE UPDRAFT STRENGTH. HOWEVER...WE STILL HAVE THE
BETTER UPPER DYNAMICS UPSTREAM...AS THE POTENT MID AND UPPER LEVEL
TROUGH OVER EASTERN TN PIVOTS ACROSS CENTRAL NC BETWEEN 09 TO 15Z.
THE COLD CORE ALOFT WILL BRING STEEP MID-LEVEL LAPSE RATES THROUGH
THE INTERSTATE 77 CORRIDOR...NEAR BOONE...AND UP INTO BLACKSBURG VA
WITH STRONG UPPER DIVERGENCE OVERSPREADING ENTIRE THE AREA AS RIGHT
ENTRANCE REGION OF UPPER JET TRAVERSES THE AREA. GIVEN THE HIGH PWAT
AIRMASS...THIS SHOULD ALLOW FOR WIDESPREAD COVERAGE THROUGH THE RUSH
HOUR MORNING COMMUTE...WITH THE POTENTIAL FOR THE STORMS TO BECOME
BETTER ORGANIZE/STRENGTHEN AS IT ENCOUNTERS THE MORE UNSTABLE AIRMASS
RESIDING IN THE COASTAL PLAIN...PER LATEST SPC MESOANALYSIS OF 500
TO 1000 J/KG IN THE AREA.
THIS AREA OF CONVECTION IS EXPECTED TO PUSH EAST OF THE AREA BY 15
TO 16Z...AS THE SURFACE TROUGH STALLS OUT ACROSS THE WESTERN
PIEDMONT. INCREASING WESTERLY FLOW ALOFT...BEHIND THE UPPER WAVE
WILL RESULT IN A SCATTERING OUT OF THE BROKEN CLOUD
COVER...RESULTING IN DECENT SURFACE HEATING WITH TEMPERATURES
CLIMBING INTO THE LOWER TO MID 80S. WITH AFTERNOON LOW-LEVEL LAPSE
RATES STEEPENING AOA 8.5 C/KM WITH PWATS STILL AROUND 1.1 TO
1.2"...CONVECTION IS EXPECTED TO RE-DEVELOP THIS AFTERNOON WITH BOTH
THE NAM AND GFS SHOWING SUBTLE S/W IMPULSES IN THE WESTERLY FLOW
ALOFT. MODERATE INSTABILITY OF 1500 TO 2000 J/KG WITH 30 TO 40 KTS
OF BULK SHEAR WILL SUPPORT STRONG TO SEVERE STORMS WITH PRECIP
LOADING BRINGING A THREAT OF WET MICROBURSTS...AND LOWERING WET-BULB
ZEROS OF 8.5-9.0 KFT BRINGING A THREAT OF LARGE HAIL. THE CONVECTION
WILL BE LARGELY DIURNALLY DRIVEN AND SHOULD QUICKLY DIMINISH SHORTLY
AFTER SUNSET. UNDER PARTLY CLOUDY SKIES AND A LIGHT
WEST-SOUTHWESTERLY WIND FLOW... OVERNIGHT LOWS WILL COOL INTO THE
LOWER TO MID 60S.
.
&&
.SHORT TERM /FRIDAY/...
AS OF 325 AM THURSDAY...
THICKNESSES INCREASE AOA 1410 TO 1415 FRIDAY AFTERNOON SUPPORTING
AFTERNOON HIGHS OF 85 TO 90 ACROSS THE AREA. THE STRONG SURFACE
HEATING WILL SUPPORT A MODERATELY UNSTABLE AIRMASS AS
PIEDMONT SURFACE TROUGH RESIDES IN THE LEE OF THE APPALACHIANS WITH
PWATS INCREASING TO 1.3 TO 1.4". WHILE UPPER JET CORE WILL BE WELL
NORTH OF THE AREA ACROSS OHIO VALLEY AND MID ATLANTIC STATES...S/W
VORTS...POSSIBLY CONVECTIVELY INDUCED IN NATURE IS PROGGED BY BOTH
THE GFS AND NAM TO SPREAD EAST ACROSS THE AREA FRIDAY
AFTERNOON...WITH 40 TO 50KTS OF WEST-NORTHWEST DEEP LAYER SHEAR.
FOR NOW WILL GO WITH SCATTERED...30 TO 40 PERCENT POP WITH A SLIGHT
RISK OF SEVERE STORMS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
AS OF 330 AM THURSDAY...
A DIFFICULT PRECIP FORECAST FOR FRIDAY NIGHT AS IT IS TOUGH TO
ASCERTAIN THE DEVELOPMENT AND EVOLUTION OF ANY MCVS TO OUR WEST THAT
COULD APPROACH THE AREA OVERNIGHT. THE GFS IS THE STRONGEST WITH
SUCH A SHORTWAVE...GENERATING A RATHER ROBUST SFC LOW JUST NORTH OF
THE VA/NC BORDER. THE ECMWF/NAM ARE WEAKER AND FURTHER NORTH WITH
THIS ACTIVITY. IF A MCV DOES TRACK ACROSS THE REGION...IT WOULD
ENCOUNTER ENOUGH LINGERING INSTABILITY (500-800 J/KG MUCAPE) WITH
DEWPOINTS IN THE MID 60S TO PRODUCE SCATTERED CONVECTION. WILL KEEP
POPS ON THE LOW SIDE AND HIGHEST (30%) IN THE FAR NORTH DUE TO THE
UNCERTAINTY. LOWS A VERY MILD AND MUGGY 64-68.
A COLD FRONT WILL BEGIN TO APPROACH FROM THE NORTHWEST BY LATE
SATURDAY AFTERNOON AS A MID LEVEL TROUGH OVER THE GREAT LAKES
BEGINS TO MOVE EAST TOWARD NEW ENGLAND. EXPECT SCATTERED SHOWERS AND
THUNDERSTORMS TO DEVELOP ALONG AND AHEAD OF THE FRONT AS IT
ENCOUNTERS AN UNSTABLE AIRMASS REPRESENTED WITH MLCAPES ABOVE 1000
J/KG. THE BEST MID LEVEL FORCING STAYS WELL TO OUR NORTH...SO WILL
KEEP POPS IN THE CHANCE CATEGORY. THICKNESSES SOAR INTO THE
1410-1420M RANGE...SUPPORTING UPPER 80S TO LOWER 90S FOR HIGHS. THE
FRONT MOVES THROUGH SATURDAY NIGHT WITH A CONTINUED CHANCE FOR
SCATTERED CONVECTION...BUT AS INSTABILITY WANES OVERNIGHT AND THE
LACK OF ANY LARGE SCALE FORCING...PRECIP CHANCES WILL GRADUALLY
DIMINISH. LOWS 60-67.
GUIDANCE IS COMING INTO BETTER AGREEMENT ON STALLING THE COLD FRONT
JUST TO THE SOUTH OF THE CWA SUNDAY AND MONDAY WITH THE 850 MB FRONT
STALLING OVERHEAD. AS SUBTLE PIECES OF ENERGY MOVE THROUGH THE ZONAL
FLOW ALOFT...PERIODS OF OVERRUNNING PRECIPITATION WILL BE POSSIBLE.
RAIN CHANCES LOOK TO TAPER OFF BY TUESDAY MORNING AS A STRONGER
SHORTWAVE OVER THE NORTH CENTRAL STATES DIVES SOUTHEAST INTO THE MID
ATLANTIC AND PUSHES THE FRONT FURTHER SOUTH AND EAST. TEMPS THROUGH
THIS PERIOD WILL RETURN TO MORE SEASONABLE LEVELS...DUE TO THE
COMBINATION OF COOL HIGH PRESSURE BUILDING IN ALONG WITH INCREASED
CLOUD COVER PARTICULARLY ON SUNDAY/MONDAY. HIGHS GENERALLY IN THE
70S AND LOWS IN THE 50S.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 145 AM THURSDAY...
A LINE OF CONVECTION WILL MOVE FROM RDU EAST OVER THE NEXT COUPLE OF
HOURS BRINGING A BRIEF PERIOD OF MVFR CONDITIONS IN THE HEAVY RAIN
SHOWERS AND ISOLATED STRONG WIND GUSTS. WILL HAVE TO BE ON THE
LOOKOUT FOR A SECOND AREA OF SHOWERS AND THUNDERSTORMS CURRENTLY
RACING EAST ACROSS THE SOUTHERN APPALACHIANS...WHICH WILL BRING
ANOTHER 2 TO 3 HOUR PERIOD OF MVFR CONDITIONS...ESPECIALLY FROM RDU
EAST...AS THE STORMS ENTER IN AN AREA OF BETTER INSTABILITY. MODELS
BRING THIS SECOND AREA OF CONVECTION ACROSS THE EASTERN HALF OF 15Z.
CEILINGS SHOULD SCATTER OUT TO VFR BY LATE MORNING...AND THEN BECOME
BROKEN AGAIN AS STRONG AFTERNOON HEATING WILL ALLOW FOR CONVECTION
TO DEVELOP ALONG A WEAK SURFACE TROUGH LOCATED ACROSS THE WESTERN
PIEDMONT. LOSS OF DAYTIME HEATING SHOULD GREATLY DIMINISH CONVECTIVE
ACTIVITY WITH SCATTERED VFR CEILINGS OVERNIGHT.
UNSETTLED WEATHER EXPECTED FRIDAY NIGHT THROUGH MONDAY AS A COLD
FRONT APPROACHES THEN STALLS IN OUR VICINITY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...CBL
SHORT TERM...CBL
LONG TERM...JFB
AVIATION...CBL
000
FXUS62 KRAH 070647
AFDRAH
AREA FORECAST DISCUSSION...UPDATED.
NATIONAL WEATHER SERVICE RALEIGH NC
245 AM EDT THU MAY 7 2009
.SYNOPSIS...
A STRONG UPPER LEVEL DISTURBANCE WILL PIVOT ACROSS THE AREA BY
MIDDAY...BRINGING ANOTHER ROUND SHOWERS AND THUNDERSTORMS ACROSS
CENTRAL NORTH CAROLINA THROUGH THE AFTERNOON. A WEAK SURFACE TROUGH
WILL THEN LINGER ACROSS THE CAROLINAS THROUGH SATURDAY.
&&
.NEAR TERM /UNTIL 7 AM THURSDAY MORNING/...
AS OF 245 AM THURSDAY...
...HAVE CANCELLED NW PIEDMONT COUNTIES FROM TOR WATCH #257...
...THE WATCH WILL REMAIN IN EFFECT ELSEWHERE UNTIL 400 AM... THOUGH
SVR THREAT RELATIVELY LOW THROUGH WATCH EXPIRATION...
MOST ROBUST CONVECTION THE LAST FEW HOURS HAS BEEN OVER CENTRAL AND
EASTERN VA WHERE INSTABILITY AND FORCING ATTENDANT LEAD S/W TROUGH
AND LOW LEVEL FRONTAL CIRCULATION HAVE BEEN MAXIMIZED. FORCING FOR
ASCENT AHEAD OF A MUCH MORE VIGOROUS S/W TROUGH ALOFT/TROPOPAUSE
DISTURBANCE AND ATTENDANT SPEED MAX/COLD POOL ALOFT OVER THE TN
VALLEY/DEEP SOUTH THIS MORNING WILL CONTINUE TO SPREAD EASTWARD
THROUGH THE EARLY THURSDAY. THUS... EXPECT POSSIBLE INTENSIFICATION
OF UPSTREAM CONVECTION OR NORTHWARD INITIATION OF NEW... WITHIN
CONFLUENCE AXIS OVER WESTERN NC/SC PIEDMONTS/FOOTHILLS AND WESTERN
PERIPHERY OF HIGH THETA-E AIR TO THE EAST BETWEEN 09-12Z. MAIN
LIMITING FACTORS FOR A MORE SUBSTANTIAL SEVERE THREAT AT THAT TIME
WILL BE 1) THE CURRENT OVERHEAD LLJ AXIS AND ASSOCIATED STRONG LOW
LEVEL SHEAR WILL HAVE LIFTED NE/WRD BY THE TIME THE STRONGEST UVV/S
WITH THE APPROACHING TROUGH OVERSPREAD THE REGION AND 2) THE BEST
MID LEVEL COOLING AND DCVA ATTENDANT THE TROUGH SHOULD REMAIN OVER
MORE DIABATICALLY COOLED LOW LEVELS OVER NW NC AND SW/SOUTH CENTRAL
VA. -MWS
&&
.SHORT TERM /7 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
AS OF 310 PM WEDNESDAY...
EXPECT ONGOING CONVECTION EAST OF HIGHWAY 1 TO EXIT REGION AFTER
15Z. APPEARS THAT AIR MASS WILL BE ABLE TO RECOVER AND SUPPORT
SCATTERED STRONG CONVECTION AFTER 19Z OVER ALL BUT THE FAR NW.
EXPECT CLOUDS EARLY THU TO SCATTERED OUT BY LATE MORNING...ENABLING
TEMPS TO SOAR TO NEAR 80/LOWER 80S BY EARLY AFTERNOON. WHILE LOW
LEVEL AIRMASS WILL BE QUITE UNSTABLE...WIND FIELD ALOFT AND MID
LEVEL LAPSE RATES SUGGEST THAT SEVERE STORMS SHOULD BE FEW IN NUMBER
AND CONSISTENT OF LARGE HAIL AND DAMAGING WIND GUSTS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
AS OF 340 PM WEDNESDAY...
A SURFACE BOUNDARY MOVING EAST THROUGH CENTRAL NORTH CAROLINA
THURSDAY NIGHT INTO EARLY FRIDAY MORNING WILL TAKE THE CHANCE FOR
RAIN WITH IT. LOWS THURSDAY NIGHT WILL BE IN THE LOW TO MID 60S.
HIGHS FRIDAY WILL BE IN THE 80S.
THE BREAK IN THE RAIN WILL BE SHORT LIVED AS UNSETTLED WEATHER WILL
TAKE OVER IN RESPONSE TO A SERIES OF SURFACE WAVES IN CONJUNCTION
WITH UPPER LEVEL DISTURBANCES MOVING THROUGH WESTERLY FLOW ALOFT
FRIDAY NIGHT THROUGH MONDAY NIGHT. PWAT VALUES THROUGH THIS PERIOD
WILL BE IN EXCESS OF ONE INCH. LOWS FRIDAY AND SATURDAY NIGHT WILL
BE IN THE 60S... COOLING TO THE 50S FOR THE FIRST OF NEXT WEEK.
HIGHS SATURDAY IN THE 80S WILL DROP TO THE 70S BY MONDAY.
HIGH PRESSURE WILL BUILD OVER CENTRAL NORTH CAROLINA FROM THE
NORTHWEST TUESDAY INTO WEDNESDAY. HIGHS TUESDAY AND WEDNESDAY WILL
BE IN THE 70S. LOWS TUESDAY NIGHT WILL BE IN THE 50S.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 145 AM THURSDAY...
A LINE OF CONVECTION WILL MOVE FROM RDU EAST OVER THE NEXT COUPLE OF
HOURS BRINGING A BRIEF PERIOD OF MVFR CONDITIONS IN THE HEAVY RAIN
SHOWERS AND ISOLATED STRONG WIND GUSTS. WILL HAVE TO BE ON THE
LOOKOUT FOR A SECOND AREA OF SHOWERS AND THUNDERSTORMS CURRENTLY
RACING EAST ACROSS THE SOUTHERN APPALACHIANS...WHICH WILL BRING
ANOTHER 2 TO 3 HOUR PERIOD OF MVFR CONDITIONS...ESPECIALLY FROM RDU
EAST...AS THE STORMS ENTER IN AN AREA OF BETTER INSTABILITY. MODELS
BRING THIS SECOND AREA OF CONVECTION ACROSS THE EASTERN HALF OF 15Z.
CEILINGS SHOULD SCATTER OUT TO VFR BY LATE MORNING...AND THEN BECOME
BROKEN AGAIN AS STRONG AFTERNOON HEATING WILL ALLOW FOR CONVECTION
TO DEVELOP ALONG A WEAK SURFACE TROUGH LOCATED ACROSS THE WESTERN
PIEDMONT. LOSS OF DAYTIME HEATING SHOULD GREATLY DIMINISH CONVECTIVE
ACTIVITY WITH SCATTERED VFR CEILINGS OVERNIGHT.
UNSETTLED WEATHER EXPECTED FRIDAY NIGHT THROUGH MONDAY AS A COLD
FRONT APPROACHES THEN STALLS IN OUR VICINITY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...MWS
SHORT TERM...BL
LONG TERM...BADGETT/RHJ
AVIATION...RHJ
000
FXUS62 KILM 070604
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
200 AM EDT THU MAY 7 2009
.SYNOPSIS...
A LOW TO MID LEVEL TROUGH APPROACHING THE EASTERN CAROLINAS TONIGHT
WILL PASS OVERHEAD THURSDAY PRODUCING SHOWER AND THUNDERSTORM
ACTIVITY. WARMER AND DRIER WEATHER WILL PREVAIL ON FRIDAY AND
SATURDAY AS HIGH PRESSURE NOSES IN FROM THE WEST. A COLD FRONT WILL
MOVE ACROSS THE AREA SATURDAY NIGHT AND SUNDAY MORNING BRINGING
DRIER AIR FOR THE EARLY PART OF NEXT WEEK...AS HIGH PRESSURE BUILDS
INTO THE REGION FROM THE NORTH THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 9 PM WEDNESDAY...THE SQUALL LINE THAT PROMPTED NUMEROUS
WARNINGS ACROSS GEORGIA AND THE WESTERN CAROLINAS EARLIER TODAY IS
DYING AS IT MOVES OUT AHEAD OF ITS UPPER LEVEL SUPPORT. THE
RESIDUAL LINE OF SPRINKLES WILL BE IN THE PEE DEE REGION BY 10-11
PM. THE UPPER LEVEL TROUGH CURRENTLY OVER NW GA/TN WILL SHIFT EAST
AFTER MIDNIGHT AND WILL BRING THE EASTERN CAROLINAS INTO AN
INCREASINGLY FAVORABLE ENVIRONMENT FOR NEW CONVECTION TO DEVELOP
DESPITE THE UNFAVORABLE TIME OF DAY. FORECAST SOUNDINGS FROM THE NAM
AND GFS SHOW ELEVATED INSTABILITY ROOTED IN THE 950/925 MB LAYER
COULD SUSTAIN HEALTHY (ALTHOUGH PERHAPS NOT SEVERE) THUNDERSTORMS...
ESPECIALLY AFTER 2-3 AM. THE BEST CHANCE APPEARS TO BE IN THE
BENNETTSVILLE/LUMBERTON AREA INITIALLY...THEN SHIFTING THROUGH
ELIZABETHTOWN AND WHITEVILLE BY 4-5 AM AND TO THE CAPE FEAR COAST BY
DAYBREAK. A 35-KNOT LOW LEVEL JET AT 925 MB WILL PROVIDE A STEADY
SOURCE OF WARM MOIST AIR NORTHWARD.
WITH THE LOW LEVEL JET KEEPING SURFACE WINDS IN THE 8-15 MPH RANGE
OVERNIGHT...LOW TEMPERATURES WILL CONTINUE TO RUN QUITE MILD FOR THE
TIME OF YEAR. WE ARE EXPECTING LOWS NEAR 70 ALONG THE COAST WITH
UPPER 60S INLAND. IF SUSTAINED HEAVY CONVECTION CAN OCCUR (NOT
REALLY EXPECTED AT THIS TIME) TEMPERATURES COULD BOTTOM OUT A FEW
DEGREES COOLER IN SPOTS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...A FAIRLY DECENT SHORTWAVE WILL MOVE THROUGH
ON THURS WITH A RELATIVELY ZONAL FLOW TO FOLLOW AND A LESS
IMPRESSIVE RIPPLE IN THE FLOW LATE FRI. THIS SHORTWAVE WILL
TRANSLATE DOWN THROUGH THE LOWER LEVELS WITH TROUGH MOVING THROUGH
THURS AFTN. EXPECT MOST SHWR/TSTM ACTIVITY TO OCCUR MORE TOWARD
THE BEGINNING OF THE PERIOD AS SHORTWAVE TRAVERSES THE AREA AND
SHOULD TAPER OFF BY THURS EVENING FROM WEST TO EAST. ONCE
SHORTWAVE AND ASSOCIATED LOWER LEVEL TROUGH PASSES ON THURS GFS
SHOWS A NICE DRY PUNCH MOVING IN AS WINDS THROUGH THE LOWER TO MID
LEVELS SHIFT AROUND TO THE W-NW AND WILL MAINTAIN A WESTERLY
COMPONENT THROUGH THE REMAINDER OF THE PERIOD. BY FRI ANY SHOWER
ACTIVITY WILL BE FOCUSED ALONG SEA BREEZE IN THE AFTN AS IT PUSHES
INLAND. THURS WILL DEFINITELY BE THE MORE ACTIVE DAY WITH GFS/NAM
AND SREF SHOWING BEST CHC OF PCP AROUND 12 TO 18Z. MU CAPE WILL BE
UP TO AROUND 2500 J/KG AND PCP WATER VALUES MAXING OUT AROUND 1.7
INCHES THURS MORNING. THE ONE PIECE THAT WILL BE LACKING IS THE
TIMING DOES NOT COINCIDE WITH MAX HEATING.
AS FOR TEMPERATURES THURS WILL REMAIN AROUND CLIMO WITH CLOUDS AND
PCP HOLDING IT DOWN A BIT. FRI AFTN TEMPS SHOULD SOAR THROUGH THE
80S WITH SUNSHINE AND FEWER SHWRS EXPECTED AS WELL AS A MORE
WESTERLY FLOW THROUGH THE LOWER LEVELS OF THE ATMOSPHERE. TEMPS AT
NIGHT WILL REMAIN ABOVE NORMAL IN THE MID 60S MOST PLACES.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 3 PM WEDNESDAY...SLIGHT PATTERN SHIFT AS FLAT UPPER RIDGE IS
SUPPRESSED TO THE SOUTH AFTER THE WEEKEND. ONE MORE WARM DAY ON
SATURDAY WITH TEMPS NEAR 90 AWAY FROM THE IMMEDIATE COAST...BUT THE
FRONT AND UPPER DISTURBANCES WILL BE CLOSE ENOUGH TO WARRANT SLIGHT
CHANCE POPS. FRONT MOVES THROUGH SAT NIGHT AND SUNDAY...BUT COULD
REMAIN UNSETTLED INTO MONDAY DEPENDING ON THE VALIDITY OF UPPER
DISTURBANCES ADVERTISED BY GFS. WILL HOLD LOW CHANCE POPS IN FOR
MONDAY. DRIER HIGH PRESSURE RIDGING INTO THE CAROLINAS FROM THE
NORTH WILL KEEP TEMPS NEAR OR SLIGHTLY BELOW SEASONAL NORMALS
TUE-WED.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
A STATIONARY FRONT LOCATED ALONG THE VIRGINIA-NORTH CAROLINA
BORDER...EXTENDS SOUTHWEST TO NEAR KHKY. THE FRONT WILL CONTINUE TO
REMAIN NORTH OF THE TERMINALS THIS FORECAST PERIOD. THE BOUNDARY
FROM WHATS LEFT OF THE SQUALL LINE RESIDES NORTH-SOUTH...BASICALLY
ALONG AND IN THEVICINITY OF I-95. THIS WILL BE THE FOCUS FOR
CONVECTION THE REMAINDER OF THE NIGHT INTO DAYLIGHT THURSDAY.
DURING THURSDAY...ATMOSPHERIC CONDITIONS CONTINUE FOR A MODERATELY
UNSTABLE REGION WITH RIPPLES OF SHORT WAVE ENERGY MOVING WEST TO
EAST ACROSS THE AREA TERMINALS. TIMING OF THESE WAVES WILL BE KEY
IN THE TIME OF THE FORECAST OF THUNDERSTORMS. HAVE INCLUDED TEMPO
GROUPS TO ATLEAST TIME THE 1ST WAVE COMBINED WITH THE SFC
FEATURE...THE LEFTOVER BNDRY.
EXTENDED OUTLOOK THROUGH MONDAY...SCATTERED THUNDERSTORMS SUNDAY.
ISOLATED THUNDERSTORMS FRIDAY AND SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 9 PM WEDNESDAY...WE HAVE DELAYED THE START-TIME OF THE SMALL
CRAFT ADVISORY BY A FEW HOURS GIVEN THE BELOW-FORECAST WINDS AND
SEAS BEING REPORTED ACROSS THE COASTAL WATERS. MODEL GUIDANCE IS
VERY CONSISTENT THAT WINDS WILL INCREASE BY 5-6 KNOTS OVERNIGHT
WHICH WILL PUSH SPEEDS TOWARD 20 KT OUT AT FRYING PAN SHOALS...AND
INTO THE 15-20 KT RANGE WITHIN THE COASTAL WATERS.
WHAT IS LESS CERTAIN IS HOW QUICKLY SEAS WILL BUILD LATE TONIGHT.
THIS IS THE FIFTH DAY IN A ROW WHERE WAVEWATCH GUIDANCE HAS
OVERFORECAST SEAS BY AT LEAST 1 FOOT...AND GIVEN THAT THE SAME
THERMODYNAMICALLY STABLE BOUNDARY LAYER STILL EXISTS OVER THE
COASTAL WATERS WE ARE UNSURE HOW EFFICIENTLY THE INCREASED 10-METER
WIND SPEEDS WILL TRANSLATE DOWN TO THE SEA SURFACE WHERE WIND ENERGY
IS ACTUALLY TRANSFORMED INTO WAVES. OUR FORECAST HAS SEAS BUILDING
TO 4-6 FT NORTH OF LITTLE RIVER INLET LATE...AND TO 4-5 FT SOUTH OF
LITTLE RIVER INLET LATE.
A DYING SQUALL LINE ACROSS CENTRAL SOUTH CAROLINA WILL LIKELY NOT
BRING MUCH WEATHER TO THE COASTAL WATERS OVERNIGHT...HOWEVER AN
INCREASINGLY FAVORABLE UPPER LEVEL ENVIRONMENT FOR CONVECTION MAY
DEVELOP NEW SHOWERS AND THUNDERSTORMS...PARTICULARLY AFTER 4-5 AM.
THE BEST CHANCES APPEAR TO BE NEAR AND NORTH OF CAPE FEAR.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...SOUTHERLY WINDS EXPECTED THROUGH MOST OF
THE PERIOD. WILL START OUT WITH A GOOD 15 TO 20 KTS ON THURS WHICH
WILL PUSH SEAS INTO SCA CRITERIA FOR THE NORTHERN 2 ZONES. SCA
WILL BASICALLY RUN UP THROUGH MIDNIGHT THURS INTO FRI. OTHERWISE
SEAS WILL REMAIN IN THE 3 TO 5 FT RANGE MOST WATERS. WINDS TAKE ON
A MORE WESTERLY COMPONENT FOR A SHORT TIME LATE THURS AFTER
SHORTWAVE MOVES THROUGH.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 PM WEDNESDAY...MODEST SW FLOW WILL CARRY THROUGH SATURDAY
INTO SAT NIGHT...WITH SPEEDS 15-20 KT AHEAD OF THE APPROACHING
FRONT. FULLY DEVELOPED SEAS AT THAT POINT WILL BE KNOCKING ON THE
DOOR OF SCA...BUT FOR NOW WILL KEEP 3-5 FT IN THE OFFICIAL FORECAST.
FRONT DROPS THROUGH ON SUNDAY MORNING...WITH A WIND SHIFT TO THE
NORTH. NOT MUCH OF A SURGE BEHIND THE FRONT GIVEN WEAK CAA AND THE
RELUCTANCE OF THE HIGH PRESSURE TO BUILD IN. WIND SPEEDS WILL BE
10-15 KT THROUGH MONDAY...WITH SEAS SUBSIDING TO AROUND 2 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 AM THURSDAY TO 2 AM EDT FRIDAY
FOR AMZ250-252.
&&
$$
SYNOPSIS...RGZ
NEAR TERM...TRA
SHORT TERM...RGZ
LONG TERM...RAS
AVIATION...DCH/HAWKINS
000
FXUS62 KRAH 070554
AFDRAH
AREA FORECAST DISCUSSION...UPDATED.
NATIONAL WEATHER SERVICE RALEIGH NC
145 AM EDT THU MAY 7 2009
.SYNOPSIS...
A STRONG UPPER LEVEL DISTURBANCE WILL PIVOT ACROSS THE AREA BY
MIDDAY...BRINGING ANOTHER ROUND SHOWERS AND THUNDERSTORMS ACROSS
CENTRAL NORTH CAROLINA THROUGH THE AFTERNOON. A WEAK SURFACE TROUGH
WILL THEN LINGER ACROSS THE CAROLINAS THROUGH SATURDAY.
&&
.NEAR TERM /UNTIL 7 AM THURSDAY MORNING/...
AS OF 915 PM WEDNESDAY...
...A NEW TORNADO WATCH THAT WILL BE IN EFFECT THROUGH 400 AM HAS
REPLACED THE PREVIOUS ONE THAT WAS IN EFFECT THROUGH 900 PM...
THE SEVERE WEATHER PARAMETERS ARE MARGINALLY FAVORABLE FOR THE NEW
TORNADO WATCH. THE MOST FAVORABLE PARAMETERS SEEM TO BE SHIFTING
NORTHWARD... FOCUSING FROM NORTHERN NC INTO VA WHERE THE 0-1KM STORM
RELATIVE HELICITIES WERE GREATEST (250-350 M2/S2). HOWEVER... THE
SURFACE BASED AND 100 MB MIXED LAYER CAPES HAVE BEEN LESSENING WITH
LOSS OF HEATING... AND HAVE BEEN SHIFTING TO THE EASTERN PIEDMONT
AND WESTERN COASTAL PLAIN REGIONS.
THE LATEST WATER VAPOR SATELLITE IMAGERY INDICATED THE MID LEVEL LOW
WAS OVER WESTERN KENTUCKY MOVING EAST. AT LEAST SOME SCATTERED
THUNDERSTORMS ARE EXPECTED ACROSS NC OVERNIGHT AS LARGE SCALE
LIFTING INCREASES AHEAD OF THIS SYSTEM PER THE CURRENT ACTIVITY OVER
THE MOUNTAINS. THE DEEP LAYER SHEAR IS EXPECTED TO INCREASE TO
40-45KT OVERNIGHT. THE MOIST BOUNDARY LAYER AND UP TO 30KT OF LOW
LEVEL SHEAR SUGGEST THAT ISOLATED TORNADOES MAY CONTINUE TO BE THE
MAIN THREAT IN ANY STRONG CONVECTION.
THE RADAR TRENDS HAVE BEEN SHOWING A DECREASE IN THE CONVECTIVE
ACTIVITY SINCE 730 PM OVER CENTRAL NC.... WITH EVEN THE BOWING LINE
THAT WAS PUSHING INTO OUR SW PIEDMONT AROUND ALBEMARLE DIMINISHING
IN INTENSITY AS WELL. IT APPEARS THAT THIS COULD CHANGE IN THE NEXT
FEW HOURS AS THE LARGE SCALE LIFT INCREASES FROM THE WEST.
THERE HAS BEEN A GOOD AMOUNT OF SHOWERS WITH EMBEDDED THUNDERSTORMS
DEVELOPING AND EXPANDING ACROSS THE NC MOUNTAINS. AS THIS COMES
EAST... WE WILL SEE IF WE CAN GET ANYTHING UP CLOSE TO SEVERE OVER
THE TRIAD REGION IN THE NEXT FEW HOURS. WE WILL RAISE POP TO NEAR
CATEGORICAL OVER THE WEST TO ACCOUNT FOR THE ACTIVITY DEVELOPING
OVER THE MOUNTAINS AND PUSHING INTO THE PIEDMONT THROUGH THE LATE
EVENING. WE WILL BRING THIS ACTIVITY EASTWARD ACROSS OUR REGION
OVERNIGHT.
NO OTHER CHANGES AT THIS TIME.
&&
.SHORT TERM /7 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
AS OF 310 PM WEDNESDAY...
EXPECT ONGOING CONVECTION EAST OF HIGHWAY 1 TO EXIT REGION AFTER
15Z. APPEARS THAT AIR MASS WILL BE ABLE TO RECOVER AND SUPPORT
SCATTERED STRONG CONVECTION AFTER 19Z OVER ALL BUT THE FAR NW.
EXPECT CLOUDS EARLY THU TO SCATTERED OUT BY LATE MORNING...ENABLING
TEMPS TO SOAR TO NEAR 80/LOWER 80S BY EARLY AFTERNOON. WHILE LOW
LEVEL AIRMASS WILL BE QUITE UNSTABLE...WIND FIELD ALOFT AND MID
LEVEL LAPSE RATES SUGGEST THAT SEVERE STORMS SHOULD BE FEW IN NUMBER
AND CONSISTENT OF LARGE HAIL AND DAMAGING WIND GUSTS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
AS OF 340 PM WEDNESDAY...
A SURFACE BOUNDARY MOVING EAST THROUGH CENTRAL NORTH CAROLINA
THURSDAY NIGHT INTO EARLY FRIDAY MORNING WILL TAKE THE CHANCE FOR
RAIN WITH IT. LOWS THURSDAY NIGHT WILL BE IN THE LOW TO MID 60S.
HIGHS FRIDAY WILL BE IN THE 80S.
THE BREAK IN THE RAIN WILL BE SHORT LIVED AS UNSETTLED WEATHER WILL
TAKE OVER IN RESPONSE TO A SERIES OF SURFACE WAVES IN CONJUNCTION
WITH UPPER LEVEL DISTURBANCES MOVING THROUGH WESTERLY FLOW ALOFT
FRIDAY NIGHT THROUGH MONDAY NIGHT. PWAT VALUES THROUGH THIS PERIOD
WILL BE IN EXCESS OF ONE INCH. LOWS FRIDAY AND SATURDAY NIGHT WILL
BE IN THE 60S... COOLING TO THE 50S FOR THE FIRST OF NEXT WEEK.
HIGHS SATURDAY IN THE 80S WILL DROP TO THE 70S BY MONDAY.
HIGH PRESSURE WILL BUILD OVER CENTRAL NORTH CAROLINA FROM THE
NORTHWEST TUESDAY INTO WEDNESDAY. HIGHS TUESDAY AND WEDNESDAY WILL
BE IN THE 70S. LOWS TUESDAY NIGHT WILL BE IN THE 50S.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 145 AM THURSDAY...
A LINE OF CONVECTION WILL MOVE FROM RDU EAST OVER THE NEXT COUPLE OF
HOURS BRINGING A BRIEF PERIOD OF MVFR CONDITIONS IN THE HEAVY RAIN
SHOWERS AND ISOLATED STRONG WIND GUSTS. WILL HAVE TO BE ON THE
LOOKOUT FOR A SECOND AREA OF SHOWERS AND THUNDERSTORMS CURRENTLY
RACING EAST ACROSS THE SOUTHERN APPALACHIANS...WHICH WILL BRING
ANOTHER 2 TO 3 HOUR PERIOD OF MVFR CONDITIONS...ESPECIALLY FROM RDU
EAST...AS THE STORMS ENTER IN AN AREA OF BETTER INSTABILITY. MODELS
BRING THIS SECOND AREA OF CONVECTION ACROSS THE EASTERN HALF OF 15Z.
CEILINGS SHOULD SCATTER OUT TO VFR BY LATE MORNING...AND THEN BECOME
BROKEN AGAIN AS STRONG AFTERNOON HEATING WILL ALLOW FOR CONVECTION
TO DEVELOP ALONG A WEAK SURFACE TROUGH LOCATED ACROSS THE WESTERN
PIEDMONT. LOSS OF DAYTIME HEATING SHOULD GREATLY DIMINISH CONVECTIVE
ACTIVITY WITH SCATTERED VFR CEILINGS OVERNIGHT.
UNSETTLED WEATHER EXPECTED FRIDAY NIGHT THROUGH MONDAY AS A COLD
FRONT APPROACHES THEN STALLS IN OUR VICINITY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...BADGETT/RHJ
SHORT TERM...BL
LONG TERM...BADGETT/RHJ
AVIATION...RHJ
000
FXUS62 KMHX 070155
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
955 PM EDT WED MAY 6 2009
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN NW OF REGION INTO SATURDAY. A COLD
FRONT WILL MOVE SE THROUGH THE REGION LATER SATURDAY NIGHT AND EARLY
SUNDAY. HIGH PRESSURE WILL BUILD NORTH OF THE REGION MONDAY THROUGH
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 9 PM WED...CONVECTION HAS BEEN WELL N AND W OF REGION THIS
EVENING NEAR BNDRY AND WELL AHEAD OF APPROACHING SRT WAVE. EXPECT
REST OF EVENING TO BE RATHER QUIET ESPCLY CST WITH ACTVTY INCREASING
LATE AHEAD OF DECENT SRT WAVE. CONTINUED LIKELY POPS LATE INLAND
WITH CHC CST. ALTHOUGH INSTAB WILL BE GRADUALLY WEAKENING WILL HAVE
INCREASING FORCING AND SHEAR LATE SO CANT RULE OUT POSS OF A FEW
SEVERE STORMS LATE.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
UNSTTLD WX WL CONT THRU THE RMNDR OF THE WK AS UPR TROF SLOWLY
APPRCHS FRM THE W. MDLS SHOWG UPR TROF MVS THRU AREA THU NGT. LWR
MSTR AND LACK OF UPR LVL ENERGY ON FRI SHUD HELP KP THE DAY DRY.
ANTHR S/WV MVS THRU THE FLO FRI NGT. DOESNT APPR TO HV TOO MUCH MSTR
WI THIS. ANTHR SYS APPCHS IN THE FAST FLO APPRCHS SAT WI A WK UPR
LVL S/WV SO WL HV LO POPS SAT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
FRNT TO MV THRU AREA SAT NGT WI LO LVL FLO BCMG NLY. ANTHR SURGE
APPRS TO DROP THRU AND DISSIPATE SUNDAY NGT. STL RMNG IN ZNL FLO
ALFT WI WK S/WVS ZIPPG THRU THE FLO. THIS WL KP A CHC OF SHWRS OVR
CWA THRU FIRST PART OF THE WK. UPR RDG TO BLD IN ON TUE WI SFC RDG
BLDG DWN FRM THE N.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
VFR WILL PREVAIL ACROSS THE TERMINALS THE REMAINDER OF THE
EVENING. SOME MVFR CIGS EXPECTED TO DEVELOP AFT 07Z ESPECIALLY
OVER THE KPGV AND KISO TERMINALS. CIGS EXPECTED TO LIFT TO VFR AFT
14Z BUT SHRA/TS EXPECTED TO INCREASE THU MORNING AS A DECENT SHORT
WAVE APPROACHES. PREVAILING VFR EXPECTED ALL TERMINALS THU BUT
PERIODS OF MAINLY MVFR CONDITIONS EXPECTED WITH ANY CONVECTION.
PREDOMINANT VFR EXPECTED THIS WEEKEND OUTSIDE OF ANY DIURNAL
CONVECTION THAT WILL BE POSSIBLE. A COLD FRONT WILL MOVE
ACROSS THE TERMINALS ON SUN WITH SHRA/TS ENDING.
&&
.MARINE...
LITTLE CHANGE TO MARINE GRIDS THIS UPDATE. SW WINDS CONTINUE TO
BE WEAKER ACROSS AREA WATERS THEN CURRENT MODELS SUGGEST. SEAS
ALSO LOWER WITH 3 TO 5 FT ACROSS THE AREA. LATEST MODEL GUIDANCE
DOES SHOW WINDS INCREASING LATER TONIGHT INTO THU WITH SEAS
BUILDING TO 5 TO 7 FT. THE GFS IS MUCH STRONGER WITH THE SW FLOW
COMPARED TO THE OTHER SHORT RANGE GUIDANCE. OPC NOT FAVORING THE
GFS IN THE SHORT TERM AND CURRENT WIND SPEEDS MAY BE TOO HIGH OVER
OUR WATERS FOR THU. HAVE OPTED TO KEEP HEADLINES AS IS FOR NOW AND
LET THE MID SHIFT TAKE A LOOK AT THE LATEST GUIDANCE TO DETERMINE
IF/WHERE ADJUSTMENTS TO ANY HEADLINES WILL BE NEEDED.
A QUASI- STATIONARY FRONT WILL REMAIN JUST TO THE WEST OF THE
WATERS THROUGH SUNDAY. SEVERAL SHORTWAVE TROUGHS WILL INTERACT
WITH THE BOUNDARY PRODUCING WEAK FRONTAL WAVES WHICH WILL ENHANCE
THE SW FLOW AND PRODUCE WINDS AROUND 25 KT AND SEAS 6-8 FT. THE
FRONT IS EXPECTED TO FINALLY SINK SOUTH OF THE WATERS SUNDAY
EVENING WITH THE FLOW TURNING TO NE. THE NEW GFS AND ECMWF ARE
STRONGER WITH THE POST FRONTAL NE FLOW (20 KT) INDICATING A
CONTINUATION OF ADVISORY OF NEAR ADVISORY CONDITIONS FROM CAPE
LOOKOUT TO OREGON INLET. THE EXTREME NORTHERN AND SOUTHERN WATERS
MAY IMPROVE BELOW ADVISORY CRITERIA MONDAY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM TO 2 PM EDT THURSDAY FOR AMZ130-
135.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT SUNDAY FOR AMZ152-154-156-
158.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT THURSDAY FOR AMZ150.
&&
$$
SYNOPSIS...RF
NEAR TERM...RF
SHORT TERM...CGG
LONG TERM...CGG
AVIATION...JW/JME
MARINE...JW/JME
000
FXUS62 KILM 070132 CCA
AFDILM
AREA FORECAST DISCUSSION...CORRECTED NEAR TERM DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
932 PM EDT WED MAY 6 2009
.SYNOPSIS...
A LOW TO MID LEVEL TROUGH APPROACHING THE EASTERN CAROLINAS TONIGHT
WILL PASS OVERHEAD THURSDAY PRODUCING SHOWER AND THUNDERSTORM
ACTIVITY. WARMER AND DRIER WEATHER WILL PREVAIL ON FRIDAY AND
SATURDAY AS HIGH PRESSURE NOSES IN FROM THE WEST. A COLD FRONT WILL
MOVE ACROSS THE AREA SATURDAY NIGHT AND SUNDAY MORNING BRINGING
DRIER AIR FOR THE EARLY PART OF NEXT WEEK...AS HIGH PRESSURE BUILDS
INTO THE REGION FROM THE NORTH THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 9 PM WEDNESDAY...THE SQUALL LINE THAT PROMPTED NUMEROUS
WARNINGS ACROSS GEORGIA AND THE WESTERN CAROLINAS EARLIER TODAY IS
DYING AS IT MOVES OUT AHEAD OF ITS UPPER LEVEL SUPPORT. THE
RESIDUAL LINE OF SPRINKLES WILL BE IN THE PEE DEE REGION BY 10-11
PM. THE UPPER LEVEL TROUGH CURRENTLY OVER NW GA/TN WILL SHIFT EAST
AFTER MIDNIGHT AND WILL BRING THE EASTERN CAROLINAS INTO AN
INCREASINGLY FAVORABLE ENVIRONMENT FOR NEW CONVECTION TO DEVELOP
DESPITE THE UNFAVORABLE TIME OF DAY. FORECAST SOUNDINGS FROM THE NAM
AND GFS SHOW ELEVATED INSTABILITY ROOTED IN THE 950/925 MB LAYER
COULD SUSTAIN HEALTHY (ALTHOUGH PERHAPS NOT SEVERE) THUNDERSTORMS...
ESPECIALLY AFTER 2-3 AM. THE BEST CHANCE APPEARS TO BE IN THE
BENNETTSVILLE/LUMBERTON AREA INITIALLY...THEN SHIFTING THROUGH
ELIZABETHTOWN AND WHITEVILLE BY 4-5 AM AND TO THE CAPE FEAR COAST BY
DAYBREAK. A 35-KNOT LOW LEVEL JET AT 925 MB WILL PROVIDE A STEADY
SOURCE OF WARM MOIST AIR NORTHWARD.
WITH THE LOW LEVEL JET KEEPING SURFACE WINDS IN THE 8-15 MPH RANGE
OVERNIGHT...LOW TEMPERATURES WILL CONTINUE TO RUN QUITE MILD FOR THE
TIME OF YEAR. WE ARE EXPECTING LOWS NEAR 70 ALONG THE COAST WITH
UPPER 60S INLAND. IF SUSTAINED HEAVY CONVECTION CAN OCCUR (NOT
REALLY EXPECTED AT THIS TIME) TEMPERATURES COULD BOTTOM OUT A FEW
DEGREES COOLER IN SPOTS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...A FAIRLY DECENT SHORTWAVE WILL MOVE THROUGH
ON THURS WITH A RELATIVELY ZONAL FLOW TO FOLLOW AND A LESS
IMPRESSIVE RIPPLE IN THE FLOW LATE FRI. THIS SHORTWAVE WILL
TRANSLATE DOWN THROUGH THE LOWER LEVELS WITH TROUGH MOVING THROUGH
THURS AFTN. EXPECT MOST SHWR/TSTM ACTIVITY TO OCCUR MORE TOWARD
THE BEGINNING OF THE PERIOD AS SHORTWAVE TRAVERSES THE AREA AND
SHOULD TAPER OFF BY THURS EVENING FROM WEST TO EAST. ONCE
SHORTWAVE AND ASSOCIATED LOWER LEVEL TROUGH PASSES ON THURS GFS
SHOWS A NICE DRY PUNCH MOVING IN AS WINDS THROUGH THE LOWER TO MID
LEVELS SHIFT AROUND TO THE W-NW AND WILL MAINTAIN A WESTERLY
COMPONENT THROUGH THE REMAINDER OF THE PERIOD. BY FRI ANY SHOWER
ACTIVITY WILL BE FOCUSED ALONG SEA BREEZE IN THE AFTN AS IT PUSHES
INLAND. THURS WILL DEFINITELY BE THE MORE ACTIVE DAY WITH GFS/NAM
AND SREF SHOWING BEST CHC OF PCP AROUND 12 TO 18Z. MU CAPE WILL BE
UP TO AROUND 2500 J/KG AND PCP WATER VALUES MAXING OUT AROUND 1.7
INCHES THURS MORNING. THE ONE PIECE THAT WILL BE LACKING IS THE
TIMING DOES NOT COINCIDE WITH MAX HEATING.
AS FOR TEMPERATURES THURS WILL REMAIN AROUND CLIMO WITH CLOUDS AND
PCP HOLDING IT DOWN A BIT. FRI AFTN TEMPS SHOULD SOAR THROUGH THE
80S WITH SUNSHINE AND FEWER SHWRS EXPECTED AS WELL AS A MORE
WESTERLY FLOW THROUGH THE LOWER LEVELS OF THE ATMOSPHERE. TEMPS AT
NIGHT WILL REMAIN ABOVE NORMAL IN THE MID 60S MOST PLACES.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 3 PM WEDNESDAY...SLIGHT PATTERN SHIFT AS FLAT UPPER RIDGE IS
SUPPRESSED TO THE SOUTH AFTER THE WEEKEND. ONE MORE WARM DAY ON
SATURDAY WITH TEMPS NEAR 90 AWAY FROM THE IMMEDIATE COAST...BUT THE
FRONT AND UPPER DISTURBANCES WILL BE CLOSE ENOUGH TO WARRANT SLIGHT
CHANCE POPS. FRONT MOVES THROUGH SAT NIGHT AND SUNDAY...BUT COULD
REMAIN UNSETTLED INTO MONDAY DEPENDING ON THE VALIDITY OF UPPER
DISTURBANCES ADVERTISED BY GFS. WILL HOLD LOW CHANCE POPS IN FOR
MONDAY. DRIER HIGH PRESSURE RIDGING INTO THE CAROLINAS FROM THE
NORTH WILL KEEP TEMPS NEAR OR SLIGHTLY BELOW SEASONAL NORMALS
TUE-WED.
&&
.AVIATION /00Z WEDNESDAY THROUGH MONDAY/...
A STATIONARY FRONT LOCATED ALONG THE VIRGINIA-NORTH CAROLINA EXTENDS
SOUTHWEST TO NEAR KHKY AND THE FRONT WILL CONTINUE TO REMAIN NORTH
OF THE TAF SITES THIS FORECAST PERIOD. A SQUALL LINE IN WESTERN
SOUTH CAROLINA IS EXPECTED TO CONTINUE ITS EASTERN PUSH AND SHOULD
IMPACT THE KLBT AND KFLO TAF SITES AROUND 02 UTC AND THE COASTAL TAF
SITES BETWEEN 03 AND 04 UTC.
CONDITIONS CONTINUE FOR A MODERATELY UNSTABLE REGION WITH RIPPLES OF
SHORT WAVE ENERGY MOVING WEST TO EAST ACROSS THE AREA. TIMING OF
THESE WAVES WILL BE KEY IN THE TIME OF THE FORECAST. WILL MAINTAIN
VFR CONDITIONS WITH MVFR IMPACTS WITH THUNDERSTORMS. AT THIS TIME
WILL REFRAIN FROM MENTION OF THE IFR.
EXTENDED OUTLOOK THROUGH MONDAY...SCATTERED THUNDERSTORMS THURSDAY
AND SUNDAY. ISOLATED THUNDERSTORMS FRIDAY AND SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 9 PM WEDNESDAY...WE HAVE DELAYED THE START-TIME OF THE SMALL
CRAFT ADVISORY BY A FEW HOURS GIVEN THE BELOW-FORECAST WINDS AND
SEAS BEING REPORTED ACROSS THE COASTAL WATERS. MODEL GUIDANCE IS
VERY CONSISTENT THAT WINDS WILL INCREASE BY 5-6 KNOTS OVERNIGHT
WHICH WILL PUSH SPEEDS TOWARD 20 KT OUT AT FRYING PAN SHOALS...AND
INTO THE 15-20 KT RANGE WITHIN THE COASTAL WATERS.
WHAT IS LESS CERTAIN IS HOW QUICKLY SEAS WILL BUILD LATE TONIGHT.
THIS IS THE FIFTH DAY IN A ROW WHERE WAVEWATCH GUIDANCE HAS
OVERFORECAST SEAS BY AT LEAST 1 FOOT...AND GIVEN THAT THE SAME
THERMODYNAMICALLY STABLE BOUNDARY LAYER STILL EXISTS OVER THE
COASTAL WATERS WE ARE UNSURE HOW EFFICIENTLY THE INCREASED 10-METER
WIND SPEEDS WILL TRANSLATE DOWN TO THE SEA SURFACE WHERE WIND ENERGY
IS ACTUALLY TRANSFORMED INTO WAVES. OUR FORECAST HAS SEAS BUILDING
TO 4-6 FT NORTH OF LITTLE RIVER INLET LATE...AND TO 4-5 FT SOUTH OF
LITTLE RIVER INLET LATE.
A DYING SQUALL LINE ACROSS CENTRAL SOUTH CAROLINA WILL LIKELY NOT
BRING MUCH WEATHER TO THE COASTAL WATERS OVERNIGHT...HOWEVER AN
INCREASINGLY FAVORABLE UPPER LEVEL ENVIRONMENT FOR CONVECTION MAY
DEVELOP NEW SHOWERS AND THUNDERSTORMS...PARTICULARLY AFTER 4-5 AM.
THE BEST CHANCES APPEAR TO BE NEAR AND NORTH OF CAPE FEAR.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...SOUTHERLY WINDS EXPECTED THROUGH MOST OF
THE PERIOD. WILL START OUT WITH A GOOD 15 TO 20 KTS ON THURS WHICH
WILL PUSH SEAS INTO SCA CRITERIA FOR THE NORTHERN 2 ZONES. SCA
WILL BASICALLY RUN UP THROUGH MIDNIGHT THURS INTO FRI. OTHERWISE
SEAS WILL REMAIN IN THE 3 TO 5 FT RANGE MOST WATERS. WINDS TAKE ON
A MORE WESTERLY COMPONENT FOR A SHORT TIME LATE THURS AFTER
SHORTWAVE MOVES THROUGH.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 PM WEDNESDAY...MODEST SW FLOW WILL CARRY THROUGH SATURDAY
INTO SAT NIGHT...WITH SPEEDS 15-20 KT AHEAD OF THE APPROACHING
FRONT. FULLY DEVELOPED SEAS AT THAT POINT WILL BE KNOCKING ON THE
DOOR OF SCA...BUT FOR NOW WILL KEEP 3-5 FT IN THE OFFICIAL FORECAST.
FRONT DROPS THROUGH ON SUNDAY MORNING...WITH A WIND SHIFT TO THE
NORTH. NOT MUCH OF A SURGE BEHIND THE FRONT GIVEN WEAK CAA AND THE
RELUCTANCE OF THE HIGH PRESSURE TO BUILD IN. WIND SPEEDS WILL BE
10-15 KT THROUGH MONDAY...WITH SEAS SUBSIDING TO AROUND 2 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 AM THURSDAY TO 2 AM EDT FRIDAY
FOR AMZ250-252.
&&
$$
SYNOPSIS...RGZ
NEAR TERM...TRA
SHORT TERM...RGZ
LONG TERM...RAS
AVIATION...HAWKINS
000
FXUS62 KILM 070130
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
930 PM EDT WED MAY 6 2009
.SYNOPSIS...
A LOW TO MID LEVEL TROUGH APPROACHING THE EASTERN CAROLINAS TONIGHT
WILL PASS OVERHEAD THURSDAY PRODUCING SHOWER AND THUNDERSTORM
ACTIVITY. WARMER AND DRIER WEATHER WILL PREVAIL ON FRIDAY AND
SATURDAY AS HIGH PRESSURE NOSES IN FROM THE WEST. A COLD FRONT WILL
MOVE ACROSS THE AREA SATURDAY NIGHT AND SUNDAY MORNING BRINGING
DRIER AIR FOR THE EARLY PART OF NEXT WEEK...AS HIGH PRESSURE BUILDS
INTO THE REGION FROM THE NORTH THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 9 PM WEDNESDAY...THE SQUALL LINE THAT PROMPTED NUMEROUS
WARNINGS ACROSS GEORGIA AND THE WESTERN CAROLINAS EARLIER TODAY IS
DYING AS IT MOVES OUT AHEAD OF ITS UPPER LEVEL SUPPORT. THE
RESIDUAL LINE OF SPRINKLES WILL BE IN THE PEE DEE REGION BY 10-11
PM. THE UPPER LEVEL TROUGH CURRENTLY OVER NW GA/TN WILL SHIFT EAST
AFTER MIDNIGHT AND WILL BRING THE EASTERN CAROLINAS INTO AN
INCREASINGLY FAVORABLE ENVIRONMENT FOR NEW CONVECTION TO DEVELOP
DESPITE THE UNFAVORABLE TIME OF DAY. FORECAST SOUNDINGS FROM THE NAM
AND GFS SHOW ELEVATED CONVECTION ROOTED IN THE 950/925 MB LAYER
COULD SUSTAIN HEALTHY (ALTHOUGH PERHAPS NOT SEVERE) THUNDERSTORMS...
ESPECIALLY AFTER 2-3 AM. THE BEST CHANCE APPEARS TO BE IN THE
BENNETTSVILLE/LUMBERTON AREA INITIALLY...THEN SHIFTING THROUGH
ELIZABETHTOWN AND WHITEVILLE BY 4-5 AM AND TO THE CAPE FEAR COAST BY
DAYBREAK. A 35-KNOT LOW LEVEL JET AT 925 MB WILL PROVIDE A STEADY
SOURCE OF WARM MOIST AIR NORTHWARD.
WITH THE LOW LEVEL JET KEEPING SURFACE WINDS IN THE 8-15 MPH RANGE
OVERNIGHT...LOW TEMPERATURES WILL CONTINUE TO RUN QUITE MILD FOR THE
TIME OF YEAR. WE ARE EXPECTING LOWS NEAR 70 ALONG THE COAST WITH
UPPER 60S INLAND. IF SUSTAINED HEAVY CONVECTION CAN OCCUR (NOT
REALLY EXPECTED AT THIS TIME) TEMPERATURES COULD BOTTOM OUT A FEW
DEGREES COOLER IN SPOTS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...A FAIRLY DECENT SHORTWAVE WILL MOVE THROUGH
ON THURS WITH A RELATIVELY ZONAL FLOW TO FOLLOW AND A LESS
IMPRESSIVE RIPPLE IN THE FLOW LATE FRI. THIS SHORTWAVE WILL
TRANSLATE DOWN THROUGH THE LOWER LEVELS WITH TROUGH MOVING THROUGH
THURS AFTN. EXPECT MOST SHWR/TSTM ACTIVITY TO OCCUR MORE TOWARD
THE BEGINNING OF THE PERIOD AS SHORTWAVE TRAVERSES THE AREA AND
SHOULD TAPER OFF BY THURS EVENING FROM WEST TO EAST. ONCE
SHORTWAVE AND ASSOCIATED LOWER LEVEL TROUGH PASSES ON THURS GFS
SHOWS A NICE DRY PUNCH MOVING IN AS WINDS THROUGH THE LOWER TO MID
LEVELS SHIFT AROUND TO THE W-NW AND WILL MAINTAIN A WESTERLY
COMPONENT THROUGH THE REMAINDER OF THE PERIOD. BY FRI ANY SHOWER
ACTIVITY WILL BE FOCUSED ALONG SEA BREEZE IN THE AFTN AS IT PUSHES
INLAND. THURS WILL DEFINITELY BE THE MORE ACTIVE DAY WITH GFS/NAM
AND SREF SHOWING BEST CHC OF PCP AROUND 12 TO 18Z. MU CAPE WILL BE
UP TO AROUND 2500 J/KG AND PCP WATER VALUES MAXING OUT AROUND 1.7
INCHES THURS MORNING. THE ONE PIECE THAT WILL BE LACKING IS THE
TIMING DOES NOT COINCIDE WITH MAX HEATING.
AS FOR TEMPERATURES THURS WILL REMAIN AROUND CLIMO WITH CLOUDS AND
PCP HOLDING IT DOWN A BIT. FRI AFTN TEMPS SHOULD SOAR THROUGH THE
80S WITH SUNSHINE AND FEWER SHWRS EXPECTED AS WELL AS A MORE
WESTERLY FLOW THROUGH THE LOWER LEVELS OF THE ATMOSPHERE. TEMPS AT
NIGHT WILL REMAIN ABOVE NORMAL IN THE MID 60S MOST PLACES.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 3 PM WEDNESDAY...SLIGHT PATTERN SHIFT AS FLAT UPPER RIDGE IS
SUPPRESSED TO THE SOUTH AFTER THE WEEKEND. ONE MORE WARM DAY ON
SATURDAY WITH TEMPS NEAR 90 AWAY FROM THE IMMEDIATE COAST...BUT THE
FRONT AND UPPER DISTURBANCES WILL BE CLOSE ENOUGH TO WARRANT SLIGHT
CHANCE POPS. FRONT MOVES THROUGH SAT NIGHT AND SUNDAY...BUT COULD
REMAIN UNSETTLED INTO MONDAY DEPENDING ON THE VALIDITY OF UPPER
DISTURBANCES ADVERTISED BY GFS. WILL HOLD LOW CHANCE POPS IN FOR
MONDAY. DRIER HIGH PRESSURE RIDGING INTO THE CAROLINAS FROM THE
NORTH WILL KEEP TEMPS NEAR OR SLIGHTLY BELOW SEASONAL NORMALS
TUE-WED.
&&
.AVIATION /00Z WEDNESDAY THROUGH MONDAY/...
A STATIONARY FRONT LOCATED ALONG THE VIRGINIA-NORTH CAROLINA EXTENDS
SOUTHWEST TO NEAR KHKY AND THE FRONT WILL CONTINUE TO REMAIN NORTH
OF THE TAF SITES THIS FORECAST PERIOD. A SQUALL LINE IN WESTERN
SOUTH CAROLINA IS EXPECTED TO CONTINUE ITS EASTERN PUSH AND SHOULD
IMPACT THE KLBT AND KFLO TAF SITES AROUND 02 UTC AND THE COASTAL TAF
SITES BETWEEN 03 AND 04 UTC.
CONDITIONS CONTINUE FOR A MODERATELY UNSTABLE REGION WITH RIPPLES OF
SHORT WAVE ENERGY MOVING WEST TO EAST ACROSS THE AREA. TIMING OF
THESE WAVES WILL BE KEY IN THE TIME OF THE FORECAST. WILL MAINTAIN
VFR CONDITIONS WITH MVFR IMPACTS WITH THUNDERSTORMS. AT THIS TIME
WILL REFRAIN FROM MENTION OF THE IFR.
EXTENDED OUTLOOK THROUGH MONDAY...SCATTERED THUNDERSTORMS THURSDAY
AND SUNDAY. ISOLATED THUNDERSTORMS FRIDAY AND SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 9 PM WEDNESDAY...WE HAVE DELAYED THE START-TIME OF THE SMALL
CRAFT ADVISORY BY A FEW HOURS GIVEN THE BELOW-FORECAST WINDS AND
SEAS BEING REPORTED ACROSS THE COASTAL WATERS. MODEL GUIDANCE IS
VERY CONSISTENT THAT WINDS WILL INCREASE BY 5-6 KNOTS OVERNIGHT
WHICH WILL PUSH SPEEDS TOWARD 20 KT OUT AT FRYING PAN SHOALS...AND
INTO THE 15-20 KT RANGE WITHIN THE COASTAL WATERS.
WHAT IS LESS CERTAIN IS HOW QUICKLY SEAS WILL BUILD LATE TONIGHT.
THIS IS THE FIFTH DAY IN A ROW WHERE WAVEWATCH GUIDANCE HAS
OVERFORECAST SEAS BY AT LEAST 1 FOOT...AND GIVEN THAT THE SAME
THERMODYNAMICALLY STABLE BOUNDARY LAYER STILL EXISTS OVER THE
COASTAL WATERS WE ARE UNSURE HOW EFFICIENTLY THE INCREASED 10-METER
WIND SPEEDS WILL TRANSLATE DOWN TO THE SEA SURFACE WHERE WIND ENERGY
IS ACTUALLY TRANSFORMED INTO WAVES. OUR FORECAST HAS SEAS BUILDING
TO 4-6 FT NORTH OF LITTLE RIVER INLET LATE...AND TO 4-5 FT SOUTH OF
LITTLE RIVER INLET LATE.
A DYING SQUALL LINE ACROSS CENTRAL SOUTH CAROLINA WILL LIKELY NOT
BRING MUCH WEATHER TO THE COASTAL WATERS OVERNIGHT...HOWEVER AN
INCREASINGLY FAVORABLE UPPER LEVEL ENVIRONMENT FOR CONVECTION MAY
DEVELOP NEW SHOWERS AND THUNDERSTORMS...PARTICULARLY AFTER 4-5 AM.
THE BEST CHANCES APPEAR TO BE NEAR AND NORTH OF CAPE FEAR.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...SOUTHERLY WINDS EXPECTED THROUGH MOST OF
THE PERIOD. WILL START OUT WITH A GOOD 15 TO 20 KTS ON THURS WHICH
WILL PUSH SEAS INTO SCA CRITERIA FOR THE NORTHERN 2 ZONES. SCA
WILL BASICALLY RUN UP THROUGH MIDNIGHT THURS INTO FRI. OTHERWISE
SEAS WILL REMAIN IN THE 3 TO 5 FT RANGE MOST WATERS. WINDS TAKE ON
A MORE WESTERLY COMPONENT FOR A SHORT TIME LATE THURS AFTER
SHORTWAVE MOVES THROUGH.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 PM WEDNESDAY...MODEST SW FLOW WILL CARRY THROUGH SATURDAY
INTO SAT NIGHT...WITH SPEEDS 15-20 KT AHEAD OF THE APPROACHING
FRONT. FULLY DEVELOPED SEAS AT THAT POINT WILL BE KNOCKING ON THE
DOOR OF SCA...BUT FOR NOW WILL KEEP 3-5 FT IN THE OFFICIAL FORECAST.
FRONT DROPS THROUGH ON SUNDAY MORNING...WITH A WIND SHIFT TO THE
NORTH. NOT MUCH OF A SURGE BEHIND THE FRONT GIVEN WEAK CAA AND THE
RELUCTANCE OF THE HIGH PRESSURE TO BUILD IN. WIND SPEEDS WILL BE
10-15 KT THROUGH MONDAY...WITH SEAS SUBSIDING TO AROUND 2 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 AM THURSDAY TO 2 AM EDT FRIDAY
FOR AMZ250-252.
&&
$$
SYNOPSIS...RGZ
NEAR TERM...TRA
SHORT TERM...RGZ
LONG TERM...RAS
AVIATION...HAWKINS
000
FXUS62 KMHX 070113
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
914 PM EDT WED MAY 6 2009
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN NW OF REGION INTO SATURDAY. A COLD
FRONT WILL MOVE SE THROUGH THE REGION LATER SATURDAY NIGHT AND EARLY
SUNDAY. HIGH PRESSURE WILL BUILD NORTH OF THE REGION MONDAY THROUGH
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 9 PM WED...CONVECTION HAS BEEN WELL N AND W OF REGION THIS
EVENING NEAR BNDRY AND WELL AHEAD OF APPROACHING SRT WAVE. EXPECT
REST OF EVENING TO BE RATHER QUIET ESPCLY CST WITH ACTVTY INCREASING
LATE AHEAD OF DECENT SRT WAVE. CONTINUED LIKELY POPS LATE INLAND
WITH CHC CST. ALTHOUGH INSTAB WILL BE GRADUALLY WEAKENING WILL HAVE
INCREASING FORCING AND SHEAR LATE SO CANT RULE OUT POSS OF A FEW
SEVERE STORMS LATE.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
UNSTTLD WX WL CONT THRU THE RMNDR OF THE WK AS UPR TROF SLOWLY
APPRCHS FRM THE W. MDLS SHOWG UPR TROF MVS THRU AREA THU NGT. LWR
MSTR AND LACK OF UPR LVL ENERGY ON FRI SHUD HELP KP THE DAY DRY.
ANTHR S/WV MVS THRU THE FLO FRI NGT. DOESNT APPR TO HV TOO MUCH MSTR
WI THIS. ANTHR SYS APPCHS IN THE FAST FLO APPRCHS SAT WI A WK UPR
LVL S/WV SO WL HV LO POPS SAT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
FRNT TO MV THRU AREA SAT NGT WI LO LVL FLO BCMG NLY. ANTHR SURGE
APPRS TO DROP THRU AND DISSIPATE SUNDAY NGT. STL RMNG IN ZNL FLO
ALFT WI WK S/WVS ZIPPG THRU THE FLO. THIS WL KP A CHC OF SHWRS OVR
CWA THRU FIRST PART OF THE WK. UPR RDG TO BLD IN ON TUE WI SFC RDG
BLDG DWN FRM THE N.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
SCATTERED STRONG CONVECTION EXPECTED THROUGH THIS EVENING MAINLY
VICINITY OF KISO/KPGV. FOLLOWING THE NAM MODEL BRINGS IN
WIDESPREAD CONVECTION AFTER 08Z TONIGHT THROUGH 16Z THURSDAY THEN
ISOLATED THURSDAY AFTERNOON/EVENING. THUS WILL INTRODUCE
PREVAILING MVFR CONDITIONS LATE TONIGHT THROUGH 16-17Z THURSDAY.
FORECAST THROUGH SUNDAY WILL FEATURE WARM SECTOR CONDITIONS WITH
MAINLY AFTERNOON/EVENING SHOWERS AND STORMS. LOOKS LIKE A DRYING
COOL FRONT WILL PUSH SOUTH OF THE AREA MONDAY WITH A LULL IN THE
PRECIPITATION PATTERN EXPECTED.
&&
.MARINE...
ACTIVE PATTERN THE NEXT SEVERAL DAYS WILL PRODUCE SHORT PERIOD
STEEP WIND WAVES AND SW WINDS 20-25 KT THROUGH SATURDAY EVENING
PROMPTING THE ISSUANCE OF SMALL CRAFT ADVISORIES FOR ALL THE
WATERS. THE ADVISORY CONDITIONS COULD BEGIN TO EASE SUNDAY
EVENING AS A FRONT DRIFTS SOUTH OF THE WATERS.
SW FLOW WILL INCREASE THIS EVENING AS LOW LEVEL JET MOVES OVER THE
AREA IN ADVANCE OF A SHORT WAVE TROUGH ALOFT. A QUASI-STATIONARY
FRONT WILL REMAIN JUST TO THE WEST OF THE WATERS THROUGH SUNDAY.
SEVERAL SHORTWAVE TROUGHS WILL INTERACT WITH THE BOUNDARY
PRODUCING WEAK FRONTAL WAVES WHICH WILL ENHANCE THE SW FLOW AND
PRODUCE WINDS AROUND 25 KT AND SEAS 6-8 FT. THE FRONT IS EXPECTED
TO FINALLY SINK SOUTH OF THE WATERS SUNDAY EVENING WITH THE FLOW
TURNING TO NE. THE NEW GFS AND ECMWF ARE STRONGER WITH THE POST
FRONTAL NE FLOW (20 KT) INDICATING A CONTINUATION OF ADVISORY OF
NEAR ADVISORY CONDITIONS FROM CAPE LOOKOUT TO OREGON INLET. THE
EXTREME NORTHERN AND SOUTHERN WATERS MAY IMPROVE BELOW ADVISORY
CRITERIA MONDAY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM TO 2 PM EDT THURSDAY FOR AMZ130-
135.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT SUNDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT SUNDAY FOR AMZ156-158.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT THURSDAY FOR AMZ150.
&&
$$
SYNOPSIS...RF
NEAR TERM...RF
SHORT TERM...CGG
LONG TERM...CGG
AVIATION...JME
MARINE...JME
000
FXUS62 KRAH 070107
AFDRAH
AREA FORECAST DISCUSSION...UPDATED.
NATIONAL WEATHER SERVICE RALEIGH NC
915 PM EDT WED MAY 6 2009
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES WILL RESULT IN SEVERAL ROUNDS
OF SCATTERED SHOWERS AND THUNDERSTORMS ACROSS CENTRAL NORTH CAROLINA
THROUGH THURSDAY.
&&
.NEAR TERM /UNTIL 7 AM THURSDAY MORNING/...
AS OF 915 PM WEDNESDAY...
...A NEW TORNADO WATCH THAT WILL BE IN EFFECT THROUGH 400 AM HAS
REPLACED THE PREVIOUS ONE THAT WAS IN EFFECT THROUGH 900 PM...
THE SEVERE WEATHER PARAMETERS ARE MARGINALLY FAVORABLE FOR THE NEW
TORNADO WATCH. THE MOST FAVORABLE PARAMETERS SEEM TO BE SHIFTING
NORTHWARD... FOCUSING FROM NORTHERN NC INTO VA WHERE THE 0-1KM STORM
RELATIVE HELICITIES WERE GREATEST (250-350 M2/S2). HOWEVER... THE
SURFACE BASED AND 100 MB MIXED LAYER CAPES HAVE BEEN LESSENING WITH
LOSS OF HEATING... AND HAVE BEEN SHIFTING TO THE EASTERN PIEDMONT
AND WESTERN COASTAL PLAIN REGIONS.
THE LATEST WATER VAPOR SATELLITE IMAGERY INDICATED THE MID LEVEL LOW
WAS OVER WESTERN KENTUCKY MOVING EAST. AT LEAST SOME SCATTERED
THUNDERSTORMS ARE EXPECTED ACROSS NC OVERNIGHT AS LARGE SCALE
LIFTING INCREASES AHEAD OF THIS SYSTEM PER THE CURRENT ACTIVITY OVER
THE MOUNTAINS. THE DEEP LAYER SHEAR IS EXPECTED TO INCREASE TO
40-45KT OVERNIGHT. THE MOIST BOUNDARY LAYER AND UP TO 30KT OF LOW
LEVEL SHEAR SUGGEST THAT ISOLATED TORNADOES MAY CONTINUE TO BE THE
MAIN THREAT IN ANY STRONG CONVECTION.
THE RADAR TRENDS HAVE BEEN SHOWING A DECREASE IN THE CONVECTIVE
ACTIVITY SINCE 730 PM OVER CENTRAL NC.... WITH EVEN THE BOWING LINE
THAT WAS PUSHING INTO OUR SW PIEDMONT AROUND ALBEMARLE DIMINISHING
IN INTENSITY AS WELL. IT APPEARS THAT THIS COULD CHANGE IN THE NEXT
FEW HOURS AS THE LARGE SCALE LIFT INCREASES FROM THE WEST.
THERE HAS BEEN A GOOD AMOUNT OF SHOWERS WITH EMBEDDED THUNDERSTORMS
DEVELOPING AND EXPANDING ACROSS THE NC MOUNTAINS. AS THIS COMES
EAST... WE WILL SEE IF WE CAN GET ANYTHING UP CLOSE TO SEVERE OVER
THE TRIAD REGION IN THE NEXT FEW HOURS. WE WILL RAISE POP TO NEAR
CATEGORICAL OVER THE WEST TO ACCOUNT FOR THE ACTIVITY DEVELOPING
OVER THE MOUNTAINS AND PUSHING INTO THE PIEDMONT THROUGH THE LATE
EVENING. WE WILL BRING THIS ACTIVITY EASTWARD ACROSS OUR REGION
OVERNIGHT.
NO OTHER CHANGES AT THIS TIME.
&&
.SHORT TERM /7 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
AS OF 310 PM WEDNESDAY...
EXPECT ONGOING CONVECTION EAST OF HIGHWAY 1 TO EXIT REGION AFTER
15Z. APPEARS THAT AIR MASS WILL BE ABLE TO RECOVER AND SUPPORT
SCATTERED STRONG CONVECTION AFTER 19Z OVER ALL BUT THE FAR NW.
EXPECT CLOUDS EARLY THU TO SCATTERED OUT BY LATE MORNING...ENABLING
TEMPS TO SOAR TO NEAR 80/LOWER 80S BY EARLY AFTERNOON. WHILE LOW
LEVEL AIRMASS WILL BE QUITE UNSTABLE...WIND FIELD ALOFT AND MID
LEVEL LAPSE RATES SUGGEST THAT SEVERE STORMS SHOULD BE FEW IN NUMBER
AND CONSISTENT OF LARGE HAIL AND DAMAGING WIND GUSTS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
AS OF 340 PM WEDNESDAY...
A SURFACE BOUNDARY MOVING EAST THROUGH CENTRAL NORTH CAROLINA
THURSDAY NIGHT INTO EARLY FRIDAY MORNING WILL TAKE THE CHANCE FOR
RAIN WITH IT. LOWS THURSDAY NIGHT WILL BE IN THE LOW TO MID 60S.
HIGHS FRIDAY WILL BE IN THE 80S.
THE BREAK IN THE RAIN WILL BE SHORT LIVED AS UNSETTLED WEATHER WILL
TAKE OVER IN RESPONSE TO A SERIES OF SURFACE WAVES IN CONJUNCTION
WITH UPPER LEVEL DISTURBANCES MOVING THROUGH WESTERLY FLOW ALOFT
FRIDAY NIGHT THROUGH MONDAY NIGHT. PWAT VALUES THROUGH THIS PERIOD
WILL BE IN EXCESS OF ONE INCH. LOWS FRIDAY AND SATURDAY NIGHT WILL
BE IN THE 60S... COOLING TO THE 50S FOR THE FIRST OF NEXT WEEK.
HIGHS SATURDAY IN THE 80S WILL DROP TO THE 70S BY MONDAY.
HIGH PRESSURE WILL BUILD OVER CENTRAL NORTH CAROLINA FROM THE
NORTHWEST TUESDAY INTO WEDNESDAY. HIGHS TUESDAY AND WEDNESDAY WILL
BE IN THE 70S. LOWS TUESDAY NIGHT WILL BE IN THE 50S.
&&
.AVIATION /01Z THURSDAY THROUGH MONDAY/...
AS OF 750 PM WEDNESDAY...
MVFR CEILINGS IN ISOLATED SHOWERS/THUNDERSTORMS WILL CONTINUE OVER
THE NORTHWEST AND THE EAST THROUGH 02-03Z. THE PRECIPITATION MAY
REDEVELOP OVER THE AREA AFTER MIDNIGHT THROUGH EARLY THURSDAY
MORNING AS UPPER LEVEL DISTURBANCES INTERACT WITH A SURFACE BOUNDARY
(SEABREEZE FRONT). LINGERING LOW LEVEL MOISTURE WILL LEAD TO IFR
CEILINGS FROM 10Z TO AROUND NOON ...THAN CEILINGS WILL
LIFT/DISSIPATE AROUND 35 HUNDRED FEET DURING THE AFTERNOON. -RHJ
TRANQUIL WEATHER EXPECTED THURSDAY NIGHT AND FRIDAY MORNING WITH
POCKETS OF MVFR FOG ANTICIPATED.
UNSETTLED WEATHER EXPECTED FRIDAY NIGHT THROUGH MONDAY AS A COLD
FRONT APPROACHES THEN STALLS IN OUR VICINITY. -WSS
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BADGETT
NEAR TERM...BADGETT/RHJ
SHORT TERM...BL
LONG TERM...BADGETT/RHJ
AVIATION...RHJ
000
FXUS62 KRAH 070100
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
900 PM EDT WED MAY 6 2009
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES WILL RESULT IN SEVERAL ROUNDS
OF SCATTERED SHOWERS AND THUNDERSTORMS ACROSS CENTRAL NORTH CAROLINA
THROUGH THURSDAY.
&&
.NEAR TERM /UNTIL 7 AM THURSDAY MORNING/...
AS OF 900 PM WEDNESDAY...
...A NEW TORNADO WATCH THAT WILL BE IN EFFECT THROUGH 400 AM HAS
REPLACED THE PREVIOUS ONE THAT WAS IN EFFECT THROUGH 900 PM...
THE SEVERE WEATHER PARAMETERS ARE MARGINALLY FAVORABLE FOR THE NEW
TORNADO WATCH. THE MOST FAVORABLE PARAMETERS SEEM TO BE SHIFTING
NORTHWARD... FOCUSING FROM NORTHERN NC INTO VA WHERE THE 0-1KM STORM
RELATIVE HELICITIES WERE GREATEST (250-350 M2/S2). HOWEVER... THE
SURFACE BASED AND 100 MB MIXED LAYER CAPES HAVE BEEN LESSENING WITH
LOSS OF HEATING... AND HAVE BEEN SHIFTING TO THE EASTERN PIEDMONT
AND WESTERN COASTAL PLAIN REGIONS.
THE RADAR TRENDS HAVE BEEN SHOWING A DECREASE IN THE CONVECTIVE
ACTIVITY SINCE 730 PM.... WITH EVEN THE BOWING LINE THAT WAS PUSHING
INTO OUR SW PIEDMONT AROUND ALBEMARLE DIMINISHING IN INTENSITY AS
WELL. IT APPEARS THAT UNLESS WE GET SOMETHING GOING IN THE NEXT FEW
HOURS THAT WE MAY BE ABLE TO DROP THE WATCH AROUND 1200 AM OR SO.
THERE HAS BEEN A GOOD AMOUNT OF SHOWERS WITH EMBEDDED THUNDERSTORMS
DEVELOPING AND EXPANDING ACROSS THE NC MOUNTAINS. AS THIS COMES
EAST... WE WILL SEE IF WE CAN GET ANYTHING UP CLOSE TO SEVERE OVER
THE TRIAD REGION IN THE NEXT FEW HOURS. WE WILL RAISE POP TO NEAR
CATEGORICAL OVER THE WEST TO ACCOUNT FOR THE ACTIVITY DEVELOPING
OVER THE MOUNTAINS AND PUSHING INTO THE PIEDMONT THROUGH THE LATE
EVENING. WE WILL BRING THIS ACTIVITY EASTWARD ACROSS OUR REGION
OVERNIGHT.
NO OTHER CHANGES AT THIS TIME.
&&
.SHORT TERM /7 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
AS OF 310 PM WEDNESDAY...
EXPECT ONGOING CONVECTION EAST OF HIGHWAY 1 TO EXIT REGION AFTER
15Z. APPEARS THAT AIR MASS WILL BE ABLE TO RECOVER AND SUPPORT
SCATTERED STRONG CONVECTION AFTER 19Z OVER ALL BUT THE FAR NW.
EXPECT CLOUDS EARLY THU TO SCATTERED OUT BY LATE MORNING...ENABLING
TEMPS TO SOAR TO NEAR 80/LOWER 80S BY EARLY AFTERNOON. WHILE LOW
LEVEL AIRMASS WILL BE QUITE UNSTABLE...WIND FIELD ALOFT AND MID
LEVEL LAPSE RATES SUGGEST THAT SEVERE STORMS SHOULD BE FEW IN NUMBER
AND CONSISTENT OF LARGE HAIL AND DAMAGING WIND GUSTS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
AS OF 340 PM WEDNESDAY...
A SURFACE BOUNDARY MOVING EAST THROUGH CENTRAL NORTH CAROLINA
THURSDAY NIGHT INTO EARLY FRIDAY MORNING WILL TAKE THE CHANCE FOR
RAIN WITH IT. LOWS THURSDAY NIGHT WILL BE IN THE LOW TO MID 60S.
HIGHS FRIDAY WILL BE IN THE 80S.
THE BREAK IN THE RAIN WILL BE SHORT LIVED AS UNSETTLED WEATHER WILL
TAKE OVER IN RESPONSE TO A SERIES OF SURFACE WAVES IN CONJUNCTION
WITH UPPER LEVEL DISTURBANCES MOVING THROUGH WESTERLY FLOW ALOFT
FRIDAY NIGHT THROUGH MONDAY NIGHT. PWAT VALUES THROUGH THIS PERIOD
WILL BE IN EXCESS OF ONE INCH. LOWS FRIDAY AND SATURDAY NIGHT WILL
BE IN THE 60S... COOLING TO THE 50S FOR THE FIRST OF NEXT WEEK.
HIGHS SATURDAY IN THE 80S WILL DROP TO THE 70S BY MONDAY.
HIGH PRESSURE WILL BUILD OVER CENTRAL NORTH CAROLINA FROM THE
NORTHWEST TUESDAY INTO WEDNESDAY. HIGHS TUESDAY AND WEDNESDAY WILL
BE IN THE 70S. LOWS TUESDAY NIGHT WILL BE IN THE 50S.
&&
.AVIATION /01Z THURSDAY THROUGH MONDAY/...
AS OF 750 PM WEDNESDAY...
MVFR CEILINGS IN ISOLATED SHOWERS/THUNDERSTORMS WILL CONTINUE OVER
THE NORTHWEST AND THE EAST THROUGH 02-03Z. THE PRECIPITATION MAY
REDEVELOP OVER THE AREA AFTER MIDNIGHT THROUGH EARLY THURSDAY
MORNING AS UPPER LEVEL DISTURBANCES INTERACT WITH A SURFACE BOUNDARY
(SEABREEZE FRONT). LINGERING LOW LEVEL MOISTURE WILL LEAD TO IFR
CEILINGS FROM 10Z TO AROUND NOON ...THAN CEILINGS WILL
LIFT/DISSIPATE AROUND 35 HUNDRED FEET DURING THE AFTERNOON. -RHJ
TRANQUIL WEATHER EXPECTED THURSDAY NIGHT AND FRIDAY MORNING WITH
POCKETS OF MVFR FOG ANTICIPATED.
UNSETTLED WEATHER EXPECTED FRIDAY NIGHT THROUGH MONDAY AS A COLD
FRONT APPROACHES THEN STALLS IN OUR VICINITY. -WSS
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BADGETT
NEAR TERM...BADGETT/RHJ
SHORT TERM...BL
LONG TERM...BADGETT/RHJ
AVIATION...RHJ
000
FXUS62 KRAH 062359
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
750 PM EDT WED MAY 6 2009
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES WILL RESULT IN SEVERAL ROUNDS
OF SCATTERED SHOWERS AND THUNDERSTORMS ACROSS CENTRAL NORTH CAROLINA
THROUGH THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 245 PM WEDNESDAY...
AIR MASS HAS BECOME MODERATELY UNSTABLE AS HEATING OF MOIST AIR MASS
HAS RESULTED IN SURFACE LIFTED INDICES IN THE MINUS 4 THROUGH MINUS
6 OVER ALL BUT THE EXTREME NW PIEDMONT. SURFACE BOUNDARY HAS LIFTED
NORTH OF THE TRIAD AS DEWPOINTS THERE HAVE JUMPED INTO THE MID 60S
AND WINDS VEERED TO A SLY DIRECTION. APPROACH OF MCV CURRENTLY OVER
NORTHERN GA WILL INCREASE THE MID LEVEL BULK SHEAR BY 20-21Z ACROSS
THE REGION. CURRENT RANDOM NATURE OF CELLS SHOULD BECOME BETTER
ORGANIZED SHORTLY OVER THE WESTERN AND SOUTHERN PIEDMONT WITH
APPROACH OF MCV. TORNADIC THREAT APPEARS TO BE GREATEST NORTH OF
HIGHWAY 64...MORE SO NEAR THE VA BORDER AND IN THE VICINITY OF THE
TRIAD.
NEAR TERM MODELS HAVING A DIFFICULT TIME CONCERNING PLACEMENT/TIMING
OF OTHER MCV APPROACHING FROM THE WEST-SW. MODELS TOO FAR NORTH WITH
ACTIVITY NOW OCCURRING ACROSS THE DEEP SOUTH. STILL...APPEARS THAT
LOW LEVEL CONFLUENCE WILL INCREASE AFTER 00Z. MID LEVEL LAPSE RATES
NOT IMPRESSIVE BUT OVERNIGHT SURFACE BASED CAPES PROGGED TO REMAIN
BETWEEN 500-1000J/KG OVER THE PIEDMONT. MAY SEE 0-3KM BULK SHEAR
RECOVER AFTER 06Z TO 35-40KTS. THUS...MAY SEE CONVECTION WANE/WEAKEN
AFTER 00Z...THEN REDEVELOPMENT LATE TONIGHT/AFTER MIDNIGHT IN THE
WEST AND PROGRESS EAST DURING THE OVERNIGHT. SINCE SOME PARAMETERS
FAVOR SEVERE AND OTHERS RATHER WEAK...NOT ANTICIPATING A WIDESPREAD
SEVERE EVENT BUT CANNOT RULE OUT A SEVERE STORM OR TWO ACROSS THE
REGION AFTER 06Z.
&&
.SHORT TERM /THURSDAY/...
AS OF 310 PM WEDNESDAY...
EXPECT ONGOING CONVECTION EAST OF HIGHWAY 1 TO EXIT REGION AFTER
15Z. APPEARS THAT AIR MASS WILL BE ABLE TO RECOVER AND SUPPORT
SCATTERED STRONG CONVECTION AFTER 19Z OVER ALL BUT THE FAR NW.
EXPECT CLOUDS EARLY THU TO SCATTERED OUT BY LATE MORNING...ENABLING
TEMPS TO SOAR TO NEAR 80/LOWER 80S BY EARLY AFTERNOON. WHILE LOW
LEVEL AIRMASS WILL BE QUITE UNSTABLE...WIND FIELD ALOFT AND MID
LEVEL LAPSE RATES SUGGEST THAT SEVERE STORMS SHOULD BE FEW IN NUMBER
AND CONSISTENT OF LARGE HAIL AND DAMAGING WIND GUSTS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
AS OF 340 PM WEDNESDAY...
A SURFACE BOUNDARY MOVING EAST THROUGH CENTRAL NORTH CAROLINA
THURSDAY NIGHT INTO EARLY FRIDAY MORNING WILL TAKE THE CHANCE FOR
RAIN WITH IT. LOWS THURSDAY NIGHT WILL BE IN THE LOW TO MID 60S.
HIGHS FRIDAY WILL BE IN THE 80S.
THE BREAK IN THE RAIN WILL BE SHORT LIVED AS UNSETTLED WEATHER WILL
TAKE OVER IN RESPONSE TO A SERIES OF SURFACE WAVES IN CONJUNCTION
WITH UPPER LEVEL DISTURBANCES MOVING THROUGH WESTERLY FLOW ALOFT
FRIDAY NIGHT THROUGH MONDAY NIGHT. PWAT VALUES THROUGH THIS PERIOD
WILL BE IN EXCESS OF ONE INCH. LOWS FRIDAY AND SATURDAY NIGHT WILL
BE IN THE 60S... COOLING TO THE 50S FOR THE FIRST OF NEXT WEEK.
HIGHS SATURDAY IN THE 80S WILL DROP TO THE 70S BY MONDAY.
HIGH PRESSURE WILL BUILD OVER CENTRAL NORTH CAROLINA FROM THE
NORTHWEST TUESDAY INTO WEDNESDAY. HIGHS TUESDAY AND WEDNESDAY WILL
BE IN THE 70S. LOWS TUESDAY NIGHT WILL BE IN THE 50S.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 750 PM WEDNESDAY...
MVFR CEILINGS IN ISOLATED SHOWERS/THUNDERSTORMS WILL CONTINUE OVER
THE NORTHWEST AND THE EAST THROUGH 02-03Z. THE PRECIPITATION MAY
REDEVELOP OVER THE AREA AFTER MIDNIGHT THROUGH EARLY THURSDAY
MORNING AS UPPER LEVEL DISTURBANCES INTERACT WITH A SURFACE BOUNDARY
(SEABREEZE FRONT). LINGERING LOW LEVEL MOISTURE WILL LEAD TO IFR
CEILINGS FROM 10Z TO AROUND NOON ...THAN CEILINGS WILL
LIFT/DISSIPATE AROUND 35 HUNDRED FEET DURING THE AFTERNOON. -RHJ
TRANQUIL WEATHER EXPECTED THURSDAY NIGHT AND FRIDAY MORNING WITH
POCKETS OF MVFR FOG ANTICIPATED.
UNSETTLED WEATHER EXPECTED FRIDAY NIGHT THROUGH MONDAY AS A COLD
FRONT APPROACHES THEN STALLS IN OUR VICINITY. -WSS
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS
SHORT TERM...CBL
LONG TERM...RHJ
AVIATION...RHJ/WSS
000
FXUS62 KILM 062338
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
737 PM EDT WED MAY 6 2009
.SYNOPSIS...
A LOW TO MID LEVEL TROUGH APPROACHING THE LOCAL AREA TONIGHT WILL
PASS THROUGH ON THURSDAY PRODUCING MORE WIDESPREAD SHOWER AND
THUNDERSTORM ACTIVITY. HOT AND DRIER WEATHER WILL PREVAIL ON
FRIDAY AND SATURDAY AS HIGH PRESSURE NOSES IN FROM THE WEST. A
COLD FRONT WILL MOVE ACROSS THE AREA SATURDAY NIGHT AND SUNDAY
MORNING BRINGING DRIER AIR FOR THE EARLY PART OF NEXT WEEK AS HIGH
PRESSURE BUILDS INTO THE REGION FROM THE NORTH THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM WEDNESDAY...DRIER AIR HAS OVERSPREAD THE FORECAST AREA
THROUGH THE AFTERNOON HOURS...LIMITING THE AMOUNT OF CONVECTION WITH
CUMULUS FIELDS FAIRLY SHALLOW. STILL...HEATING HAS ALLOWED SHOWERS
AND THUNDERSTORMS TO DEVELOP...ESPECIALLY TO OUR N AND NW. SOME OF
THESE STORMS WILL PROPAGATE INTO THE PEE DEE REGION OF SC AND
PERHAPS NORTHWARD INTO ROBESON COUNTY. THE RISK FOR AN ISOLATED
STRONG TO SEVERE WIND GUST OR HAIL CAN NOT BE RULED OUT WITH THESE
STORMS. AS THESE STORMS ARE WINDING DOWN THIS EVE...A LARGE BATCH OF
SHOWERS AND THUNDERSTORMS IS EXPECTED TO SURVIVE THEIR TREK OVER THE
MOUNTAINS...AS LOW LEVEL SW JET INCREASES TO 40-45 KT OVERNIGHT.
THESE THUNDERSTORMS WILL MOVE INTO THE FORECAST AREA LATER THIS EVE
AND PERSIST THROUGH THE NIGHTTIME AND MORNING HOURS OF THU. THE
TRIGGER FOR THIS ROUND OF CONVECTION WILL BE A RATHER POTENT
MID-LEVEL SHORT WAVE TROUGH EMBEDDED IN INCREASINGLY ZONAL FLOW.
TIMING OF THIS CONVECTION (AFTER AIRMASS STABILIZATION HAS BEGUN) IS
EXPECTED TO LIMIT SEVERE WEATHER RISK. STILL...STRONG THUNDERSTORMS
WITH GUSTY WINDS WILL BE POSSIBLE OVERNIGHT. TRENDED POPS TO
INDICATE GREATEST COVERAGE OF THUNDERSTORMS AND HIGHEST
PROBABILITIES WILL TRAVERSE THE AREA FROM W TO E TONIGHT AND INTO
THU MORNING. TEMPS WILL BE BALMY OVERNIGHT WITH SOUTHERLY WINDS
STAYING UP AND SOME AREAS MAY NOT DIP BELOW 70 DEG...ESPECIALLY
ALONG THE COAST.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...A FAIRLY DECENT SHORTWAVE WILL MOVE THROUGH
ON THURS WITH A RELATIVELY ZONAL FLOW TO FOLLOW AND A LESS
IMPRESSIVE RIPPLE IN THE FLOW LATE FRI. THIS SHORTWAVE WILL
TRANSLATE DOWN THROUGH THE LOWER LEVELS WITH TROUGH MOVING THROUGH
THURS AFTN. EXPECT MOST SHWR/TSTM ACTIVITY TO OCCUR MORE TOWARD
THE BEGINNING OF THE PERIOD AS SHORTWAVE TRAVERSES THE AREA AND
SHOULD TAPER OFF BY THURS EVENING FROM WEST TO EAST. ONCE
SHORTWAVE AND ASSOCIATED LOWER LEVEL TROUGH PASSES ON THURS GFS
SHOWS A NICE DRY PUNCH MOVING IN AS WINDS THROUGH THE LOWER TO MID
LEVELS SHIFT AROUND TO THE W-NW AND WILL MAINTAIN A WESTERLY
COMPONENT THROUGH THE REMAINDER OF THE PERIOD. BY FRI ANY SHOWER
ACTIVITY WILL BE FOCUSED ALONG SEA BREEZE IN THE AFTN AS IT PUSHES
INLAND. THURS WILL DEFINITELY BE THE MORE ACTIVE DAY WITH GFS/NAM
AND SREF SHOWING BEST CHC OF PCP AROUND 12 TO 18Z. MU CAPE WILL BE
UP TO AROUND 2500 J/KG AND PCP WATER VALUES MAXING OUT AROUND 1.7
INCHES THURS MORNING. THE ONE PIECE THAT WILL BE LACKING IS THE
TIMING DOES NOT COINCIDE WITH MAX HEATING.
AS FOR TEMPERATURES THURS WILL REMAIN AROUND CLIMO WITH CLOUDS AND
PCP HOLDING IT DOWN A BIT. FRI AFTN TEMPS SHOULD SOAR THROUGH THE
80S WITH SUNSHINE AND FEWER SHWRS EXPECTED AS WELL AS A MORE
WESTERLY FLOW THROUGH THE LOWER LEVELS OF THE ATMOSPHERE. TEMPS AT
NIGHT WILL REMAIN ABOVE NORMAL IN THE MID 60S MOST PLACES.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 3 PM WEDNESDAY...SLIGHT PATTERN SHIFT AS FLAT UPPER RIDGE IS
SUPPRESSED TO THE SOUTH AFTER THE WEEKEND. ONE MORE WARM DAY ON
SATURDAY WITH TEMPS NEAR 90 AWAY FROM THE IMMEDIATE COAST...BUT THE
FRONT AND UPPER DISTURBANCES WILL BE CLOSE ENOUGH TO WARRANT SLIGHT
CHANCE POPS. FRONT MOVES THROUGH SAT NIGHT AND SUNDAY...BUT COULD
REMAIN UNSETTLED INTO MONDAY DEPENDING ON THE VALIDITY OF UPPER
DISTURBANCES ADVERTISED BY GFS. WILL HOLD LOW CHANCE POPS IN FOR
MONDAY. DRIER HIGH PRESSURE RIDGING INTO THE CAROLINAS FROM THE
NORTH WILL KEEP TEMPS NEAR OR SLIGHTLY BELOW SEASONAL NORMALS
TUE-WED.
&&
.AVIATION /00Z WEDNESDAY THROUGH MONDAY/...
A STATIONARY FRONT LOCATED ALONG THE VIRGINIA-NORTH CAROLINA EXTENDS
SOUTHWEST TO NEAR KHKY AND THE FRONT WILL CONTINUE TO REMAIN NORTH
OF THE TAF SITES THIS FORECAST PERIOD. A SQUALL LINE IN WESTERN
SOUTH CAROLINA IS EXPECTED TO CONTINUE ITS EASTERN PUSH AND SHOULD
IMPACT THE KLBT AND KFLO TAF SITES AROUND 02 UTC AND THE COASTAL TAF
SITES BETWEEN 03 AND 04 UTC.
CONDITIONS CONTINUE FOR A MODERATELY UNSTABLE REGION WITH RIPPLES OF
SHORT WAVE ENERGY MOVING WEST TO EAST ACROSS THE AREA. TIMING OF
THESE WAVES WILL BE KEY IN THE TIME OF THE FORECAST. WILL MAINTAIN
VFR CONDITIONS WITH MVFR IMPACTS WITH THUNDERSTORMS. AT THIS TIME
WILL REFRAIN FROM MENTION OF THE IFR.
EXTENDED OUTLOOK THROUGH MONDAY...SCATTERED THUNDERSTORMS THURSDAY
AND SUNDAY. ISOLATED THUNDERSTORMS FRIDAY AND SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM WEDNESDAY...AS SW LOW LEVEL JET INCREASES TONIGHT...
EXPECT WINDS WILL PICK UP ACROSS THE WATERS AS ENVIRONMENT BECOMES
INCREASINGLY WELL MIXED. PRESSURE GRADIENT WILL TIGHTEN UP ACROSS
THE WATERS...ESPECIALLY AFTER MIDNIGHT. SE SWELL...PERIODS OF 9/10
SEC WILL PERSIST THIS PERIOD...CONTRIBUTING TO WAVE HEIGHTS. THAT
BEING SAID...MARGINAL SMALL CRAFT CONDITIONS ARE EXPECTED TO
MATERIALIZE AFTER MIDNIGHT ACROSS THE WATERS FROM LITTLE RIVER INLET
TO SURF CITY AND TO PERSIST INTO THU NIGHT. FURTHER S...WILL KEEP
CONDITIONS JUST BELOW ADVISORY CRITERIA. SMALL CRAFT SHOULD EXERCISE
CAUTION WILL BE HEADLINED FROM LITTLE RIVER INLET TO THE SOUTH
SANTEE RIVER...BEGINNING AFTER MIDNIGHT.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...SOUTHERLY WINDS EXPECTED THROUGH MOST OF
THE PERIOD. WILL START OUT WITH A GOOD 15 TO 20 KTS ON THURS WHICH
WILL PUSH SEAS INTO SCA CRITERIA FOR THE NORTHERN 2 ZONES. SCA
WILL BASICALLY RUN UP THROUGH MIDNIGHT THURS INTO FRI. OTHERWISE
SEAS WILL REMAIN IN THE 3 TO 5 FT RANGE MOST WATERS. WINDS TAKE ON
A MORE WESTERLY COMPONENT FOR A SHORT TIME LATE THURS AFTER
SHORTWAVE MOVES THROUGH.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 PM WEDNESDAY...MODEST SW FLOW WILL CARRY THROUGH SATURDAY
INTO SAT NIGHT...WITH SPEEDS 15-20 KT AHEAD OF THE APPROACHING
FRONT. FULLY DEVELOPED SEAS AT THAT POINT WILL BE KNOCKING ON THE
DOOR OF SCA...BUT FOR NOW WILL KEEP 3-5 FT IN THE OFFICIAL FORECAST.
FRONT DROPS THROUGH ON SUNDAY MORNING...WITH A WIND SHIFT TO THE
NORTH. NOT MUCH OF A SURGE BEHIND THE FRONT GIVEN WEAK CAA AND THE
RELUCTANCE OF THE HIGH PRESSURE TO BUILD IN. WIND SPEEDS WILL BE
10-15 KT THROUGH MONDAY...WITH SEAS SUBSIDING TO AROUND 2 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 AM THURSDAY TO 2 AM EDT FRIDAY FOR
AMZ250-252.
&&
$$
SYNOPSIS...RGZ
NEAR TERM...RJD
SHORT TERM...RGZ
LONG TERM...RAS
AVIATION...HAWKINS
000
FXUS62 KMHX 061946
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
346 PM EDT WED MAY 6 2009
.SYNOPSIS...
HIGH PRESSURE OVER AREA TONIGHT THROUGH SATURDAY. FRONT TO MOVE
THROUGH NC SATURDAY NIGHT. HIGH PRESSURE WILL BUILD BACK IN SUNDAY
NIGHT.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
WL BE INTERESTING TO SEE WHAT HAPPENS OVR NGT TNGT. SHWRS CONT TO MV
NE THRU CWA ALNG THE CSTL PLAINS AREAS. VIS SAT PIX SHOWG PSBL CBRZ
FORMATION THIS AFTN. THIS MAY HELP SPPRS ACTVTY OVR ONSLOW AND
CARTERET CNTYS. ALL MDLS SHOWG A LULL IN ACTVTY THIS EVE AS UPR LVLS
LACKG MUCH ENERGY. NXT PIECE OF ENERGY WL SWING THRU LT TNGT WI AN
INCRS IN POPS STRTG ARND 7Z.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
UNSTTLD WX WL CONT THRU THE RMNDR OF THE WK AS UPR TROF SLOWLY
APPRCHS FRM THE W. MDLS SHOWG UPR TROF MVS THRU AREA THU NGT. LWR
MSTR AND LACK OF UPR LVL ENERGY ON FRI SHUD HELP KP THE DAY DRY.
ANTHR S/WV MVS THRU THE FLO FRI NGT. DOESNT APPR TO HV TOO MUCH MSTR
WI THIS. ANTHR SYS APPCHS IN THE FAST FLO APPRCHS SAT WI A WK UPR
LVL S/WV SO WL HV LO POPS SAT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
FRNT TO MV THRU AREA SAT NGT WI LO LVL FLO BCMG NLY. ANTHR SURGE
APPRS TO DROP THRU AND DISSIPATE SUNDAY NGT. STL RMNG IN ZNL FLO
ALFT WI WK S/WVS ZIPPG THRU THE FLO. THIS WL KP A CHC OF SHWRS OVR
CWA THRU FIRST PART OF THE WK. UPR RDG TO BLD IN ON TUE WI SFC RDG
BLDG DWN FRM THE N.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
SCATTERED STRONG CONVECTION EXPECTED THROUGH THIS EVENING MAINLY
VICINITY OF KISO/KPGV. FOLLOWING THE NAM MODEL BRINGS IN
WIDESPREAD CONVECTION AFTER 08Z TONIGHT THROUGH 16Z THURSDAY THEN
ISOLATED THURSDAY AFTERNOON/EVENING. THUS WILL INTRODUCE
PREVAILING MVFR CONDITIONS LATE TONIGHT THROUGH 16-17Z THURSDAY.
FORECAST THROUGH SUNDAY WILL FEATURE WARM SECTOR CONDITIONS WITH
MAINLY AFTERNOON/EVENING SHOWERS AND STORMS. LOOKS LIKE A DRYING
COOL FRONT WILL PUSH SOUTH OF THE AREA MONDAY WITH A LULL IN THE
PRECIPITATION PATTERN EXPECTED.
&&
.MARINE...
ACTIVE PATTERN THE NEXT SEVERAL DAYS WILL PRODUCE SHORT PERIOD
STEEP WIND WAVES AND SW WINDS 20-25 KT THROUGH SATURDAY EVENING
PROMPTING THE ISSUANCE OF SMALL CRAFT ADVISORIES FOR ALL THE
WATERS. THE ADVISORY CONDITIONS COULD BEGIN TO EASE SUNDAY
EVENING AS A FRONT DRIFTS SOUTH OF THE WATERS.
SW FLOW WILL INCREASE THIS EVENING AS LOW LEVEL JET MOVES OVER THE
AREA IN ADVANCE OF A SHORT WAVE TROUGH ALOFT. A QUASI-STATIONARY
FRONT WILL REMAIN JUST TO THE WEST OF THE WATERS THROUGH SUNDAY.
SEVERAL SHORTWAVE TROUGHS WILL INTERACT WITH THE BOUNDARY
PRODUCING WEAK FRONTAL WAVES WHICH WILL ENHANCE THE SW FLOW AND
PRODUCE WINDS AROUND 25 KT AND SEAS 6-8 FT. THE FRONT IS EXPECTED
TO FINALLY SINK SOUTH OF THE WATERS SUNDAY EVENING WITH THE FLOW
TURNING TO NE. THE NEW GFS AND ECMWF ARE STRONGER WITH THE POST
FRONTAL NE FLOW (20 KT) INDICATING A CONTINUATION OF ADVISORY OF
NEAR ADVISORY CONDITIONS FROM CAPE LOOKOUT TO OREGON INLET. THE
EXTREME NORTHERN AND SOUTHERN WATERS MAY IMPROVE BELOW ADVISORY
CRITERIA MONDAY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM TO 2 PM EDT THURSDAY FOR AMZ130-
135.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT SUNDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT SUNDAY FOR AMZ156-158.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT THURSDAY FOR AMZ150.
&&
$$
SYNOPSIS...CGG
NEAR TERM...CGG
SHORT TERM...CGG
LONG TERM...CGG
AVIATION...JME
MARINE...JME
000
FXUS62 KRAH 061942
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
340 PM EDT WED MAY 6 2009
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES WILL BRING CAUSE SEVERAL ROUNDS
OF SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE AREA THROUGH
THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 245 PM WEDNESDAY...
AIR MASS HAS BECOME MODERATELY UNSTABLE AS HEATING OF MOIST AIR MASS
HAS RESULTED IN SURFACE LIFTED INDICES IN THE MINUS 4 THROUGH MINUS
6 OVER ALL BUT THE EXTREME NW PIEDMONT. SURFACE BOUNDARY HAS LIFTED
NORTH OF THE TRIAD AS DEWPOINTS THERE HAVE JUMPED INTO THE MID 60S
AND WINDS VEERED TO A SLY DIRECTION. APPROACH OF MCV CURRENTLY OVER
NORTHERN GA WILL INCREASE THE MID LEVEL BULK SHEAR BY 20-21Z ACROSS
THE REGION. CURRENT RANDOM NATURE OF CELLS SHOULD BECOME BETTER
ORGANIZED SHORTLY OVER THE WESTERN AND SOUTHERN PIEDMONT WITH
APPROACH OF MCV. TORNADIC THREAT APPEARS TO BE GREATEST NORTH OF
HIGHWAY 64...MORE SO NEAR THE VA BORDER AND IN THE VICINITY OF THE
TRIAD.
NEAR TERM MODELS HAVING A DIFFICULT TIME CONCERNING PLACEMENT/TIMING
OF OTHER MCV APPROACHING FROM THE WEST-SW. MODELS TOO FAR NORTH WITH
ACTIVITY NOW OCCURRING ACROSS THE DEEP SOUTH. STILL...APPEARS THAT
LOW LEVEL CONFLUENCE WILL INCREASE AFTER 00Z. MID LEVEL LAPSE RATES
NOT IMPRESSIVE BUT OVERNIGHT SURFACE BASED CAPES PROGGED TO REMAIN
BETWEEN 500-1000J/KG OVER THE PIEDMONT. MAY SEE 0-3KM BULK SHEAR
RECOVER AFTER 06Z TO 35-40KTS. THUS...MAY SEE CONVECTION WANE/WEAKEN
AFTER 00Z...THEN REDEVELOPMENT LATE TONIGHT/AFTER MIDNIGHT IN THE
WEST AND PROGRESS EAST DURING THE OVERNIGHT. SINCE SOME PARAMETERS
FAVOR SEVERE AND OTHERS RATHER WEAK...NOT ANTICIPATING A WIDESPREAD
SEVERE EVENT BUT CANNOT RULE OUT A SEVERE STORM OR TWO ACROSS THE
REGION AFTER 06Z.
&&
.SHORT TERM /THURSDAY/...
AS OF 310 PM WEDNESDAY...
EXPECT ONGOING CONVECTION EAST OF HIGHWAY 1 TO EXIT REGION AFTER
15Z. APPEARS THAT AIR MASS WILL BE ABLE TO RECOVER AND SUPPORT
SCATTERED STRONG CONVECTION AFTER 19Z OVER ALL BUT THE FAR NW.
EXPECT CLOUDS EARLY THU TO SCATTERED OUT BY LATE MORNING...ENABLING
TEMPS TO SOAR TO NEAR 80/LOWER 80S BY EARLY AFTERNOON. WHILE LOW
LEVEL AIRMASS WILL BE QUITE UNSTABLE...WIND FIELD ALOFT AND MID
LEVEL LAPSE RATES SUGGEST THAT SEVERE STORMS SHOULD BE FEW IN NUMBER
AND CONSISTENT OF LARGE HAIL AND DAMAGING WIND GUSTS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
AS OF 340 PM WEDNESDAY...
A SURFACE BOUNDARY MOVING EAST THROUGH CENTRAL NORTH CAROLINA
THURSDAY NIGHT INTO EARLY FRIDAY MORNING WILL TAKE THE CHANCE FOR
RAIN WITH IT. LOWS THURSDAY NIGHT WILL BE IN THE LOW TO MID 60S.
HIGHS FRIDAY WILL BE IN THE 80S.
THE BREAK IN THE RAIN WILL BE SHORT LIVED AS UNSETTLED WEATHER WILL
TAKE OVER IN RESPONSE TO A SERIES OF SURFACE WAVES IN CONJUNCTION
WITH UPPER LEVEL DISTURBANCES MOVING THROUGH WESTERLY FLOW ALOFT
FRIDAY NIGHT THROUGH MONDAY NIGHT. PWAT VALUES THROUGH THIS PERIOD
WILL BE IN EXCESS OF ONE INCH. LOWS FRIDAY AND SATURDAY NIGHT WILL
BE IN THE 60S... COOLING TO THE 50S FOR THE FIRST OF NEXT WEEK.
HIGHS SATURDAY IN THE 80S WILL DROP TO THE 70S BY MONDAY.
HIGH PRESSURE WILL BUILD OVER CENTRAL NORTH CAROLINA FROM THE
NORTHWEST TUESDAY INTO WEDNESDAY. HIGHS TUESDAY AND WEDNESDAY WILL
BE IN THE 70S. LOWS TUESDAY NIGHT WILL BE IN THE 50S.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 1158 AM WEDNESDAY...
AREA OF LIFR/IFR CEILINGS AND VISIBILITY NORTH OF A STALLED SURFACE
BOUNDARY WILL SLOWLY LIFT/IMPROVE AS INSOLATION HEATS AIRMASS.
ELSEWHERE...MVFR/VFR CEILINGS EXPECTED THROUGH 02Z WITH BASES
VARYING BETWEEN 2500-4000FT. AFTERNOON HEATING WILL INITIALLY
TRIGGER SCATTERED SHOWERS AND STORMS...MAINLY OVER THE SOUTHERN AND
EASTERN COUNTIES WHERE HEATING HAS BEEN OCCURRING SINCE 10 AM.
SHOWERS AND STORMS EXPECTED TO BECOME MORE NUMEROUS AFTER 21Z. MAY
SEE CONVECTION WANE A BIT BY 00Z BUT EXPECTED TO REINVIGORATE AFTER
03Z AS SIGNIFICANT UPPER LEVEL DISTURBANCE CROSSES NEAR OUR AREA.
CLOUD BASES EXPECTED TO VARY WIDELY ACROSS REGION AFTER 00Z WITH
BASES AT OR ABOVE 3000FT IN THE SE AROUND KFAY AND KRWI TO NEAR OR
BELOW 1000FT AT KINT AND KGSO.
SCATTERED SHOWERS AND THUNDERSTORMS MAY BE ONGOING ACROSS THE REGION
THURSDAY MORNING. CONVECTION EXPECTED DIMINISH BY LATE MORNING BUT
REDEVELOPMENT OVER THE SANDHILLS AND COASTAL PLAIN AS AIRMASS
BECOMES UNSTABLE DUE TO HEATING.
TRANQUIL WEATHER EXPECTED THURSDAY NIGHT AND FRIDAY MORNING WITH
POCKETS OF MVFR FOG ANTICIPATED.
UNSETTLED WEATHER EXPECTED FRIDAY NIGHT THROUGH MONDAY AS A COLD
FRONT APPROACHES THEN STALLS IN OUR VICINITY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS
SHORT TERM...CBL
LONG TERM...RHJ
AVIATION...WSS
000
FXUS62 KRAH 061920
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
315 PM EDT WED MAY 6 2009
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES WILL BRING CAUSE SEVERAL ROUNDS
OF SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE AREA THROUGH
THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 245 PM WEDNESDAY...
AIR MASS HAS BECOME MODERATELY UNSTABLE AS HEATING OF MOIST AIR MASS
HAS RESULTED IN SURFACE LIFTED INDICES IN THE MINUS 4 THROUGH MINUS
6 OVER ALL BUT THE EXTREME NW PIEDMONT. SURFACE BOUNDARY HAS LIFTED
NORTH OF THE TRIAD AS DEWPOINTS THERE HAVE JUMPED INTO THE MID 60S
AND WINDS VEERED TO A SLY DIRECTION. APPROACH OF MCV CURRENTLY OVER
NORTHERN GA WILL INCREASE THE MID LEVEL BULK SHEAR BY 20-21Z ACROSS
THE REGION. CURRENT RANDOM NATURE OF CELLS SHOULD BECOME BETTER
ORGANIZED SHORTLY OVER THE WESTERN AND SOUTHERN PIEDMONT WITH
APPROACH OF MCV. TORNADIC THREAT APPEARS TO BE GREATEST NORTH OF
HIGHWAY 64...MORE SO NEAR THE VA BORDER AND IN THE VICINITY OF THE
TRIAD.
NEAR TERM MODELS HAVING A DIFFICULT TIME CONCERNING PLACEMENT/TIMING
OF OTHER MCV APPROACHING FROM THE WEST-SW. MODELS TOO FAR NORTH WITH
ACTIVITY NOW OCCURRING ACROSS THE DEEP SOUTH. STILL...APPEARS THAT
LOW LEVEL CONFLUENCE WILL INCREASE AFTER 00Z. MID LEVEL LAPSE RATES
NOT IMPRESSIVE BUT OVERNIGHT SURFACE BASED CAPES PROGGED TO REMAIN
BETWEEN 500-1000J/KG OVER THE PIEDMONT. MAY SEE 0-3KM BULK SHEAR
RECOVER AFTER 06Z TO 35-40KTS. THUS...MAY SEE CONVECTION WANE/WEAKEN
AFTER 00Z...THEN REDEVELOPMENT LATE TONIGHT/AFTER MIDNIGHT IN THE
WEST AND PROGRESS EAST DURING THE OVERNIGHT. SINCE SOME PARAMETERS
FAVOR SEVERE AND OTHERS RATHER WEAK...NOT ANTICIPATING A WIDESPREAD
SEVERE EVENT BUT CANNOT RULE OUT A SEVERE STORM OR TWO ACROSS THE
REGION AFTER 06Z.
&&
.SHORT TERM /THURSDAY/...
AS OF 310 PM WEDNESDAY...
EXPECT ONGOING CONVECTION EAST OF HIGHWAY 1 TO EXIT REGION AFTER
15Z. APPEARS THAT AIR MASS WILL BE ABLE TO RECOVER AND SUPPORT
SCATTERED STRONG CONVECTION AFTER 19Z OVER ALL BUT THE FAR NW.
EXPECT CLOUDS EARLY THU TO SCATTERED OUT BY LATE MORNING...ENABLING
TEMPS TO SOAR TO NEAR 80/LOWER 80S BY EARLY AFTERNOON. WHILE LOW
LEVEL AIRMASS WILL BE QUITE UNSTABLE...WIND FIELD ALOFT AND MID
LEVEL LAPSE RATES SUGGEST THAT SEVERE STORMS SHOULD BE FEW IN NUMBER
AND CONSISTENT OF LARGE HAIL AND DAMAGING WIND GUSTS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
AS OF 340 AM TUESDAY...
ANY REMAINING CONVECTION FROM THURSDAY AFTERNOON SHOULD QUICKLY
DIMINISH DURING THE EVENING WITH THE ONSET OF NOCTURNAL COOLING AND
THE DEPARTURE OF THE MID LEVEL SHORTWAVE. WHILE THE AIRMASS WILL
REMAIN MOIST AND SLIGHTLY UNSTABLE OVERNIGHT...DO NOT SEE ANY
FORCING MECHANISMS AT THIS TIME TO SUPPORT CARRYING POPS PAST THE
EARLY EVENING. IT WILL BE A HUMID AND VERY MILD NIGHT WITH LOWS IN
THE LOW TO MID 60S. PATCHY FOG WILL CERTAINLY BE POSSIBLE GIVEN
DEWPOINTS IN THE 60S AND SOUTHWESTERLY WINDS BECOMING RATHER LIGHT.
THE STATIONARY BOUNDARY OVER THE LOWER MS VALLEY WILL CONTINUE TO
GENERATE WIDESPREAD CONVECTION ACROSS THAT REGION...EXTENDING EAST
INTO THE TN VALLEY ON FRIDAY. IT IS POSSIBLE THAT THIS CONVECTION
COULD GENERATE A MCV THAT THEN TRANSLATES EAST TOWARD OUR REGION
UNDER ZONAL FLOW ALOFT. THE NAM INDICATES THIS IS A POSSIBILITY...
BUT THE GFS AND ECMWF ARE LESS ENTHUSIASTIC. CANNOT HANG OUR HAT ON
THESE POTENTIAL MCVS THIS FAR OUT. SO WITH NO REAL IDENTIFIABLE
TRIGGERS...WE ARE LEFT WITH THE POTENTIAL FOR DIURNALLY DRIVEN
CONVECTION SUPPORTED BY PRECIPITABLE WATERS OVER 1.5 INCHES AND
MLCAPES BETWEEN 1000-2000 J/KG. LOW LEVEL THICKNESSES AND 850 MB
TEMPS SUPPORT HIGHS IN THE 85-88 DEGREE RANGE. WILL KEEP A SLIGHT
CHANCE OF CONVECTION IN THE FORECAST FRIDAY NIGHT GIVEN THE
POTENTIAL FOR A MINOR PERTURBATION TO MOVE THROUGH...INTERACTING
WITH A VERY MOIST AND LINGERING INSTABILITY. LOWS FRI NIGHT 63-67.
A COLD FRONT WILL BEGIN TO APPROACH FROM THE NORTHWEST BY LATE
SATURDAY AFTERNOON AS THE MID LEVEL TROUGH OVER THE GREAT LAKES
BEGINS TO MOVE EAST TOWARD NEW ENGLAND. EXPECT SCATTERED SHOWERS AND
THUNDERSTORMS TO DEVELOP ALONG AND AHEAD OF THE FRONT AS IT
ENCOUNTERS AN UNSTABLE AIRMASS REPRESENTED WITH MLCAPES ABOVE 1000
J/KG. THE BEST MID LEVEL FORCING STAYS WELL TO OUR NORTH...SO WILL
KEEP POPS IN THE CHANCE CATEGORY. THICKNESSES SOAR INTO THE
1410-1415M RANGE...SUPPORTING AT LEAST UPPER 80S FOR HIGHS. WOULD
NOT BE SURPRISED TO SEE SOME LOW 90S IN THE SOUTH AND EAST.
THE FRONT MOVES THROUGH SATURDAY NIGHT WITH A CONTINUED CHANCE FOR
SCATTERED CONVECTION...BUT AS INSTABILITY WANES OVERNIGHT...CHANCES
WILL GRADUALLY DIMINISH. HIGH PRESSURE BEGINS TO BUILD IN FROM THE
NORTH ON SUNDAY...BRINGING A RETURN TO SEASONABLE TEMPS. MODEL
GUIDANCE ALL OVER THE PLACE ON HOW FAR SOUTH THE FRONT MAKES IT AND
ANY POTENTIAL OVERRUNNING PRECIP OVER CENTRAL NC. WILL KEEP THE
FORECAST DRY FOR NOW AND AWAIT A BETTER CONSENSUS.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 1158 AM WEDNESDAY...
AREA OF LIFR/IFR CEILINGS AND VISIBILITY NORTH OF A STALLED SURFACE
BOUNDARY WILL SLOWLY LIFT/IMPROVE AS INSOLATION HEATS AIRMASS.
ELSEWHERE...MVFR/VFR CEILINGS EXPECTED THROUGH 02Z WITH BASES
VARYING BETWEEN 2500-4000FT. AFTERNOON HEATING WILL INITIALLY
TRIGGER SCATTERED SHOWERS AND STORMS...MAINLY OVER THE SOUTHERN AND
EASTERN COUNTIES WHERE HEATING HAS BEEN OCCURRING SINCE 10 AM.
SHOWERS AND STORMS EXPECTED TO BECOME MORE NUMEROUS AFTER 21Z. MAY
SEE CONVECTION WANE A BIT BY 00Z BUT EXPECTED TO REINVIGORATE AFTER
03Z AS SIGNIFICANT UPPER LEVEL DISTURBANCE CROSSES NEAR OUR AREA.
CLOUD BASES EXPECTED TO VARY WIDELY ACROSS REGION AFTER 00Z WITH
BASES AT OR ABOVE 3000FT IN THE SE AROUND KFAY AND KRWI TO NEAR OR
BELOW 1000FT AT KINT AND KGSO.
SCATTERED SHOWERS AND THUNDERSTORMS MAY BE ONGOING ACROSS THE REGION
THURSDAY MORNING. CONVECTION EXPECTED DIMINISH BY LATE MORNING BUT
REDEVELOPMENT OVER THE SANDHILLS AND COASTAL PLAIN AS AIRMASS
BECOMES UNSTABLE DUE TO HEATING.
TRANQUIL WEATHER EXPECTED THURSDAY NIGHT AND FRIDAY MORNING WITH
POCKETS OF MVFR FOG ANTICIPATED.
UNSETTLED WEATHER EXPECTED FRIDAY NIGHT THROUGH MONDAY AS A COLD
FRONT APPROACHES THEN STALLS IN OUR VICINITY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS
SHORT TERM...CBL
LONG TERM...JFB
AVIATION...WSS
000
FXUS62 KILM 061916
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
316 PM EDT WED MAY 6 2009
.SYNOPSIS...
A LOW TO MID LEVEL TROUGH APPROACHING THE LOCAL AREA TONIGHT WILL
PASS THROUGH ON THURSDAY PRODUCING MORE WIDESPREAD SHOWER AND
THUNDERSTORM ACTIVITY. HOT AND DRIER WEATHER WILL PREVAIL ON
FRIDAY AND SATURDAY AS HIGH PRESSURE NOSES IN FROM THE WEST. A
COLD FRONT WILL MOVE ACROSS THE AREA SATURDAY NIGHT AND SUNDAY
MORNING BRINGING DRIER AIR FOR THE EARLY PART OF NEXT WEEK AS HIGH
PRESSURE BUILDS INTO THE REGION FROM THE NORTH THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM WEDNESDAY...DRIER AIR HAS OVERSPREAD THE FORECAST AREA
THROUGH THE AFTERNOON HOURS...LIMITING THE AMOUNT OF CONVECTION WITH
CUMULUS FIELDS FAIRLY SHALLOW. STILL...HEATING HAS ALLOWED SHOWERS
AND THUNDERSTORMS TO DEVELOP...ESPECIALLY TO OUR N AND NW. SOME OF
THESE STORMS WILL PROPAGATE INTO THE PEE DEE REGION OF SC AND
PERHAPS NORTHWARD INTO ROBESON COUNTY. THE RISK FOR AN ISOLATED
STRONG TO SEVERE WIND GUST OR HAIL CAN NOT BE RULED OUT WITH THESE
STORMS. AS THESE STORMS ARE WINDING DOWN THIS EVE...A LARGE BATCH OF
SHOWERS AND THUNDERSTORMS IS EXPECTED TO SURVIVE THEIR TREK OVER THE
MOUNTAINS...AS LOW LEVEL SW JET INCREASES TO 40-45 KT OVERNIGHT.
THESE THUNDERSTORMS WILL MOVE INTO THE FORECAST AREA LATER THIS EVE
AND PERSIST THROUGH THE NIGHTTIME AND MORNING HOURS OF THU. THE
TRIGGER FOR THIS ROUND OF CONVECTION WILL BE A RATHER POTENT
MID-LEVEL SHORT WAVE TROUGH EMBEDDED IN INCREASINGLY ZONAL FLOW.
TIMING OF THIS CONVECTION (AFTER AIRMASS STABILIZATION HAS BEGUN) IS
EXPECTED TO LIMIT SEVERE WEATHER RISK. STILL...STRONG THUNDERSTORMS
WITH GUSTY WINDS WILL BE POSSIBLE OVERNIGHT. TRENDED POPS TO
INDICATE GREATEST COVERAGE OF THUNDERSTORMS AND HIGHEST
PROBABILITIES WILL TRAVERSE THE AREA FROM W TO E TONIGHT AND INTO
THU MORNING. TEMPS WILL BE BALMY OVERNIGHT WITH SOUTHERLY WINDS
STAYING UP AND SOME AREAS MAY NOT DIP BELOW 70 DEG...ESPECIALLY
ALONG THE COAST.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...A FAIRLY DECENT SHORTWAVE WILL MOVE THROUGH
ON THURS WITH A RELATIVELY ZONAL FLOW TO FOLLOW AND A LESS
IMPRESSIVE RIPPLE IN THE FLOW LATE FRI. THIS SHORTWAVE WILL
TRANSLATE DOWN THROUGH THE LOWER LEVELS WITH TROUGH MOVING THROUGH
THURS AFTN. EXPECT MOST SHWR/TSTM ACTIVITY TO OCCUR MORE TOWARD
THE BEGINNING OF THE PERIOD AS SHORTWAVE TRAVERSES THE AREA AND
SHOULD TAPER OFF BY THURS EVENING FROM WEST TO EAST. ONCE
SHORTWAVE AND ASSOCIATED LOWER LEVEL TROUGH PASSES ON THURS GFS
SHOWS A NICE DRY PUNCH MOVING IN AS WINDS THROUGH THE LOWER TO MID
LEVELS SHIFT AROUND TO THE W-NW AND WILL MAINTAIN A WESTERLY
COMPONENT THROUGH THE REMAINDER OF THE PERIOD. BY FRI ANY SHOWER
ACTIVITY WILL BE FOCUSED ALONG SEA BREEZE IN THE AFTN AS IT PUSHES
INLAND. THURS WILL DEFINITELY BE THE MORE ACTIVE DAY WITH GFS/NAM
AND SREF SHOWING BEST CHC OF PCP AROUND 12 TO 18Z. MU CAPE WILL BE
UP TO AROUND 2500 J/KG AND PCP WATER VALUES MAXING OUT AROUND 1.7
INCHES THURS MORNING. THE ONE PIECE THAT WILL BE LACKING IS THE
TIMING DOES NOT COINCIDE WITH MAX HEATING.
AS FOR TEMPERATURES THURS WILL REMAIN AROUND CLIMO WITH CLOUDS AND
PCP HOLDING IT DOWN A BIT. FRI AFTN TEMPS SHOULD SOAR THROUGH THE
80S WITH SUNSHINE AND FEWER SHWRS EXPECTED AS WELL AS A MORE
WESTERLY FLOW THROUGH THE LOWER LEVELS OF THE ATMOSPHERE. TEMPS AT
NIGHT WILL REMAIN ABOVE NORMAL IN THE MID 60S MOST PLACES.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 3 PM WEDNESDAY...SLIGHT PATTERN SHIFT AS FLAT UPPER RIDGE IS
SUPPRESSED TO THE SOUTH AFTER THE WEEKEND. ONE MORE WARM DAY ON
SATURDAY WITH TEMPS NEAR 90 AWAY FROM THE IMMEDIATE COAST...BUT THE
FRONT AND UPPER DISTURBANCES WILL BE CLOSE ENOUGH TO WARRANT SLIGHT
CHANCE POPS. FRONT MOVES THROUGH SAT NIGHT AND SUNDAY...BUT COULD
REMAIN UNSETTLED INTO MONDAY DEPENDING ON THE VALIDITY OF UPPER
DISTURBANCES ADVERTISED BY GFS. WILL HOLD LOW CHANCE POPS IN FOR
MONDAY. DRIER HIGH PRESSURE RIDGING INTO THE CAROLINAS FROM THE
NORTH WILL KEEP TEMPS NEAR OR SLIGHTLY BELOW SEASONAL NORMALS
TUE-WED.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
A STATIONARY FRONT IS LOCATED SOUTHWEST TO NORTHEAST ACROSS CENTRAL
NC. A WEAK PRESSURE TROUGH IS LOCATED FROM FLO-LBT. TERMINALS ARE
CURRENTLY VFR WITH TEMPO MVFR CEILINGS OCCURRING. THIS SHOULD BE THE
CASE THROUGH 21Z. WINDS THIS AFTERNOON WILL BE SOUTH TO SOUTHWEST AT
10-20 KNOTS WITH POSSIBLY HIGHER GUSTS AT TIMES.
THE BEST CHANCE FOR ORGANIZED THUNDERSTORM DEVELOPMENT WILL BE ALONG
THE STATIONARY FRONT TO THE NORTH OF THE TERMINALS THIS AFTERNOON.
FORECAST STEERING FLOW/FRONTAL POSITIONS SUGGESTS THIS ACTIVITY
WILL STAY WELL NORTH AND NORTHWEST OF THE FLO/LBT TERMINALS THROUGH
THE AFTERNOON. SHOWERS ALONG THE SEA BREEZE SHOULD DISSIPATE THROUGH
21Z AS BEST PVA...OMEGA AND LOW LEVEL MOISTURE THROUGH H8 SHIFTS
NORTH. BY MID-EVENING THE GFS IS SUGGESTING SOME OF THE CONVECTION
TO THE NORTHWEST OF THE TERMINALS WILL ADVECT INTO THE FLO/LBT
TERMINALS. HAVE ADDED A TEMPO GROUP FOR THUNDERSTORMS ROUGHLY
04Z-08Z. OTHER SHOWERS ARE FORECAST TO DEVELOP AT THE COASTAL
TERMINALS AFTER MIDNIGHT. LOOK FOR MVFR CEILINGS TO DEVELOP AT
FLO/LBT BY 10Z WITH MVFR CEILINGS DEVELOPING AT THE COASTAL
TERMINALS BY 12Z. THERE SHOULD BE A GOOD CHANCE OF SHOWERS/ISOLATED
CB`S THURSDAY MORNING.
EXTENDED OUTLOOK THROUGH SUNDAY...SCATTERED THUNDERSTORMS THURSDAY
AND SUNDAY. ISOLATED THUNDERSTORMS FRIDAY AND SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM WEDNESDAY...AS SW LOW LEVEL JET INCREASES TONIGHT...
EXPECT WINDS WILL PICK UP ACROSS THE WATERS AS ENVIRONMENT BECOMES
INCREASINGLY WELL MIXED. PRESSURE GRADIENT WILL TIGHTEN UP ACROSS
THE WATERS...ESPECIALLY AFTER MIDNIGHT. SE SWELL...PERIODS OF 9/10
SEC WILL PERSIST THIS PERIOD...CONTRIBUTING TO WAVE HEIGHTS. THAT
BEING SAID...MARGINAL SMALL CRAFT CONDITIONS ARE EXPECTED TO
MATERIALIZE AFTER MIDNIGHT ACROSS THE WATERS FROM LITTLE RIVER INLET
TO SURF CITY AND TO PERSIST INTO THU NIGHT. FURTHER S...WILL KEEP
CONDITIONS JUST BELOW ADVISORY CRITERIA. SMALL CRAFT SHOULD EXERCISE
CAUTION WILL BE HEADLINED FROM LITTLE RIVER INLET TO THE SOUTH
SANTEE RIVER...BEGINNING AFTER MIDNIGHT.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...SOUTHERLY WINDS EXPECTED THROUGH MOST OF
THE PERIOD. WILL START OUT WITH A GOOD 15 TO 20 KTS ON THURS WHICH
WILL PUSH SEAS INTO SCA CRITERIA FOR THE NORTHERN 2 ZONES. SCA
WILL BASICALLY RUN UP THROUGH MIDNIGHT THURS INTO FRI. OTHERWISE
SEAS WILL REMAIN IN THE 3 TO 5 FT RANGE MOST WATERS. WINDS TAKE ON
A MORE WESTERLY COMPONENT FOR A SHORT TIME LATE THURS AFTER
SHORTWAVE MOVES THROUGH.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 PM WEDNESDAY...MODEST SW FLOW WILL CARRY THROUGH SATURDAY
INTO SAT NIGHT...WITH SPEEDS 15-20 KT AHEAD OF THE APPROACHING
FRONT. FULLY DEVELOPED SEAS AT THAT POINT WILL BE KNOCKING ON THE
DOOR OF SCA...BUT FOR NOW WILL KEEP 3-5 FT IN THE OFFICIAL FORECAST.
FRONT DROPS THROUGH ON SUNDAY MORNING...WITH A WIND SHIFT TO THE
NORTH. NOT MUCH OF A SURGE BEHIND THE FRONT GIVEN WEAK CAA AND THE
RELUCTANCE OF THE HIGH PRESSURE TO BUILD IN. WIND SPEEDS WILL BE
10-15 KT THROUGH MONDAY...WITH SEAS SUBSIDING TO AROUND 2 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 AM THURSDAY TO 2 AM EDT FRIDAY FOR
AMZ250-252.
&&
$$
SYNOPSIS...RGZ
NEAR TERM...RJD
SHORT TERM...RGZ
LONG TERM...RAS
AVIATION...MRR
000
FXUS62 KMHX 061752
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
153 PM EDT WED MAY 6 2009
.SYNOPSIS...
HIGH PRESSURE OVER AREA TONIGHT THROUGH SATURDAY. FRONT TO MOVE
THROUGH NC SATURDAY NIGHT. HIGH PRESSURE WILL BUILD BACK IN SUNDAY
NIGHT.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
WL BE INTERESTING TO SEE WHAT HAPPENS OVR NGT TNGT. SHWRS CONT TO MV
NE THRU CWA ALNG THE CSTL PLAINS AREAS. VIS SAT PIX SHOWG PSBL CBRZ
FORMATION THIS AFTN. THIS MAY HELP SPPRS ACTVTY OVR ONSLOW AND
CARTERET CNTYS. ALL MDLS SHOWG A LULL IN ACTVTY THIS EVE AS UPR LVLS
LACKG MUCH ENERGY. NXT PIECE OF ENERGY WL SWING THRU LT TNGT WI AN
INCRS IN POPS STRTG ARND 7Z.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
UNSTTLD WX WL CONT THRU THE RMNDR OF THE WK AS UPR TROF SLOWLY
APPRCHS FRM THE W. MDLS SHOWG UPR TROF MVS THRU AREA THU NGT. LWR
MSTR AND LACK OF UPR LVL ENERGY ON FRI SHUD HELP KP THE DAY DRY.
ANTHR S/WV MVS THRU THE FLO FRI NGT. DOESNT APPR TO HV TOO MUCH MSTR
WI THIS. ANTHR SYS APPCHS IN THE FAST FLO APPRCHS SAT WI A WK UPR
LVL S/WV SO WL HV LO POPS SAT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
FRNT TO MV THRU AREA SAT NGT WI LO LVL FLO BCMG NLY. ANTHR SURGE
APPRS TO DROP THRU AND DISSIPATE SUNDAY NGT. STL RMNG IN ZNL FLO
ALFT WI WK S/WVS ZIPPG THRU THE FLO. THIS WL KP A CHC OF SHWRS OVR
CWA THRU FIRST PART OF THE WK. UPR RDG TO BLD IN ON TUE WI SFC RDG
BLDG DWN FRM THE N.
&&
.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
MVFR CEILINGS WILL RISE TO VFR BY 17Z. EXPECTING CONVECTION TO
INCREASE IN BOTH COVERAGE AND INTENSITY THIS AFTERNOON/EARLY
EVENING WITH TORRENTIAL RAINS...GUSTY WINDS AND HAIL THE MAIN
THREATS TO AVIATION. ANY STORM WILL PRODUCE LIFR/IFR CONDITIONS.
LATER TONIGHT AN APPROACHING SHORTWAVE COULD BRING WIDESPREAD
SHOWERS AND THUNDERSTORMS TO THE AREA WHICH COULD PERSIST INTO
EARLY THURSDAY AFTERNOON.
MOIST SLY FLOW WITH A FRONTAL BOUNDARY IN THE VICINITY WILL
CONTINUE TO BRING THE THREAT OF SHOWERS AND THUNDERSTORMS THROUGH
THE REMAINDER OF THE WEEK.
&&
.MARINE...
NO CHANGES TO HEADLINES WITH DETERIORATING CONDITIONS EXPECTED
BEGINNING THIS AFTERNOON AS SW FLOW PICKS UP TO AROUND 20 KT THIS
AFTERNOON THEN 25 KT THIS EVENING. SEAS WILL BE BUILDING WITH
CONDITIONS REMAINING ROUGH THROUGH AT LEAST THURSDAY NIGHT.
PREVIOUS DISCUSSION: SOUTHERLY FLOW CONTINUES ACROSS THE WATERS
WITH THE BERMUDA HIGH ACROSS THE WRN ATLANTIC AND STALLED FRONT
ACROSS CENTRAL NC. WINDS GENERALLY 15 KT OR LESS WITH SEAS MAINLY
3 TO 5 FT...HOWEVER THE CENTRAL WATERS REPORTING UP TO 6 FT AND
WILL CONTINUE THE SCA ACROSS THE CENTRAL WATERS TODAY. AN AREA OF
LOW PRES WILL LIFT NE ACROSS THE APPALACHIANS LATER TODAY AND
TONIGHT AND WILL BRING TIGHTER GRADIENTS ACROSS THE WATERS
BRINGING INCREASED WINDS AND SEAS. WAVEWATCH LOOKS ON TRACK AND
FOLLOWED CLOSELY THROUGH THE FORECAST. EXPECTING SEAS UP TO 6 FT
TO MOVE INTO THE OUTER PORTIONS OF THE WATERS S OF OCRACOKE INLET
AND N OF OREGON INLET LATE THIS AFTERNOON AS SLY FLOW INCREASES
AND HAVE SCA STARTING AT 4 PM FOR THOSE ZONES. WINDS EXPECTED TO
INCREASE TO AROUND 25 KT ACROSS MOST OF THE WATERS AFTER MIDNIGHT
TONIGHT AND CONTINUE THROUGH THU MORNING AND HAVE SCA IN THE
SOUNDS FOR THIS PERIOD. GRADIENTS RELAX A BIT LATE THU WITH WINDS
DROPPING BELOW SCA CONDITIONS HOWEVER WAVEWATCH CONTINUES TO BRING
SEAS UP TO 6-7 FT ACROSS THE CENTRAL AND SOUTHERN WATERS THROUGH
THE REST OF THE WEEK WITH A LONG AND PERSISTENT SOUTHERLY FETCH
INTO THE REGION. THE PATTERN LOOKS TO FINALLY BREAK DOWN LATE THIS
WEEKEND WITH A FRONT PUSHING THROUGH THE WATERS AND HIGH PRES
BUILDING IN FROM THE NW.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM TO 2 PM EDT THURSDAY FOR AMZ130-
135.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT SUNDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 2 PM EDT
SUNDAY FOR AMZ156-158.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 4 PM EDT
THURSDAY FOR AMZ150.
&&
$$
SYNOPSIS...CGG
NEAR TERM...CGG
SHORT TERM...CGG
LONG TERM...CGG
AVIATION...JME/SK
MARINE...JME/SK
000
FXUS62 KILM 061734
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
135 PM EDT WED MAY 6 2009
.SYNOPSIS...
SEVERAL IMPULSES WILL TRAVERSE THE AREA INTO THE WEEKEND BRINGING A
RISK OF SHOWERS AND THUNDERSTORMS EACH DAY. A COLD FRONT WILL MOVE
ACROSS THE AREA SATURDAY NIGHT AND SUNDAY MORNING BRINGING DRIER AIR
FOR THE EARLY PART OF NEXT WEEK AS HIGH PRESSURE BUILDS INTO THE
REGION FROM THE NORTH.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM WEDNESDAY...A PIECE OF SHORTWAVE ENERGY WILL MOVE
ACROSS THE SOUTHERN APPALACHIANS THIS MORNING AND ACROSS THE
FORECAST AREA THIS AFTERNOON. A STRONGER SHORT WAVE WILL MOVE BY TO
OUR N AND W TONIGHT WITH FORECAST AREA ON SOUTHERN FRINGES OF THIS
FEATURE. THIS SUGGESTS TWO DISTINCT BOUTS OF SHOWERS AND
THUNDERSTORMS OR AT LEAST AFTERNOON AND EVE CONVECTION BEING
REINFORCED BY LATE NIGHT AND OVERNIGHT CONVECTION. AFTER COMPLETING
THE ENVIRONMENTAL CHECKLIST...CAPES AND HELICITIES WILL BE HIGHEST
FROM THE PEE DEE REGION AND POINTS TO THE SW THIS AFTERNOON AND
SEVERE WEATHER RISK MAY BE HIGHEST HERE. CLOUD COVER IS AGAIN A
CONCERN TODAY...BUT LACK OF ONGOING CONVECTION SHOULD ALLOW THE
CLOUDS TO THIN INTO THE AFTERNOON HOURS. WET BULB ZEROS AROUND 11
KFT THIS AFTERNOON SHOULD LIMIT NUMBER OF LARGE HAIL REPORTS.
FRONTAL BOUNDARY TO OUR N WILL CONTINUE TO SHIFT N THROUGH THE
PERIOD WITH APPROACH OF WAVE OF LOW PRESSURE E KY/TN. COUPLE THIS
WITH HIGH LCLS AND RISK OF TORNADOES SEEMS REMOTE...BUT NOT ZERO
GIVEN THERE IS SOME VEERING OF WIND WITH HEIGHT IN LOWEST 3 KM.
STRONG TO DAMAGING WIND APPEARS TO BE GREATEST RISK IN STRONGEST
CELLS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...FLAT 5H PATTERN WILL LIMIT SOUTHWARD ADVANCE
OF FRONT STALLED NORTH AND WEST OF THE AREA. WEAK SHORTWAVE TROF
CROSSING THE AREA AT THE START OF THE PERIOD MAY BE ABLE TO GET SOME
PRECIP GOING...BUT THIS WILL BE DEPENDANT ON LOCATION AND STRENGTH
OF PVA...SOMETHING THE GUIDANCE HAS BEEN HAVING A LOT OF TROUBLE
WITH LATELY. LATEST GFS MOVES A SECOND SHORTWAVE OUT OF THE EASTERN
GULF COAST REGION INTO THE AREA LATER THU. THE 00Z NAM/CANADIAN AND
12Z ECMWF DO NOT HAVE THIS FEATURE AND IT APPEARS TO BE FEEDBACK.
APPEARS THE ONLY MECHANISM FOR STORM DEVELOPMENT THU AFTERNOON WILL
BE SEA BREEZE AND DIURNAL INSTABILITY.
FORECAST SOUNDINGS SHOW MID LEVEL DRY AIR MOVING IN FROM THE WEST
THU NIGHT INTO FRI. DRY AIR REMAINS OVER THE AREA THROUGH THE END OF
THE PERIOD AND...COMBINED WITH LACK OF DYNAMICS...WILL KEEP PRECIP
CHANCES LOW. WENT WITH SLIGHT CHANCE POPS AS SEA BREEZE AND WEAK
PIEDMONT TROF WILL LIKELY BE THE BEST SOURCES OF CONVECTION.
TEMPERATURES WILL CONTINUE TO RUN NEAR OR SLIGHTLY ABOVE CLIMO
DURING THE DAY AND 5 TO 10 DEGREES ABOVE CLIMO BY NIGHT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 3 AM WEDNESDAY...UPPER PATTERN REMAINS RELATIVELY FLAT
THROUGH THE PERIOD WITH GUIDANCE HINTING AT 5H RIDGE STARTING TO
DEVELOP LATE IN THE PERIOD. IT SHOULD BE NOTED THAT BOTH THE
GFS/ECMWF WERE DOING THIS EARLIER IN THE WEEK ONLY TO BACK OFF A
FEW DAYS LATER. FLATTER UPPER PATTERN WILL KEEP WEATHER ACROSS THE
AREA UNSETTLED AS STALLED SURFACE BOUNDARY REMAINS IN THE AREA
AND SHORTWAVE TROF PASS FROM TIME TO TIME. TIMING THE WAVES AT
LONGER TIME PERIOD IS DIFFICULT AT BEST. SURFACE BOUNDARY DOES
EVENTUALLY PUSH SOUTH OF THE AREA...BUT STILL NOT A LOT OF
AGREEMENT ON WHEN. BEST GUESS IS SUN BUT COULD END UP BEING ON
MON. ONCE THE BOUNDARY IS SOUTH OF THE AREA IT WILL STALL BEFORE
TRYING TO RETURN NORTH AS A WARM FRONT BY THE END OF THE PERIOD.
TEMPERATURES PRE FRONT WILL REMAIN NEAR TO ABOVE CLIMO WITH NEAR
TO SLIGHTLY BELOW CLIMO TEMPS POST FRONT.
&&
.AVIATION /18Z WEDNESDAY THROUGH SUNDAY/...
A STATIONARY FRONT IS LOCATED SOUTHWEST TO NORTHEAST ACROSS CENTRAL
NC. A WEAK PRESSURE TROUGH IS LOCATED FROM FLO-LBT. TERMINALS ARE
CURRENTLY VFR WITH TEMPO MVFR CEILINGS OCCURRING. THIS SHOULD BE THE
CASE THROUGH 21Z. WINDS THIS AFTERNOON WILL BE SOUTH TO SOUTHWEST AT
10-20 KNOTS WITH POSSIBLY HIGHER GUSTS AT TIMES.
THE BEST CHANCE FOR ORGANIZED THUNDERSTORM DEVELOPMENT WILL BE ALONG
THE STATIONARY FRONT TO THE NORTH OF THE TERMINALS THIS AFTERNOON.
FORECAST STEERING FLOW/FRONTAL POSITIONS SUGGESTS THIS ACTIVITY
WILL STAY WELL NORTH AND NORTHWEST OF THE FLO/LBT TERMINALS THROUGH
THE AFTERNOON. SHOWERS ALONG THE SEA BREEZE SHOULD DISSIPATE THROUGH
21Z AS BEST PVA...OMEGA AND LOW LEVEL MOISTURE THROUGH H8 SHIFTS
NORTH. BY MID-EVENING THE GFS IS SUGGESTING SOME OF THE CONVECTION
TO THE NORTHWEST OF THE TERMINALS WILL ADVECT INTO THE FLO/LBT
TERMINALS. HAVE ADDED A TEMPO GROUP FOR THUNDERSTORMS ROUGHLY
04Z-08Z. OTHER SHOWERS ARE FORECAST TO DEVELOP AT THE COASTAL
TERMINALS AFTER MIDNIGHT. LOOK FOR MVFR CEILINGS TO DEVELOP AT
FLO/LBT BY 10Z WITH MVFR CEILINGS DEVELOPING AT THE COASTAL
TERMINALS BY 12Z. THERE SHOULD BE A GOOD CHANCE OF SHOWERS/ISOLATED
CB`S THURSDAY MORNING.
EXTENDED OUTLOOK THROUGH SUNDAY...SCATTERED THUNDERSTORMS THURSDAY
AND SUNDAY. ISOLATED THUNDERSTORMS FRIDAY AND SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM WEDNESDAY...SIMILAR TO YESTERDAY...S WINDS WILL BE
CAPPED AT 20 KT OR LESS THIS PERIOD. SE SWELL...PERIODS EVERY 10
SECONDS...AND WIND COMPONENT WILL CONTRIBUTE TO SEA HEIGHTS IN 3 TO
5 FT RANGE.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...SOUTHERLY FLOW WILL CONTINUE THROUGH THE
PERIOD WITH SURFACE HIGH CENTERED EAST OF THE WATERS. GFS WIND
SPEEDS HAVE BEEN OVERDONE FOR THE PAST SEVERAL DAYS AND EXPECT THIS
TREND TO CONTINUE AS LONG AS SOUTHERLY FLOW REMAINS OVER THE WATERS.
PROLONGED PERIOD OF SOUTHERLY FETCH...BETWEEN 10 AND 15 KT FOR MOST
OF THE PERIOD...WILL STEADILY BUILD SEAS. IT IS POSSIBLE THAT SCA
WILL BE NEEDED WITHIN THE FORECAST PERIOD...BUT NOT LIKELY. SEAS
EXPECTED TO REMAIN IN THE 3 TO 5 FT RANGE.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 AM WEDNESDAY...SOUTHERLY FLOW CONTINUES OVER THE WATERS
SAT INTO SUN BUT FRONT DROPPING IN FROM THE NORTH MAY ALLOW
SURFACE HIGH TO THE WEST TO BUILD OVER THE WATERS LATE
SUN...RESULTING IN NORTH TO NORTHWEST FLOW DEVELOPING. CONFIDENCE
IN TIMING OF FRONTAL PASSAGE IS LOW AND SOUTHERLY FLOW COULD END
UP DOMINATING THE LONG TERM PERIOD. GRADIENT BECOMES PINCHED AHEAD
OF FRONT AND SPEEDS MAY INCREASE TO NEAR 20 KT LATER SAT. SEAS WILL
CONTINUE TO RUN 3 TO 5 FT BUT HEADLINE REQUIRING SEAS COULD EASILY
DEVELOP LATER SAT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RJD
SHORT TERM...III
LONG TERM...III
AVIATION...MRR
000
FXUS62 KRAH 061636
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1236 PM EDT WED MAY 6 2009
.SYNOPSIS...
A STATIONARY FRONT OVER CENTRAL NC WILL GRADUALLY WEAKEN AND
DISSIPATE TODAY. AN UPPER LEVEL TROUGH AND ATTENDANT SURFACE TROUGH
WILL PUSH EAST ACROSS CENTRAL NC LATE TONIGHT THROUGH THURSDAY
MORNING.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 AM WEDNESDAY...
BREAKS HAVE DEVELOPED IN STRATUS DECK OVER THE SANDHILLS...COASTAL
PLAIN AND EASTERN PIEDMONT. THIS HAS CAUSED TEMPS TO SHOOT WELL IN
TO THE 70S. CLOUDS THICKER OVER THE NW PIEDMONT (PER GSO SOUNDING).
WATER VAPOR IMAGERY DEPICTS POSSIBLE MCV ENTERING SW NC...TRIGGERING
A BAND OF SHOWERS AND ISOLATED THUNDERSTORMS IN THE SOUTHERN AND
CENTRAL MOUNTAINS.
A FEW HOURS OF HEATING SHOULD RESULT IN A MODERATELY UNSTABLE AIR
MASS ALONG AND SOUTH OF OLD SURFACE BOUNDARY THAT STRETCHES FROM
SCOTLAND NECK-RALEIGH TO LEXINGTON. NEAR TERM MODELS HAVE THIS
BOUNDARY BECOMING LESS DEFINITIVE THIS AFTERNOON.
HOWEVER...CONSIDERING DEWPOINT CONTRAST ON EITHER SIDE OF SURFACE
FRONT...BELIEVE THAT FRONT WILL REMAIN A PLAYER THIS AFTERNOON. WITH
APPROACH OF MCV THIS AFTERNOON AND PRIMED AIR MASS OVER AT LEAST THE
SOUTHERN HALF OF CWA...EXPECT SCATTERED THUNDERSTORMS TO DEVELOP
BETWEEN 17Z-20Z. BEST ORGANIZED STORMS WILL BE OVER THE SOUTHERN AND
WESTERN PIEDMONT...POSSIBLY WORKING INTO THE SANDHILLS AND SOUTHERN
COASTAL PLAIN. 12Z UPPER AIR ANALYSIS DEPICTS GOOD MID/UPPER LEVEL
DIVERGENCE IMMEDIATELY W-SW OF OUR REGION WITH NOSE OF 850MB AND
700MB AIMED AT OUR SW COUNTIES. APPEARS TO BE POTENTIAL FOR ANOTHER
ROUND OF SEVERE STORMS THIS AFTERNOON ESPECIALLY ALONG AND SOUTH OF
HIGHWAY 64. MAIN THREAT APPEARS TO BE DAMAGING WIND GUSTS AND LARGE
HAIL AS WELL AS ISOLATED TORNADOES AS 0-3KM BULK SHEAR INCREASES TO
40-50KTS AFTER 18Z (PER 06S GFS AND 12Z NAM).
MAIN ADJUSTMENTS TO FORECAST WAS TO INCREASE POPS TO THE LOW END OF
LIKELY OVER THE SOUTH AND WEST SECTIONS. MAX TEMPS APPEAR TO BE ON
TARGET. WHILE TRIAD REGION IN THE 50S AT LATE MORNING...POTENTIAL
FOR TEMPS TO WARM RAPIDLY BY MID/LATE AFTERNOON AS MODEL DEPICT
FRONT DISSIPATING AND SLY FLOW RETURN TO THIS AREA. IF FRONT HOLDS
FIRM...THEN MAX TEMPS WILL HOLD IN THE MID 60S.
POTENTIAL FOR ANOTHER ROUND OF SEVERE STORMS LATE THIS EVENING
OVERNIGHT AS NEXT UPPER LEVEL WAVE APPROACHES FROM THE WEST AND
CROSS REGION BETWEEN 06-12Z THU. THIS FEATURE MAY INITIATE A BAND OF
CONVECTION OVER THE MOUNTAINS WITH POTENTIAL FOR A ROTATING STORM OR
TWO POSSIBLE. AT THIS TIME...THE SEVERE WEATHER THREAT APPEARS TO BE
GREATEST WEST AND NW OF RALEIGH INCLUDING THE TRIAD REGION. WILL
ASSESS THIS RISK NEXT FEW HOURS AS NEW DATA ARRIVES.
FOR THE REST OF TODAY AND TONIGHT...ANOTHER ROUND OF STORMS...OR
EVEN PERHAPS TWO...ARE EXPECTED THIS AFTERNOON AND OVERNIGHT AS THE
SFC BOUNDARY IS FORECAST TO WEAKEN AND LIFT NORTH THIS AFTERNOON IN
RESPONSE TO AN APPROACHING UPPER LEVEL TROUGH AND ATTENDANT SURFACE
TROUGH FROM THE WEST. MODELS HAVE TRENDED SLOWER AND SLIGHTLY
STRONGER WITH THE PASSAGE OF THE DIGGING UPPER WAVE...WITH IT NOW
FORECAST TO REMAIN WEST OF THE MTNS THROUGH 06Z THURSDAY...SWINGING
EAST ACROSS CENTRAL NC BETWEEN 12 TO 18Z.
THE FIRST ROUND OF CONVECTION LOOKS TO DEVELOP THIS
AFTERNOON...PRIMARILY DRIVEN BY DIFFERENTIAL HEATING AS THE BOUNDARY
WEAKENS AND LIFTS NORTH ACROSS THE AREA...WITH NO DISCERNIBLE
UPPER LEVEL SUPPORT...AS COMPARED TO PAST COUPLE OF DAYS. DEEP LAYER
SHEAR OF 30 TO 40 KTS WITH SBCAPE OF 800 TO 1200 JOULES FROM US 1
SOUTH AND EAST WILL SUPPORT A SLIGHT RISK OF SEVERE STORMS WITH THE
MAJOR THREAT BEING STRONG DAMAGING WINDS AND HAIL AS LARGE NICKEL TO
QUARTER SIZE HAIL AS WET-BULB ZEROS ARE FORECAST TO REMAIN PRETTY
HIGH...AOA 11.5KFT. A MUCH SMALLER...ISOLATED TORNADO THREAT COULD
EXIST AS WELL...IF THE FRONT MANAGES TO LINGER OR HOLD ON LONGER AS
THE NAM SUGGESTS...BETWEEN 18 TO 21Z (THE GFS LIFTS THE FRONT TO THE
NORTH FASTER THAN THE NAM). BUT THE GREATEST SEVERE THREAT AND HIGHER
POPS WILL ARRIVE IN THE EVENING AND OVERNIGHT HOURS WITH THE DIGGING
UPPER WAVE...WITH STRONG JET SUPPORT...BOTH ALOFT AND IN THE
LOW-LEVELS...ACCOMPANYING THE UPPER WAVE AS IT TRAVERSES WEST TO TO
EAST ACROSS THE REGION. CONCEPTUAL RECOGNITION WOULD SUGGEST A
LINEAR SQUALL LINE MOVING THROUGH THE AREA BETWEEN MIDNIGHT THROUGH
DAYBREAK THURSDAY MORNING...WITH VERTICAL SHEAR INCREASING TO 45 TO
50 KTS WITH MORE THAN ADEQUATE INSTABILITY AS MODELS SHOW 800 TO
1000 J/KG OF MUCAPE WITH 700 TO 500MB MID-LEVEL LAPSE RATES OF 7 TO
7.25 ACROSS THE AREA. ADDITIONALLY...ALTHOUGH THE FLOW IS MAINLY
UNIDIRECTIONAL...0 TO 1 KM HELICITY OF 250 TO 300 MS-1 MOVES THROUGH
THE AREA LATE WEDNESDAY NIGHT/THURSDAY MORNING AS SURFACE TROUGH
AND LOW-LEVEL JET MOVES THROUGH THE AREA. IF A SECONDARY MESO-LOW
DEVELOPS ALONG THE TROUGH...AN ISOLATED TORNADO COULD ACCOMPANY THE
THREAT OF STRAIGHT LINE WINDS AND HAIL.
TOUGH TEMPERATURE FORECAST FOR TODAY...DEPENDENT ON THE TIMING
OF THE DISSIPATION OF THE MORNING STRATUS...BUT SHOULD SEE A
SHARP TEMPERATURE GRADIENT ACROSS CENTRAL NC. WILL LEAN TOWARD THE
WARMER MAV GUIDANCE WITH BOUNDARY WEAKENING...AND THUS ALLOWING FOR
THE POTENTIAL TO SEE MORE BREAKS IN CLOUD COVER. HIGHS IN THE LOWER
TO MID 70S NW TO LOWER TO MID 80S SOUTHEAST. LOWS TONIGHT IN THE IN
THE MID TO UPPER 60S.
&&
.SHORT TERM /THURSDAY/...
AS OF 315 AM WEDNESDAY...
THE SLOWER TIMING OF THE PASSAGE OF THE UPPER TROUGH THURSDAY WILL
RESULT IN SCATTERED SHOWERS AND THUNDER EXTENDING WELL INTO THE
AFTERNOON...MAINLY ACROSS THE CENTRAL PIEDMONT AND COASTAL PLAIN
WITH SURFACE TROUGH AND 850-700 THETA-E RIDGE EXTENDING OVER THE
COASTAL PLAIN REGION. STRONG SURFACE HEATING WILL RESULT IN MARGINAL
TO MODEST INSTABILITY OF 1000 TO 1500 JOULES WITH COOLING
TEMPERATURES ALOFT BRINGING AN INCREASE THREAT OF HAIL AS WET-BULB
ZEROES FALL TO AROUND 9KFT ACROSS THE NORTHERN HALF. HIGHS AROUND 80
IN THE NW TO MID 80S SE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
AS OF 340 AM TUESDAY...
ANY REMAINING CONVECTION FROM THURSDAY AFTERNOON SHOULD QUICKLY
DIMINISH DURING THE EVENING WITH THE ONSET OF NOCTURNAL COOLING AND
THE DEPARTURE OF THE MID LEVEL SHORTWAVE. WHILE THE AIRMASS WILL
REMAIN MOIST AND SLIGHTLY UNSTABLE OVERNIGHT...DO NOT SEE ANY
FORCING MECHANISMS AT THIS TIME TO SUPPORT CARRYING POPS PAST THE
EARLY EVENING. IT WILL BE A HUMID AND VERY MILD NIGHT WITH LOWS IN
THE LOW TO MID 60S. PATCHY FOG WILL CERTAINLY BE POSSIBLE GIVEN
DEWPOINTS IN THE 60S AND SOUTHWESTERLY WINDS BECOMING RATHER LIGHT.
THE STATIONARY BOUNDARY OVER THE LOWER MS VALLEY WILL CONTINUE TO
GENERATE WIDESPREAD CONVECTION ACROSS THAT REGION...EXTENDING EAST
INTO THE TN VALLEY ON FRIDAY. IT IS POSSIBLE THAT THIS CONVECTION
COULD GENERATE A MCV THAT THEN TRANSLATES EAST TOWARD OUR REGION
UNDER ZONAL FLOW ALOFT. THE NAM INDICATES THIS IS A POSSIBILITY...
BUT THE GFS AND ECMWF ARE LESS ENTHUSIASTIC. CANNOT HANG OUR HAT ON
THESE POTENTIAL MCVS THIS FAR OUT. SO WITH NO REAL IDENTIFIABLE
TRIGGERS...WE ARE LEFT WITH THE POTENTIAL FOR DIURNALLY DRIVEN
CONVECTION SUPPORTED BY PRECIPITABLE WATERS OVER 1.5 INCHES AND
MLCAPES BETWEEN 1000-2000 J/KG. LOW LEVEL THICKNESSES AND 850 MB
TEMPS SUPPORT HIGHS IN THE 85-88 DEGREE RANGE. WILL KEEP A SLIGHT
CHANCE OF CONVECTION IN THE FORECAST FRIDAY NIGHT GIVEN THE
POTENTIAL FOR A MINOR PERTURBATION TO MOVE THROUGH...INTERACTING
WITH A VERY MOIST AND LINGERING INSTABILITY. LOWS FRI NIGHT 63-67.
A COLD FRONT WILL BEGIN TO APPROACH FROM THE NORTHWEST BY LATE
SATURDAY AFTERNOON AS THE MID LEVEL TROUGH OVER THE GREAT LAKES
BEGINS TO MOVE EAST TOWARD NEW ENGLAND. EXPECT SCATTERED SHOWERS AND
THUNDERSTORMS TO DEVELOP ALONG AND AHEAD OF THE FRONT AS IT
ENCOUNTERS AN UNSTABLE AIRMASS REPRESENTED WITH MLCAPES ABOVE 1000
J/KG. THE BEST MID LEVEL FORCING STAYS WELL TO OUR NORTH...SO WILL
KEEP POPS IN THE CHANCE CATEGORY. THICKNESSES SOAR INTO THE
1410-1415M RANGE...SUPPORTING AT LEAST UPPER 80S FOR HIGHS. WOULD
NOT BE SURPRISED TO SEE SOME LOW 90S IN THE SOUTH AND EAST.
THE FRONT MOVES THROUGH SATURDAY NIGHT WITH A CONTINUED CHANCE FOR
SCATTERED CONVECTION...BUT AS INSTABILITY WANES OVERNIGHT...CHANCES
WILL GRADUALLY DIMINISH. HIGH PRESSURE BEGINS TO BUILD IN FROM THE
NORTH ON SUNDAY...BRINGING A RETURN TO SEASONABLE TEMPS. MODEL
GUIDANCE ALL OVER THE PLACE ON HOW FAR SOUTH THE FRONT MAKES IT AND
ANY POTENTIAL OVERRUNNING PRECIP OVER CENTRAL NC. WILL KEEP THE
FORECAST DRY FOR NOW AND AWAIT A BETTER CONSENSUS.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 1158 AM WEDNESDAY...
AREA OF LIFR/IFR CEILINGS AND VISIBILITY NORTH OF A STALLED SURFACE
BOUNDARY WILL SLOWLY LIFT/IMPROVE AS INSOLATION HEATS AIRMASS.
ELSEWHERE...MVFR/VFR CEILINGS EXPECTED THROUGH 02Z WITH BASES
VARYING BETWEEN 2500-4000FT. AFTERNOON HEATING WILL INITIALLY
TRIGGER SCATTERED SHOWERS AND STORMS...MAINLY OVER THE SOUTHERN AND
EASTERN COUNTIES WHERE HEATING HAS BEEN OCCURRING SINCE 10 AM.
SHOWERS AND STORMS EXPECTED TO BECOME MORE NUMEROUS AFTER 21Z. MAY
SEE CONVECTION WANE A BIT BY 00Z BUT EXPECTED TO REINVIGORATE AFTER
03Z AS SIGNIFICANT UPPER LEVEL DISTURBANCE CROSSES NEAR OUR AREA.
CLOUD BASES EXPECTED TO VARY WIDELY ACROSS REGION AFTER 00Z WITH
BASES AT OR ABOVE 3000FT IN THE SE AROUND KFAY AND KRWI TO NEAR OR
BELOW 1000FT AT KINT AND KGSO.
SCATTERED SHOWERS AND THUNDERSTORMS MAY BE ONGOING ACROSS THE REGION
THURSDAY MORNING. CONVECTION EXPECTED DIMINISH BY LATE MORNING BUT
REDEVELOPMENT OVER THE SANDHILLS AND COASTAL PLAIN AS AIRMASS
BECOMES UNSTABLE DUE TO HEATING.
TRANQUIL WEATHER EXPECTED THURSDAY NIGHT AND FRIDAY MORNING WITH
POCKETS OF MVFR FOG ANTICIPATED.
UNSETTLED WEATHER EXPECTED FRIDAY NIGHT THROUGH MONDAY AS A COLD
FRONT APPROACHES THEN STALLS IN OUR VICINITY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...WSS
SHORT TERM...CBL
LONG TERM...JFB
AVIATION...WSS
000
FXUS62 KMHX 061615
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
1215 PM EDT WED MAY 6 2009
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN NORTHWEST OF THE AREA THROUGH THE
END OF THE WEEK. SEVERAL AREAS OF LOW PRESSURE WILL LIFT NORTHEAST
ALONG THE FRONT INTO THIS WEEKEND. HIGH PRESSURE BUILDS IN FROM
THE NORTHWEST LATE IN THE WEEKEND AND EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1215 PM...ISOLATED SHWRS OVR CWA...MAINLY INLAND AREAS ATTM.
BNDRY WELL N OF AREA WITH SW FLO CONTG. AMS CONTS MST AND MARGINALLY
UNSTBL...HWVR FCST SNDGS NOT AS MST AS YSTRDY...XPCT LESS CVRG THAN
YSTRDY. LUKG AT PW/S ABV 1.5 SO AM CUD SEE SUM HVY DWNPOURS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
A STRONGER MID LVL TROF CURRENTLY OVR THE SOUTHERN PLAINS WILL BE
APPROACHING THE FCST AREA LATE TNGT. SHUD SEE WANING CONVECTION
WITH DIURNAL HEAT LOSS DURING THE EVENING THEN RENEWED CONVECTION
LATE TNGT INTO EARLY THU ASSOCD WITH THE MID LVL FORCING. THIS
DEPICTED FAIRLY WELL IN NAM/ECMWF MODELS WITH THE OPERATIONAL
GFS...WHICH INITIALIZE POORLY TO BEGIN WITH...AN UNRELIABLE
OUTLIER. THIS CONVECTIVE ACTIVITY LOOKS TO BE COMING THRU DURING
THE DIURNALLY UNFAVORABLE TIME OF DAY BUT CANT RULE OUT
ADDITIONAL SVR WEATHER THREAT LATER TNGT INTO EARLY THU GIVEN THE
STRONG MID/UPPER LVL SUPPORT. MAY SEE BULK OF PCPN MOVING OFF THE
COAST BY ARND MIDDAY THURS WITH SUBSIDENCE/DRYING IN THE WAKE OF
THE MID LVL TROF LEADING TO LOWER PCPN CHCS DURING THE AFTN.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
A PERIOD OF LESSER PCPN CHCS/COVERAGE APPEARS TO BE DEVELOPING
EARLY THIS FCST PERIOD AS THE LINGERING FRONT TO NW MOVES FARTHER
NORTH AND MID LVL FLOW BECOMES MORE ZONAL. HARD TO COMPLETELY
RULE OUT POPS GIVEN THE CONTINUED HIGH DEW POINTS AND POTENTIAL
FOR ANY WEAK MID LVL DISTURBANCE TO SET OFF CONVECTION ALONG
RESIDUAL MESOSCALE BNDYS. SHUD SEE MORE SUN ON FRI WHICH WILL HELP
BOOST TEMPS WELL INTO 80S AND POSSBLY NEAR 90 INLAND. MID LVL
ENERGY DROPPING SE THRU THE MIDWEST WILL PROPEL THE LINGERING SFC
BNDRY ACRS THE MID ATLC REGION DURING THE FIRST HALF OF THE
WEEKEND WITH RENEWED INCREASED CHCS FOR PCPN ON SATURDAY. THE
FRONT MAY SLOW DOWN AND STALL NEAR OR SOUTH OF THE AREA DURING THE
SECOND HALF OF THE WEEKEND SO WILL CONTINUE LOW PCPN CHCS INTO
SUNDAY. IT LOOKS AS IF THE FRONT WILL FINALLY PUSH WELL SOUTH OF
THE AREA AS ADDITIONAL NORTHERN STREAM ENERGY LOADS THE MID LVL
TROF OFF THE EASTERN SEABOARD. WITH SFC HIGH PRES BUILDING IN FROM
THE NORTH MAY FINALLY SEE AN END TO THE RECENT WET/UNSETTLED
WEATHER PERIOD EARLY NEXT WEEK.
&&
.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
MVFR CEILINGS WILL RISE TO VFR BY 17Z. EXPECTING CONVECTION TO
INCREASE IN BOTH COVERAGE AND INTENSITY THIS AFTERNOON/EARLY
EVENING WITH TORRENTIAL RAINS...GUSTY WINDS AND HAIL THE MAIN
THREATS TO AVIATION. ANY STORM WILL PRODUCE LIFR/IFR CONDITIONS.
LATER TONIGHT AN APPROACHING SHORTWAVE COULD BRING WIDESPREAD
SHOWERS AND THUNDERSTORMS TO THE AREA WHICH COULD PERSIST INTO
EARLY THURSDAY AFTERNOON.
MOIST SLY FLOW WITH A FRONTAL BOUNDARY IN THE VICINITY WILL
CONTINUE TO BRING THE THREAT OF SHOWERS AND THUNDERSTORMS THROUGH
THE REMAINDER OF THE WEEK.
&&
.MARINE...
NO CHANGES TO HEADLINES WITH DETERIORATING CONDITIONS EXPECTED
BEGINNING THIS AFTERNOON AS SW FLOW PICKS UP TO AROUND 20 KT THIS
AFTERNOON THEN 25 KT THIS EVENING. SEAS WILL BE BUILDING WITH
CONDITIONS REMAINING ROUGH THROUGH AT LEAST THURSDAY NIGHT.
PREVIOUS DISCUSSION: SOUTHERLY FLOW CONTINUES ACROSS THE WATERS
WITH THE BERMUDA HIGH ACROSS THE WRN ATLANTIC AND STALLED FRONT
ACROSS CENTRAL NC. WINDS GENERALLY 15 KT OR LESS WITH SEAS MAINLY
3 TO 5 FT...HOWEVER THE CENTRAL WATERS REPORTING UP TO 6 FT AND
WILL CONTINUE THE SCA ACROSS THE CENTRAL WATERS TODAY. AN AREA OF
LOW PRES WILL LIFT NE ACROSS THE APPALACHIANS LATER TODAY AND
TONIGHT AND WILL BRING TIGHTER GRADIENTS ACROSS THE WATERS
BRINGING INCREASED WINDS AND SEAS. WAVEWATCH LOOKS ON TRACK AND
FOLLOWED CLOSELY THROUGH THE FORECAST. EXPECTING SEAS UP TO 6 FT
TO MOVE INTO THE OUTER PORTIONS OF THE WATERS S OF OCRACOKE INLET
AND N OF OREGON INLET LATE THIS AFTERNOON AS SLY FLOW INCREASES
AND HAVE SCA STARTING AT 4 PM FOR THOSE ZONES. WINDS EXPECTED TO
INCREASE TO AROUND 25 KT ACROSS MOST OF THE WATERS AFTER MIDNIGHT
TONIGHT AND CONTINUE THROUGH THU MORNING AND HAVE SCA IN THE
SOUNDS FOR THIS PERIOD. GRADIENTS RELAX A BIT LATE THU WITH WINDS
DROPPING BELOW SCA CONDITIONS HOWEVER WAVEWATCH CONTINUES TO BRING
SEAS UP TO 6-7 FT ACROSS THE CENTRAL AND SOUTHERN WATERS THROUGH
THE REST OF THE WEEK WITH A LONG AND PERSISTENT SOUTHERLY FETCH
INTO THE REGION. THE PATTERN LOOKS TO FINALLY BREAK DOWN LATE THIS
WEEKEND WITH A FRONT PUSHING THROUGH THE WATERS AND HIGH PRES
BUILDING IN FROM THE NW.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM TO 2 PM EDT THURSDAY FOR AMZ130-
135.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT SUNDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 2 PM EDT
SUNDAY FOR AMZ156-158.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 4 PM EDT
THURSDAY FOR AMZ150.
&&
$$
SYNOPSIS...BTC
NEAR TERM...CGG
SHORT TERM...BTC
LONG TERM...BTC
AVIATION...JME/SK
MARINE...JME/SK
000
FXUS62 KMHX 061548
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
1148 AM EDT WED MAY 6 2009
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN NORTHWEST OF THE AREA THROUGH THE
END OF THE WEEK. SEVERAL AREAS OF LOW PRESSURE WILL LIFT NORTHEAST
ALONG THE FRONT INTO THIS WEEKEND. HIGH PRESSURE BUILDS IN FROM
THE NORTHWEST LATE IN THE WEEKEND AND EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ALTHO A MOIST AND MARGINALLY UNSTABLE AIRMASS STILL IN PLACE
OVER EASTERN NC TODAY...EXPECTING OVERALL LESS PCPN/CONVECTIVE
COVERAGE THAN YESTERDAY. FRONTAL BNDRY HAS STALLED JUST TO NW OF
FCST AREA THIS MORNING AND WILL BE SLOWLY RETREATING BACK NORTH AS
A WEAK UPR IMPULSE LIFTS NE ACRS THE MID ATLC REGION TODAY. NOT
EXPECTING MUCH PCPN THIS MORN WITH LTL TO TRIGGER CONVECTION BUT
SHUD PICK UP IN COVERAGE AND INTENSITY WITH DIURNAL HEATING AND
PASSING OF SHORT WAVE TO NW. BEST PCPN CHCS WILL RESIDE ACRS FAR
NW COUNTIES IN VCNTY OF RETREATING FRONT WITH REDUCED CHCS TO SE
WHERE FORCING WILL BE WEAKER. THERE IS STILL A THREAT FOR SEVERE
WEATHER TODAY...AGAIN WITH BEST CHCS OVR NW AREAS WHERE STABILITY
AND VERTICAL SHEAR WILL BE MAXIMIZED. HEAVY PCPN ALSO LIKELY IN
THE STRONGER STORMS WITH PRECIP WATERS ARND 1.5 INCHES WHICH CUD
LEAD TO LOCALIZED FLOODING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
A STRONGER MID LVL TROF CURRENTLY OVR THE SOUTHERN PLAINS WILL BE
APPROACHING THE FCST AREA LATE TNGT. SHUD SEE WANING CONVECTION
WITH DIURNAL HEAT LOSS DURING THE EVENING THEN RENEWED CONVECTION
LATE TNGT INTO EARLY THU ASSOCD WITH THE MID LVL FORCING. THIS
DEPICTED FAIRLY WELL IN NAM/ECMWF MODELS WITH THE OPERATIONAL
GFS...WHICH INITIALIZE POORLY TO BEGIN WITH...AN UNRELIABLE
OUTLIER. THIS CONVECTIVE ACTIVITY LOOKS TO BE COMING THRU DURING
THE DIURNALLY UNFAVORABLE TIME OF DAY BUT CANT RULE OUT
ADDITIONAL SVR WEATHER THREAT LATER TNGT INTO EARLY THU GIVEN THE
STRONG MID/UPPER LVL SUPPORT. MAY SEE BULK OF PCPN MOVING OFF THE
COAST BY ARND MIDDAY THURS WITH SUBSIDENCE/DRYING IN THE WAKE OF
THE MID LVL TROF LEADING TO LOWER PCPN CHCS DURING THE AFTN.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
A PERIOD OF LESSER PCPN CHCS/COVERAGE APPEARS TO BE DEVELOPING
EARLY THIS FCST PERIOD AS THE LINGERING FRONT TO NW MOVES FARTHER
NORTH AND MID LVL FLOW BECOMES MORE ZONAL. HARD TO COMPLETELY
RULE OUT POPS GIVEN THE CONTINUED HIGH DEW POINTS AND POTENTIAL
FOR ANY WEAK MID LVL DISTURBANCE TO SET OFF CONVECTION ALONG
RESIDUAL MESOSCALE BNDYS. SHUD SEE MORE SUN ON FRI WHICH WILL HELP
BOOST TEMPS WELL INTO 80S AND POSSBLY NEAR 90 INLAND. MID LVL
ENERGY DROPPING SE THRU THE MIDWEST WILL PROPEL THE LINGERING SFC
BNDRY ACRS THE MID ATLC REGION DURING THE FIRST HALF OF THE
WEEKEND WITH RENEWED INCREASED CHCS FOR PCPN ON SATURDAY. THE
FRONT MAY SLOW DOWN AND STALL NEAR OR SOUTH OF THE AREA DURING THE
SECOND HALF OF THE WEEKEND SO WILL CONTINUE LOW PCPN CHCS INTO
SUNDAY. IT LOOKS AS IF THE FRONT WILL FINALLY PUSH WELL SOUTH OF
THE AREA AS ADDITIONAL NORTHERN STREAM ENERGY LOADS THE MID LVL
TROF OFF THE EASTERN SEABOARD. WITH SFC HIGH PRES BUILDING IN FROM
THE NORTH MAY FINALLY SEE AN END TO THE RECENT WET/UNSETTLED
WEATHER PERIOD EARLY NEXT WEEK.
&&
.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
MVFR CEILINGS WILL RISE TO VFR BY 17Z. EXPECTING CONVECTION TO
INCREASE IN BOTH COVERAGE AND INTENSITY THIS AFTERNOON/EARLY
EVENING WITH TORRENTIAL RAINS...GUSTY WINDS AND HAIL THE MAIN
THREATS TO AVIATION. ANY STORM WILL PRODUCE LIFR/IFR CONDITIONS.
LATER TONIGHT AN APPROACHING SHORTWAVE COULD BRING WIDESPREAD
SHOWERS AND THUNDERSTORMS TO THE AREA WHICH COULD PERSIST INTO
EARLY THURSDAY AFTERNOON.
MOIST SLY FLOW WITH A FRONTAL BOUNDARY IN THE VICINITY WILL
CONTINUE TO BRING THE THREAT OF SHOWERS AND THUNDERSTORMS THROUGH
THE REMAINDER OF THE WEEK.
&&
.MARINE...
NO CHANGES TO HEADLINES WITH DETERIORATING CONDITIONS EXPECTED
BEGINNING THIS AFTERNOON AS SW FLOW PICKS UP TO AROUND 20 KT THIS
AFTERNOON THEN 25 KT THIS EVENING. SEAS WILL BE BUILDING WITH
CONDITIONS REMAINING ROUGH THROUGH AT LEAST THURSDAY NIGHT.
PREVIOUS DISCUSSION: SOUTHERLY FLOW CONTINUES ACROSS THE WATERS
WITH THE BERMUDA HIGH ACROSS THE WRN ATLANTIC AND STALLED FRONT
ACROSS CENTRAL NC. WINDS GENERALLY 15 KT OR LESS WITH SEAS MAINLY
3 TO 5 FT...HOWEVER THE CENTRAL WATERS REPORTING UP TO 6 FT AND
WILL CONTINUE THE SCA ACROSS THE CENTRAL WATERS TODAY. AN AREA OF
LOW PRES WILL LIFT NE ACROSS THE APPALACHIANS LATER TODAY AND
TONIGHT AND WILL BRING TIGHTER GRADIENTS ACROSS THE WATERS
BRINGING INCREASED WINDS AND SEAS. WAVEWATCH LOOKS ON TRACK AND
FOLLOWED CLOSELY THROUGH THE FORECAST. EXPECTING SEAS UP TO 6 FT
TO MOVE INTO THE OUTER PORTIONS OF THE WATERS S OF OCRACOKE INLET
AND N OF OREGON INLET LATE THIS AFTERNOON AS SLY FLOW INCREASES
AND HAVE SCA STARTING AT 4 PM FOR THOSE ZONES. WINDS EXPECTED TO
INCREASE TO AROUND 25 KT ACROSS MOST OF THE WATERS AFTER MIDNIGHT
TONIGHT AND CONTINUE THROUGH THU MORNING AND HAVE SCA IN THE
SOUNDS FOR THIS PERIOD. GRADIENTS RELAX A BIT LATE THU WITH WINDS
DROPPING BELOW SCA CONDITIONS HOWEVER WAVEWATCH CONTINUES TO BRING
SEAS UP TO 6-7 FT ACROSS THE CENTRAL AND SOUTHERN WATERS THROUGH
THE REST OF THE WEEK WITH A LONG AND PERSISTENT SOUTHERLY FETCH
INTO THE REGION. THE PATTERN LOOKS TO FINALLY BREAK DOWN LATE THIS
WEEKEND WITH A FRONT PUSHING THROUGH THE WATERS AND HIGH PRES
BUILDING IN FROM THE NW.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM TO 2 PM EDT THURSDAY FOR AMZ130-
135.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT SUNDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 2 PM EDT
SUNDAY FOR AMZ156-158.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 4 PM EDT
THURSDAY FOR AMZ150.
&&
$$
SYNOPSIS...BTC
NEAR TERM...BTC
SHORT TERM...BTC
LONG TERM...BTC
AVIATION...JME/SK
MARINE...JME/SK
000
FXUS62 KRAH 061510
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1109 AM EDT WED MAY 6 2009
.SYNOPSIS...
A STATIONARY FRONT OVER CENTRAL NC WILL GRADUALLY WEAKEN AND
DISSIPATE TODAY. AN UPPER LEVEL TROUGH AND ATTENDANT SURFACE TROUGH
WILL PUSH EAST ACROSS CENTRAL NC LATE TONIGHT THROUGH THURSDAY
MORNING...BRINING ANOTHER ROUND OF SHOWERS AND STORMS TO CENTRAL
NORTH CAROLINA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 AM WEDNESDAY...
BREAKS HAVE DEVELOPED IN STRATUS DECK OVER THE SANDHILLS...COASTAL
PLAIN AND EASTERN PIEDMONT. THIS HAS CAUSED TEMPS TO SHOOT WELL IN
TO THE 70S. CLOUDS THICKER OVER THE NW PIEDMONT (PER GSO SOUNDING).
WATER VAPOR IMAGERY DEPICTS POSSIBLE MCV ENTERING SW NC...TRIGGERING
A BAND OF SHOWERS AND ISOLATED THUNDERSTORMS IN THE SOUTHERN AND
CENTRAL MOUNTAINS.
A FEW HOURS OF HEATING SHOULD RESULT IN A MODERATELY UNSTABLE AIR
MASS ALONG AND SOUTH OF OLD SURFACE BOUNDARY THAT STRETCHES FROM
SCOTLAND NECK-RALEIGH TO LEXINGTON. NEAR TERM MODELS HAVE THIS
BOUNDARY BECOMING LESS DEFINITIVE THIS AFTERNOON.
HOWEVER...CONSIDERING DEWPOINT CONTRAST ON EITHER SIDE OF SURFACE
FRONT...BELIEVE THAT FRONT WILL REMAIN A PLAYER THIS AFTERNOON. WITH
APPROACH OF MCV THIS AFTERNOON AND PRIMED AIR MASS OVER AT LEAST THE
SOUTHERN HALF OF CWA...EXPECT SCATTERED THUNDERSTORMS TO DEVELOP
BETWEEN 17Z-20Z. BEST ORGANIZED STORMS WILL BE OVER THE SOUTHERN AND
WESTERN PIEDMONT...POSSIBLY WORKING INTO THE SANDHILLS AND SOUTHERN
COASTAL PLAIN. 12Z UPPER AIR ANALYSIS DEPICTS GOOD MID/UPPER LEVEL
DIVERGENCE IMMEDIATELY W-SW OF OUR REGION WITH NOSE OF 850MB AND
700MB AIMED AT OUR SW COUNTIES. APPEARS TO BE POTENTIAL FOR ANOTHER
ROUND OF SEVERE STORMS THIS AFTERNOON ESPECIALLY ALONG AND SOUTH OF
HIGHWAY 64. MAIN THREAT APPEARS TO BE DAMAGING WIND GUSTS AND LARGE
HAIL AS WELL AS ISOLATED TORNADOES AS 0-3KM BULK SHEAR INCREASES TO
40-50KTS AFTER 18Z (PER 06S GFS AND 12Z NAM).
MAIN ADJUSTMENTS TO FORECAST WAS TO INCREASE POPS TO THE LOW END OF
LIKELY OVER THE SOUTH AND WEST SECTIONS. MAX TEMPS APPEAR TO BE ON
TARGET. WHILE TRIAD REGION IN THE 50S AT LATE MORNING...POTENTIAL
FOR TEMPS TO WARM RAPIDLY BY MID/LATE AFTERNOON AS MODEL DEPICT
FRONT DISSIPATING AND SLY FLOW RETURN TO THIS AREA. IF FRONT HOLDS
FIRM...THEN MAX TEMPS WILL HOLD IN THE MID 60S.
POTENTIAL FOR ANOTHER ROUND OF SEVERE STORMS LATE THIS EVENING
OVERNIGHT AS NEXT UPPER LEVEL WAVE APPROACHES FROM THE WEST AND
CROSS REGION BETWEEN 06-12Z THU. THIS FEATURE MAY INITIATE A BAND OF
CONVECTION OVER THE MOUNTAINS WITH POTENTIAL FOR A ROTATING STORM OR
TWO POSSIBLE. AT THIS TIME...THE SEVERE WEATHER THREAT APPEARS TO BE
GREATEST WEST AND NW OF RALEIGH INCLUDING THE TRIAD REGION. WILL
ASSESS THIS RISK NEXT FEW HOURS AS NEW DATA ARRIVES.
FOR THE REST OF TODAY AND TONIGHT...ANOTHER ROUND OF STORMS...OR
EVEN PERHAPS TWO...ARE EXPECTED THIS AFTERNOON AND OVERNIGHT AS THE
SFC BOUNDARY IS FORECAST TO WEAKEN AND LIFT NORTH THIS AFTERNOON IN
RESPONSE TO AN APPROACHING UPPER LEVEL TROUGH AND ATTENDANT SURFACE
TROUGH FROM THE WEST. MODELS HAVE TRENDED SLOWER AND SLIGHTLY
STRONGER WITH THE PASSAGE OF THE DIGGING UPPER WAVE...WITH IT NOW
FORECAST TO REMAIN WEST OF THE MTNS THROUGH 06Z THURSDAY...SWINGING
EAST ACROSS CENTRAL NC BETWEEN 12 TO 18Z.
THE FIRST ROUND OF CONVECTION LOOKS TO DEVELOP THIS
AFTERNOON...PRIMARILY DRIVEN BY DIFFERENTIAL HEATING AS THE BOUNDARY
WEAKENS AND LIFTS NORTH ACROSS THE AREA...WITH NO DISCERNIBLE
UPPER LEVEL SUPPORT...AS COMPARED TO PAST COUPLE OF DAYS. DEEP LAYER
SHEAR OF 30 TO 40 KTS WITH SBCAPE OF 800 TO 1200 JOULES FROM US 1
SOUTH AND EAST WILL SUPPORT A SLIGHT RISK OF SEVERE STORMS WITH THE
MAJOR THREAT BEING STRONG DAMAGING WINDS AND HAIL AS LARGE NICKEL TO
QUARTER SIZE HAIL AS WET-BULB ZEROS ARE FORECAST TO REMAIN PRETTY
HIGH...AOA 11.5KFT. A MUCH SMALLER...ISOLATED TORNADO THREAT COULD
EXIST AS WELL...IF THE FRONT MANAGES TO LINGER OR HOLD ON LONGER AS
THE NAM SUGGESTS...BETWEEN 18 TO 21Z (THE GFS LIFTS THE FRONT TO THE
NORTH FASTER THAN THE NAM). BUT THE GREATEST SEVERE THREAT AND HIGHER
POPS WILL ARRIVE IN THE EVENING AND OVERNIGHT HOURS WITH THE DIGGING
UPPER WAVE...WITH STRONG JET SUPPORT...BOTH ALOFT AND IN THE
LOW-LEVELS...ACCOMPANYING THE UPPER WAVE AS IT TRAVERSES WEST TO TO
EAST ACROSS THE REGION. CONCEPTUAL RECOGNITION WOULD SUGGEST A
LINEAR SQUALL LINE MOVING THROUGH THE AREA BETWEEN MIDNIGHT THROUGH
DAYBREAK THURSDAY MORNING...WITH VERTICAL SHEAR INCREASING TO 45 TO
50 KTS WITH MORE THAN ADEQUATE INSTABILITY AS MODELS SHOW 800 TO
1000 J/KG OF MUCAPE WITH 700 TO 500MB MID-LEVEL LAPSE RATES OF 7 TO
7.25 ACROSS THE AREA. ADDITIONALLY...ALTHOUGH THE FLOW IS MAINLY
UNIDIRECTIONAL...0 TO 1 KM HELICITY OF 250 TO 300 MS-1 MOVES THROUGH
THE AREA LATE WEDNESDAY NIGHT/THURSDAY MORNING AS SURFACE TROUGH
AND LOW-LEVEL JET MOVES THROUGH THE AREA. IF A SECONDARY MESO-LOW
DEVELOPS ALONG THE TROUGH...AN ISOLATED TORNADO COULD ACCOMPANY THE
THREAT OF STRAIGHT LINE WINDS AND HAIL.
TOUGH TEMPERATURE FORECAST FOR TODAY...DEPENDENT ON THE TIMING
OF THE DISSIPATION OF THE MORNING STRATUS...BUT SHOULD SEE A
SHARP TEMPERATURE GRADIENT ACROSS CENTRAL NC. WILL LEAN TOWARD THE
WARMER MAV GUIDANCE WITH BOUNDARY WEAKENING...AND THUS ALLOWING FOR
THE POTENTIAL TO SEE MORE BREAKS IN CLOUD COVER. HIGHS IN THE LOWER
TO MID 70S NW TO LOWER TO MID 80S SOUTHEAST. LOWS TONIGHT IN THE IN
THE MID TO UPPER 60S.
&&
.SHORT TERM /THURSDAY/...
AS OF 315 AM WEDNESDAY...
THE SLOWER TIMING OF THE PASSAGE OF THE UPPER TROUGH THURSDAY WILL
RESULT IN SCATTERED SHOWERS AND THUNDER EXTENDING WELL INTO THE
AFTERNOON...MAINLY ACROSS THE CENTRAL PIEDMONT AND COASTAL PLAIN
WITH SURFACE TROUGH AND 850-700 THETA-E RIDGE EXTENDING OVER THE
COASTAL PLAIN REGION. STRONG SURFACE HEATING WILL RESULT IN MARGINAL
TO MODEST INSTABILITY OF 1000 TO 1500 JOULES WITH COOLING
TEMPERATURES ALOFT BRINGING AN INCREASE THREAT OF HAIL AS WET-BULB
ZEROES FALL TO AROUND 9KFT ACROSS THE NORTHERN HALF. HIGHS AROUND 80
IN THE NW TO MID 80S SE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
AS OF 340 AM TUESDAY...
ANY REMAINING CONVECTION FROM THURSDAY AFTERNOON SHOULD QUICKLY
DIMINISH DURING THE EVENING WITH THE ONSET OF NOCTURNAL COOLING AND
THE DEPARTURE OF THE MID LEVEL SHORTWAVE. WHILE THE AIRMASS WILL
REMAIN MOIST AND SLIGHTLY UNSTABLE OVERNIGHT...DO NOT SEE ANY
FORCING MECHANISMS AT THIS TIME TO SUPPORT CARRYING POPS PAST THE
EARLY EVENING. IT WILL BE A HUMID AND VERY MILD NIGHT WITH LOWS IN
THE LOW TO MID 60S. PATCHY FOG WILL CERTAINLY BE POSSIBLE GIVEN
DEWPOINTS IN THE 60S AND SOUTHWESTERLY WINDS BECOMING RATHER LIGHT.
THE STATIONARY BOUNDARY OVER THE LOWER MS VALLEY WILL CONTINUE TO
GENERATE WIDESPREAD CONVECTION ACROSS THAT REGION...EXTENDING EAST
INTO THE TN VALLEY ON FRIDAY. IT IS POSSIBLE THAT THIS CONVECTION
COULD GENERATE A MCV THAT THEN TRANSLATES EAST TOWARD OUR REGION
UNDER ZONAL FLOW ALOFT. THE NAM INDICATES THIS IS A POSSIBILITY...
BUT THE GFS AND ECMWF ARE LESS ENTHUSIASTIC. CANNOT HANG OUR HAT ON
THESE POTENTIAL MCVS THIS FAR OUT. SO WITH NO REAL IDENTIFIABLE
TRIGGERS...WE ARE LEFT WITH THE POTENTIAL FOR DIURNALLY DRIVEN
CONVECTION SUPPORTED BY PRECIPITABLE WATERS OVER 1.5 INCHES AND
MLCAPES BETWEEN 1000-2000 J/KG. LOW LEVEL THICKNESSES AND 850 MB
TEMPS SUPPORT HIGHS IN THE 85-88 DEGREE RANGE. WILL KEEP A SLIGHT
CHANCE OF CONVECTION IN THE FORECAST FRIDAY NIGHT GIVEN THE
POTENTIAL FOR A MINOR PERTURBATION TO MOVE THROUGH...INTERACTING
WITH A VERY MOIST AND LINGERING INSTABILITY. LOWS FRI NIGHT 63-67.
A COLD FRONT WILL BEGIN TO APPROACH FROM THE NORTHWEST BY LATE
SATURDAY AFTERNOON AS THE MID LEVEL TROUGH OVER THE GREAT LAKES
BEGINS TO MOVE EAST TOWARD NEW ENGLAND. EXPECT SCATTERED SHOWERS AND
THUNDERSTORMS TO DEVELOP ALONG AND AHEAD OF THE FRONT AS IT
ENCOUNTERS AN UNSTABLE AIRMASS REPRESENTED WITH MLCAPES ABOVE 1000
J/KG. THE BEST MID LEVEL FORCING STAYS WELL TO OUR NORTH...SO WILL
KEEP POPS IN THE CHANCE CATEGORY. THICKNESSES SOAR INTO THE
1410-1415M RANGE...SUPPORTING AT LEAST UPPER 80S FOR HIGHS. WOULD
NOT BE SURPRISED TO SEE SOME LOW 90S IN THE SOUTH AND EAST.
THE FRONT MOVES THROUGH SATURDAY NIGHT WITH A CONTINUED CHANCE FOR
SCATTERED CONVECTION...BUT AS INSTABILITY WANES OVERNIGHT...CHANCES
WILL GRADUALLY DIMINISH. HIGH PRESSURE BEGINS TO BUILD IN FROM THE
NORTH ON SUNDAY...BRINGING A RETURN TO SEASONABLE TEMPS. MODEL
GUIDANCE ALL OVER THE PLACE ON HOW FAR SOUTH THE FRONT MAKES IT AND
ANY POTENTIAL OVERRUNNING PRECIP OVER CENTRAL NC. WILL KEEP THE
FORECAST DRY FOR NOW AND AWAIT A BETTER CONSENSUS.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 730 AM WEDNESDAY...
A NEARLY SATURATED AIRMASS REMAINS IN PLACE OVER CENTRAL NC AS A
STALLED FRONT OVER CENTRAL NC IS EXPECTED TO GRADUALLY WEAKEN TODAY
AS IT LIFTS NORTH OF THE AREA. THE WIDESPREAD LIFR CEILINGS ALONG
AND NORTH OF THE FRONT...AND THE MVFR CEILINGS SOUTH OF THE FRONT
WILL BE SLOW TO LIFT...WITH THE LATEST SREF SHOWING IFR CEILINGS
LINGERING THROUGH 15Z TO 16Z IN THE VICINITY OF THE DISSIPATING
FRONTAL ZONE ACROSS THE NORTHERN AND CENTRAL PIEDMONT. BY 18 TO 21Z
CEILINGS ACROSS SOUTHERN PORTIONS SHOULD IMPROVE TO VFR...WITH MVFR
ACROSS THE FAR NORTH. DIFFERENTIAL AFTERNOON HEATING COMBINED WITH
POSSIBLE MCS OUTFLOW WILL SUPPORT SCATTERED SHOWERS AND
THUNDERSTORMS WITH CONVECTION EXPECTED TO PERSIST WELL INTO THE
NIGHT AS AN UPPER LEVEL DISTURBANCE AND SURFACE TROUGH CROSSES THE
REGION FROM WEST TO EAST OVERNIGHT. THUS EXPECT SIGNIFICANT AVIATION
IMPACTS OF IFR TO MVFR CEILINGS TO CONTINUE THROUGH 12Z THURSDAY.
SHOWERS COULD LINGER INTO THE AFTERNOON ACROSS EASTERN NC AS SURFACE
TROUGH LINGERS ACROSS THE REGION. UNSETTLED WEATHER AND PERIODS OF
ADVERSE AVIATION CONDITIONS COULD RETURN AS EARLY AS
SATURDAY...PERSISTING INTO THE WEEKEND AS ANOTHER FRONT APPROACHES
FROM THE WEST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...WSS
SHORT TERM...CBL
LONG TERM...JFB
AVIATION...CBL
000
FXUS62 KILM 061442
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1040 AM EDT WED MAY 6 2009
.SYNOPSIS...
A STATIONARY FRONT EXTENDING FROM WEST TO EAST ACROSS CENTRAL NORTH
CAROLINA WILL HELP DEVELOP SHOWERS AND THUNDERSTORMS DURING THE NEXT
FEW DAYS AS WAVES OF LOW PRESSURE DEVELOP AND RIDE ALONG THIS
BOUNDARY. DRIER AIR WILL MAKE ITS WAY INTO THE REGION SATURDAY OR
SUNDAY AS HIGH PRESSURE STARTS TO BUILD INTO THE REGION FROM THE
WEST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM WEDNESDAY...A PIECE OF SHORTWAVE ENERGY WILL MOVE
ACROSS THE SOUTHERN APPALACHIANS THIS MORNING AND ACROSS THE
FORECAST AREA THIS AFTERNOON. A STRONGER SHORT WAVE WILL MOVE BY TO
OUR N AND W TONIGHT WITH FORECAST AREA ON SOUTHERN FRINGES OF THIS
FEATURE. THIS SUGGESTS TWO DISTINCT BOUTS OF SHOWERS AND
THUNDERSTORMS OR AT LEAST AFTERNOON AND EVE CONVECTION BEING
REINFORCED BY LATE NIGHT AND OVERNIGHT CONVECTION. AFTER COMPLETING
THE ENVIRONMENTAL CHECKLIST...CAPES AND HELICITIES WILL BE HIGHEST
FROM THE PEE DEE REGION AND POINTS TO THE SW THIS AFTERNOON AND
SEVERE WEATHER RISK MAY BE HIGHEST HERE. CLOUD COVER IS AGAIN A
CONCERN TODAY...BUT LACK OF ONGOING CONVECTION SHOULD ALLOW THE
CLOUDS TO THIN INTO THE AFTERNOON HOURS. WET BULB ZEROS AROUND 11
KFT THIS AFTERNOON SHOULD LIMIT NUMBER OF LARGE HAIL REPORTS.
FRONTAL BOUNDARY TO OUR N WILL CONTINUE TO SHIFT N THROUGH THE
PERIOD WITH APPROACH OF WAVE OF LOW PRESSURE E KY/TN. COUPLE THIS
WITH HIGH LCLS AND RISK OF TORNADOES SEEMS REMOTE...BUT NOT ZERO
GIVEN THERE IS SOME VEERING OF WIND WITH HEIGHT IN LOWEST 3 KM.
STRONG TO DAMAGING WIND APPEARS TO BE GREATEST RISK IN STRONGEST
CELLS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...FLAT 5H PATTERN WILL LIMIT SOUTHWARD ADVANCE
OF FRONT STALLED NORTH AND WEST OF THE AREA. WEAK SHORTWAVE TROF
CROSSING THE AREA AT THE START OF THE PERIOD MAY BE ABLE TO GET SOME
PRECIP GOING...BUT THIS WILL BE DEPENDANT ON LOCATION AND STRENGTH
OF PVA...SOMETHING THE GUIDANCE HAS BEEN HAVING A LOT OF TROUBLE
WITH LATELY. LATEST GFS MOVES A SECOND SHORTWAVE OUT OF THE EASTERN
GULF COAST REGION INTO THE AREA LATER THU. THE 00Z NAM/CANADIAN AND
12Z ECMWF DO NOT HAVE THIS FEATURE AND IT APPEARS TO BE FEEDBACK.
APPEARS THE ONLY MECHANISM FOR STORM DEVELOPMENT THU AFTERNOON WILL
BE SEA BREEZE AND DIURNAL INSTABILITY.
FORECAST SOUNDINGS SHOW MID LEVEL DRY AIR MOVING IN FROM THE WEST
THU NIGHT INTO FRI. DRY AIR REMAINS OVER THE AREA THROUGH THE END OF
THE PERIOD AND...COMBINED WITH LACK OF DYNAMICS...WILL KEEP PRECIP
CHANCES LOW. WENT WITH SLIGHT CHANCE POPS AS SEA BREEZE AND WEAK
PIEDMONT TROF WILL LIKELY BE THE BEST SOURCES OF CONVECTION.
TEMPERATURES WILL CONTINUE TO RUN NEAR OR SLIGHTLY ABOVE CLIMO
DURING THE DAY AND 5 TO 10 DEGREES ABOVE CLIMO BY NIGHT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 3 AM WEDNESDAY...UPPER PATTERN REMAINS RELATIVELY FLAT
THROUGH THE PERIOD WITH GUIDANCE HINTING AT 5H RIDGE STARTING TO
DEVELOP LATE IN THE PERIOD. IT SHOULD BE NOTED THAT BOTH THE
GFS/ECMWF WERE DOING THIS EARLIER IN THE WEEK ONLY TO BACK OFF A
FEW DAYS LATER. FLATTER UPPER PATTERN WILL KEEP WEATHER ACROSS THE
AREA UNSETTLED AS STALLED SURFACE BOUNDARY REMAINS IN THE AREA
AND SHORTWAVE TROF PASS FROM TIME TO TIME. TIMING THE WAVES AT
LONGER TIME PERIOD IS DIFFICULT AT BEST. SURFACE BOUNDARY DOES
EVENTUALLY PUSH SOUTH OF THE AREA...BUT STILL NOT A LOT OF
AGREEMENT ON WHEN. BEST GUESS IS SUN BUT COULD END UP BEING ON
MON. ONCE THE BOUNDARY IS SOUTH OF THE AREA IT WILL STALL BEFORE
TRYING TO RETURN NORTH AS A WARM FRONT BY THE END OF THE PERIOD.
TEMPERATURES PRE FRONT WILL REMAIN NEAR TO ABOVE CLIMO WITH NEAR
TO SLIGHTLY BELOW CLIMO TEMPS POST FRONT.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
A STATIONARY FRONT IS LOCATED SOUTHWEST TO NORTHEAST ACROSS CENTRAL
NC. A WEAK PRESSURE TROUGH IS LOCATED FROM FLO-LBT. TERMINALS ARE
CURRENTLY VFR WITH TEMPO MVFR CEILINGS OCCURRING. THIS SHOULD BE THE
CASE THROUGH 15-16Z. WINDS TODAY WILL BECOME SOUTH TO SOUTHWEST AT
10-20 KNOTS WITH POSSIBLY HIGHER GUSTS AT TIMES.
THE BEST AREA FOR THUNDERSTORM DEVELOPMENT WILL BE ALONG THE
STATIONARY FRONT TO THE NORTH OF THE TERMINALS. FORECAST STEERING
FLOW/FRONTAL POSITIONS SUGGESTS THIS ACTIVITY WILL STAY WELL NORTH
AND NORTHWEST OF THE FLO/LBT TERMINALS THROUGH THE AFTERNOON. BEST
OMEGAS/LOW LEVEL MOISTURE THROUGH 85H/PVA WILL BE NEAR ILM...AND
FROM FLO-LBT THROUGH 18Z. SHOWERS HAVE ALREADY DEVELOPED ALONG THE
SEA BREEZE JUST WEST OF ILM THIS MORNING. ONCE THE CONVECTIVE TEMP
IS REACHED AROUND 16Z COULD SEE AN ISOLATED THUNDERSTORM DEVELOP
WEST OF ILM/NORTH OF CRE/MYR. COULD ALSO SEE SHOWERS AND POSSIBLY AN
ISOLATED THUNDERSTORM BY 15Z-16Z ALONG THE TROUGH NEAR FLO/LBT. BY
18-19Z LOW-LEVEL MOISTURE DECREASES AS DOES OMEGA AND PVA...SO
SHOULD SEE A DECREASE IN THUNDERSTORM POTENTIAL AT ALL TERMINALS.
BY LATE AFTERNOON/EARLY EVENING THE GFS IS SUGGESTING SOME OF THE
CONVECTION TO THE NORTHWEST OF THE TERMINALS WILL ADVECT INTO THE
FLO/LBT TERMINALS AND DISSIPATE TO MAINLY SHOWERS BY THE TIME IT
REACHES THE COASTAL TERMINALS MID-LATE EVENING. THE NAM KEEPS
PRECIPITATION TO THE NORTHWEST OF FLO/LBT THROUGH 06Z. WILL JUST
INDICATE CB`S FLO/LBT BY 23Z WITH VCSH BY 05Z IN THIS TAF PACKAGE.
EXTENDED OUTLOOK THROUGH SUNDAY...SCATTERED THUNDERSTORMS THURSDAY
AND SUNDAY. ISOLATED THUNDERSTORMS FRIDAY AND SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM WEDNESDAY...SIMILAR TO YESTERDAY...S WINDS WILL BE
CAPPED AT 20 KT OR LESS THIS PERIOD. SE SWELL...PERIODS EVERY 10
SECONDS...AND WIND COMPONENT WILL CONTRIBUTE TO SEA HEIGHTS IN 3 TO
5 FT RANGE.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...SOUTHERLY FLOW WILL CONTINUE THROUGH THE
PERIOD WITH SURFACE HIGH CENTERED EAST OF THE WATERS. GFS WIND
SPEEDS HAVE BEEN OVERDONE FOR THE PAST SEVERAL DAYS AND EXPECT THIS
TREND TO CONTINUE AS LONG AS SOUTHERLY FLOW REMAINS OVER THE WATERS.
PROLONGED PERIOD OF SOUTHERLY FETCH...BETWEEN 10 AND 15 KT FOR MOST
OF THE PERIOD...WILL STEADILY BUILD SEAS. IT IS POSSIBLE THAT SCA
WILL BE NEEDED WITHIN THE FORECAST PERIOD...BUT NOT LIKELY. SEAS
EXPECTED TO REMAIN IN THE 3 TO 5 FT RANGE.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 AM WEDNESDAY...SOUTHERLY FLOW CONTINUES OVER THE WATERS
SAT INTO SUN BUT FRONT DROPPING IN FROM THE NORTH MAY ALLOW
SURFACE HIGH TO THE WEST TO BUILD OVER THE WATERS LATE
SUN...RESULTING IN NORTH TO NORTHWEST FLOW DEVELOPING. CONFIDENCE
IN TIMING OF FRONTAL PASSAGE IS LOW AND SOUTHERLY FLOW COULD END
UP DOMINATING THE LONG TERM PERIOD. GRADIENT BECOMES PINCHED AHEAD
OF FRONT AND SPEEDS MAY INCREASE TO NEAR 20 KT LATER SAT. SEAS WILL
CONTINUE TO RUN 3 TO 5 FT BUT HEADLINE REQUIRING SEAS COULD EASILY
DEVELOP LATER SAT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RJD
SHORT TERM...III
LONG TERM...III
AVIATION...MRR
000
FXUS62 KILM 061144
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
744 AM EDT WED MAY 6 2009
.SYNOPSIS...
A STATIONARY FRONT EXTENDING FROM WEST TO EAST ACROSS CENTRAL NORTH
CAROLINA WILL HELP DEVELOP SHOWERS AND THUNDERSTORMS DURING THE NEXT
FEW DAYS AS WAVES OF LOW PRESSURE DEVELOP AND RIDE ALONG THIS
BOUNDARY. DRIER AIR WILL MAKE ITS WAY INTO THE REGION SATURDAY OR
SUNDAY AS HIGH PRESSURE STARTS TO BUILD INTO THE REGION FROM THE
WEST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM WEDNESDAY...YET ANOTHER SHORT WAVE TROUGH WILL AFFECT THE
AREA THIS AFTERNOON AND TONIGHT...WITH AN ASSOCIATED SURFACE
REFLECTION IN THE FORM OF A LOW PRESSURE WAVE MOVING ALONG THE FRONT
TO OUR NORTHWEST. BEST LIFT APPEARS THAT IT WILL ARRIVE LATE THIS
AFTERNOON AND CONTINUE INTO TONIGHT. GREATEST WINDOW OF OPPORTUNITY
FOR PRECIPITATION COULD BE ROUGHLY 21Z TO 06Z BUT SHOWERS AND STORMS
COULD OCCUR AT ANY TIME TODAY AND TONIGHT AFTER ABOUT 15Z OR SO.
SOME STORMS COULD BE STRONG TO SEVERE AGAIN TODAY. MAXIMUMS SHOULD
REACH THE LOW TO MID 80S WITH LOWS TONIGHT IN THE MID TO UPPER 60S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...FLAT 5H PATTERN WILL LIMIT SOUTHWARD ADVANCE
OF FRONT STALLED NORTH AND WEST OF THE AREA. WEAK SHORTWAVE TROF
CROSSING THE AREA AT THE START OF THE PERIOD MAY BE ABLE TO GET SOME
PRECIP GOING...BUT THIS WILL BE DEPENDANT ON LOCATION AND STRENGTH
OF PVA...SOMETHING THE GUIDANCE HAS BEEN HAVING A LOT OF TROUBLE
WITH LATELY. LATEST GFS MOVES A SECOND SHORTWAVE OUT OF THE EASTERN
GULF COAST REGION INTO THE AREA LATER THU. THE 00Z NAM/CANADIAN AND
12Z ECMWF DO NOT HAVE THIS FEATURE AND IT APPEARS TO BE FEEDBACK.
APPEARS THE ONLY MECHANISM FOR STORM DEVELOPMENT THU AFTERNOON WILL
BE SEA BREEZE AND DIURNAL INSTABILITY.
FORECAST SOUNDINGS SHOW MID LEVEL DRY AIR MOVING IN FROM THE WEST
THU NIGHT INTO FRI. DRY AIR REMAINS OVER THE AREA THROUGH THE END OF
THE PERIOD AND...COMBINED WITH LACK OF DYNAMICS...WILL KEEP PRECIP
CHANCES LOW. WENT WITH SLIGHT CHANCE POPS AS SEA BREEZE AND WEAK
PIEDMONT TROF WILL LIKELY BE THE BEST SOURCES OF CONVECTION.
TEMPERATURES WILL CONTINUE TO RUN NEAR OR SLIGHTLY ABOVE CLIMO
DURING THE DAY AND 5 TO 10 DEGREES ABOVE CLIMO BY NIGHT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 3 AM WEDNESDAY...UPPER PATTERN REMAINS RELATIVELY FLAT
THROUGH THE PERIOD WITH GUIDANCE HINTING AT 5H RIDGE STARTING TO
DEVELOP LATE IN THE PERIOD. IT SHOULD BE NOTED THAT BOTH THE
GFS/ECMWF WERE DOING THIS EARLIER IN THE WEEK ONLY TO BACK OFF A
FEW DAYS LATER. FLATTER UPPER PATTERN WILL KEEP WEATHER ACROSS THE
AREA UNSETTLED AS STALLED SURFACE BOUNDARY REMAINS IN THE AREA
AND SHORTWAVE TROF PASS FROM TIME TO TIME. TIMING THE WAVES AT
LONGER TIME PERIOD IS DIFFICULT AT BEST. SURFACE BOUNDARY DOES
EVENTUALLY PUSH SOUTH OF THE AREA...BUT STILL NOT A LOT OF
AGREEMENT ON WHEN. BEST GUESS IS SUN BUT COULD END UP BEING ON
MON. ONCE THE BOUNDARY IS SOUTH OF THE AREA IT WILL STALL BEFORE
TRYING TO RETURN NORTH AS A WARM FRONT BY THE END OF THE PERIOD.
TEMPERATURES PRE FRONT WILL REMAIN NEAR TO ABOVE CLIMO WITH NEAR
TO SLIGHTLY BELOW CLIMO TEMPS POST FRONT.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
A STATIONARY FRONT IS LOCATED SOUTHWEST TO NORTHEAST ACROSS CENTRAL
NC. A WEAK PRESSURE TROUGH IS LOCATED FROM FLO-LBT. TERMINALS ARE
CURRENTLY VFR WITH TEMPO MVFR CEILINGS OCCURRING. THIS SHOULD BE THE
CASE THROUGH 15-16Z. WINDS TODAY WILL BECOME SOUTH TO SOUTHWEST AT
10-20 KNOTS WITH POSSIBLY HIGHER GUSTS AT TIMES.
THE BEST AREA FOR THUNDERSTORM DEVELOPMENT WILL BE ALONG THE
STATIONARY FRONT TO THE NORTH OF THE TERMINALS. FORECAST STEERING
FLOW/FRONTAL POSITIONS SUGGESTS THIS ACTIVITY WILL STAY WELL NORTH
AND NORTHWEST OF THE FLO/LBT TERMINALS THROUGH THE AFTERNOON. BEST
OMEGAS/LOW LEVEL MOISTURE THROUGH 85H/PVA WILL BE NEAR ILM...AND
FROM FLO-LBT THROUGH 18Z. SHOWERS HAVE ALREADY DEVELOPED ALONG THE
SEA BREEZE JUST WEST OF ILM THIS MORNING. ONCE THE CONVECTIVE TEMP
IS REACHED AROUND 16Z COULD SEE AN ISOLATED THUNDERSTORM DEVELOP
WEST OF ILM/NORTH OF CRE/MYR. COULD ALSO SEE SHOWERS AND POSSIBLY AN
ISOLATED THUNDERSTORM BY 15Z-16Z ALONG THE TROUGH NEAR FLO/LBT. BY
18-19Z LOW-LEVEL MOISTURE DECREASES AS DOES OMEGA AND PVA...SO
SHOULD SEE A DECREASE IN THUNDERSTORM POTENTIAL AT ALL TERMINALS.
BY LATE AFTERNOON/EARLY EVENING THE GFS IS SUGGESTING SOME OF THE
CONVECTION TO THE NORTHWEST OF THE TERMINALS WILL ADVECT INTO THE
FLO/LBT TERMINALS AND DISSIPATE TO MAINLY SHOWERS BY THE TIME IT
REACHES THE COASTAL TERMINALS MID-LATE EVENING. THE NAM KEEPS
PRECIPITATION TO THE NORTHWEST OF FLO/LBT THROUGH 06Z. WILL JUST
INDICATE CB`S FLO/LBT BY 23Z WITH VCSH BY 05Z IN THIS TAF PACKAGE.
EXTENDED OUTLOOK THROUGH SUNDAY...SCATTERED THUNDERSTORMS THURSDAY
AND SUNDAY. ISOLATED THUNDERSTORMS FRIDAY AND SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM WEDNESDAY...EXPECT TO SEE S TO SW WINDS AROUND 15 KT
TODAY AND TONIGHT WITH SEAS RUNNING 3 TO 5 FEET. SCATTERED
THUNDERSTORMS ARE POSSIBLE...ESPECIALLY LATER TODAY INTO TONIGHT.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...SOUTHERLY FLOW WILL CONTINUE THROUGH THE
PERIOD WITH SURFACE HIGH CENTERED EAST OF THE WATERS. GFS WIND
SPEEDS HAVE BEEN OVERDONE FOR THE PAST SEVERAL DAYS AND EXPECT THIS
TREND TO CONTINUE AS LONG AS SOUTHERLY FLOW REMAINS OVER THE WATERS.
PROLONGED PERIOD OF SOUTHERLY FETCH...BETWEEN 10 AND 15 KT FOR MOST
OF THE PERIOD...WILL STEADILY BUILD SEAS. IT IS POSSIBLE THAT SCA
WILL BE NEEDED WITHIN THE FORECAST PERIOD...BUT NOT LIKELY. SEAS
EXPECTED TO REMAIN IN THE 3 TO 5 FT RANGE.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 AM WEDNESDAY...SOUTHERLY FLOW CONTINUES OVER THE WATERS
SAT INTO SUN BUT FRONT DROPPING IN FROM THE NORTH MAY ALLOW
SURFACE HIGH TO THE WEST TO BUILD OVER THE WATERS LATE
SUN...RESULTING IN NORTH TO NORTHWEST FLOW DEVELOPING. CONFIDENCE
IN TIMING OF FRONTAL PASSAGE IS LOW AND SOUTHERLY FLOW COULD END
UP DOMINATING THE LONG TERM PERIOD. GRADIENT BECOMES PINCHED AHEAD
OF FRONT AND SPEEDS MAY INCREASE TO NEAR 20 KT LATER SAT. SEAS WILL
CONTINUE TO RUN 3 TO 5 FT BUT HEADLINE REQUIRING SEAS COULD EASILY
DEVELOP LATER SAT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RAN
SHORT TERM...III
LONG TERM...III
AVIATION...MRR
000
FXUS62 KRAH 061132
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
731 AM EDT WED MAY 6 2009
.SYNOPSIS...
A STATIONARY FRONT OVER CENTRAL NC WILL GRADUALLY WEAKEN AND
DISSIPATE TODAY. AN UPPER LEVEL TROUGH AND ATTENDANT SURFACE TROUGH
WILL PUSH EAST ACROSS CENTRAL NC LATE WEDNESDAY NIGHT THROUGH
THURSDAY MORNING...BRINING ANOTHER ROUND OF SHOWERS AND STORMS TO
NORTH CAROLINA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM WEDNESDAY...
MOST IMMINENT FORECAST CHALLENGE PERTAINS TO THE POSSIBILITY FOR
DENSE FOG THIS MORNING AS A NEARLY SATURATED AIRMASS ALONG A
STATIONARY FRONT ZONE ACROSS CENTRAL NC WILL MAKE FOR FAVORABLE
CONDITIONS. LATEST IR IMAGERY IS SHOWING SIGNIFICANT BREAKS IN MID
AND HIGH CLOUDS ACROSS THE AREA...WHICH COULD RESULT IN SOME
SUFFICIENT BL COOLING. A COUPLE OF REPORTING SITES ARE REPORTING
ONE HALF TO ONE QUARTER OF A MILE VISIBILITY RESTRICTIONS..
SO BEFORE IT IS ALL SAID AND DONE...MAY HAVE TO ISSUE A SHORT-FUSE
DENSE FOG ADVISORY FOR PORTIONS OF THE FORECAST AREA. WILL CONTINUE
TO MONITOR FOR THE NEXT COUPLE OF HOURS AND ISSUE AS NEEDED.
FOR THE REST OF TODAY AND TONIGHT...ANOTHER ROUND OF STORMS...OR
EVEN PERHAPS TWO...ARE EXPECTED THIS AFTERNOON AND OVERNIGHT AS THE
SFC BOUNDARY IS FORECAST TO WEAKEN AND LIFT NORTH THIS AFTERNOON IN
RESPONSE TO AN APPROACHING UPPER LEVEL TROUGH AND ATTENDANT SURFACE
TROUGH FROM THE WEST. MODELS HAVE TRENDED SLOWER AND SLIGHTLY
STRONGER WITH THE PASSAGE OF THE DIGGING UPPER WAVE...WITH IT NOW
FORECAST TO REMAIN WEST OF THE MTNS THROUGH 06Z THURSDAY...SWINGING
EAST ACROSS CENTRAL NC BETWEEN 12 TO 18Z.
THE FIRST ROUND OF CONVECTION LOOKS TO DEVELOP THIS
AFTERNOON...PRIMARILY DRIVEN BY DIFFERENTIAL HEATING AS THE BOUNDARY
WEAKENS AND LIFTS NORTH ACROSS THE AREA...WITH NO DISCERNIBLE
UPPER LEVEL SUPPORT...AS COMPARED TO PAST COUPLE OF DAYS. DEEP LAYER
SHEAR OF 30 TO 40 KTS WITH SBCAPE OF 800 TO 1200 JOULES FROM US 1
SOUTH AND EAST WILL SUPPORT A SLIGHT RISK OF SEVERE STORMS WITH THE
MAJOR THREAT BEING STRONG DAMAGING WINDS AND HAIL AS LARGE NICKEL TO
QUARTER SIZE HAIL AS WET-BULB ZEROS ARE FORECAST TO REMAIN PRETTY
HIGH...AOA 11.5KFT. A MUCH SMALLER...ISOLATED TORNADO THREAT COULD
EXIST AS WELL...IF THE FRONT MANAGES TO LINGER OR HOLD ON LONGER AS
THE NAM SUGGESTS...BETWEEN 18 TO 21Z (THE GFS LIFTS THE FRONT TO THE
NORTH FASTER THAN THE NAM). BUT THE GREATEST SEVERE THREAT AND HIGHER
POPS WILL ARRIVE IN THE EVENING AND OVERNIGHT HOURS WITH THE DIGGING
UPPER WAVE...WITH STRONG JET SUPPORT...BOTH ALOFT AND IN THE
LOW-LEVELS...ACCOMPANYING THE UPPER WAVE AS IT TRAVERSES WEST TO TO
EAST ACROSS THE REGION. CONCEPTUAL RECOGNITION WOULD SUGGEST A
LINEAR SQUALL LINE MOVING THROUGH THE AREA BETWEEN MIDNIGHT THROUGH
DAYBREAK THURSDAY MORNING...WITH VERTICAL SHEAR INCREASING TO 45 TO
50 KTS WITH MORE THAN ADEQUATE INSTABILITY AS MODELS SHOW 800 TO
1000 J/KG OF MUCAPE WITH 700 TO 500MB MID-LEVEL LAPSE RATES OF 7 TO
7.25 ACROSS THE AREA. ADDITIONALLY...ALTHOUGH THE FLOW IS MAINLY
UNIDIRECTIONAL...0 TO 1 KM HELICITY OF 250 TO 300 MS-1 MOVES THROUGH
THE AREA LATE WEDNESDAY NIGHT/THURSDAY MORNING AS SURFACE TROUGH
AND LOW-LEVEL JET MOVES THROUGH THE AREA. IF A SECONDARY MESO-LOW
DEVELOPS ALONG THE TROUGH...AN ISOLATED TORNADO COULD ACCOMPANY THE
THREAT OF STRAIGHT LINE WINDS AND HAIL.
TOUGH TEMPERATURE FORECAST FOR TODAY...DEPENDENT ON THE TIMING
OF THE DISSIPATION OF THE MORNING STRATUS...BUT SHOULD SEE A
SHARP TEMPERATURE GRADIENT ACROSS CENTRAL NC. WILL LEAN TOWARD THE
WARMER MAV GUIDANCE WITH BOUNDARY WEAKENING...AND THUS ALLOWING FOR
THE POTENTIAL TO SEE MORE BREAKS IN CLOUD COVER. HIGHS IN THE LOWER
TO MID 70S NW TO LOWER TO MID 80S SOUTHEAST. LOWS TONIGHT IN THE IN
THE MID TO UPPER 60S.
&&
.SHORT TERM /THURSDAY/...
AS OF 315 AM WEDNESDAY...
THE SLOWER TIMING OF THE PASSAGE OF THE UPPER TROUGH THURSDAY WILL
RESULT IN SCATTERED SHOWERS AND THUNDER EXTENDING WELL INTO THE
AFTERNOON...MAINLY ACROSS THE CENTRAL PIEDMONT AND COASTAL PLAIN
WITH SURFACE TROUGH AND 850-700 THETA-E RIDGE EXTENDING OVER THE
COASTAL PLAIN REGION. STRONG SURFACE HEATING WILL RESULT IN MARGINAL
TO MODEST INSTABILITY OF 1000 TO 1500 JOULES WITH COOLING
TEMPERATURES ALOFT BRINGING AN INCREASE THREAT OF HAIL AS WET-BULB
ZEROES FALL TO AROUND 9KFT ACROSS THE NORTHERN HALF. HIGHS AROUND 80
IN THE NW TO MID 80S SE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
AS OF 340 AM TUESDAY...
ANY REMAINING CONVECTION FROM THURSDAY AFTERNOON SHOULD QUICKLY
DIMINISH DURING THE EVENING WITH THE ONSET OF NOCTURNAL COOLING AND
THE DEPARTURE OF THE MID LEVEL SHORTWAVE. WHILE THE AIRMASS WILL
REMAIN MOIST AND SLIGHTLY UNSTABLE OVERNIGHT...DO NOT SEE ANY
FORCING MECHANISMS AT THIS TIME TO SUPPORT CARRYING POPS PAST THE
EARLY EVENING. IT WILL BE A HUMID AND VERY MILD NIGHT WITH LOWS IN
THE LOW TO MID 60S. PATCHY FOG WILL CERTAINLY BE POSSIBLE GIVEN
DEWPOINTS IN THE 60S AND SOUTHWESTERLY WINDS BECOMING RATHER LIGHT.
THE STATIONARY BOUNDARY OVER THE LOWER MS VALLEY WILL CONTINUE TO
GENERATE WIDESPREAD CONVECTION ACROSS THAT REGION...EXTENDING EAST
INTO THE TN VALLEY ON FRIDAY. IT IS POSSIBLE THAT THIS CONVECTION
COULD GENERATE A MCV THAT THEN TRANSLATES EAST TOWARD OUR REGION
UNDER ZONAL FLOW ALOFT. THE NAM INDICATES THIS IS A POSSIBILITY...
BUT THE GFS AND ECMWF ARE LESS ENTHUSIASTIC. CANNOT HANG OUR HAT ON
THESE POTENTIAL MCVS THIS FAR OUT. SO WITH NO REAL IDENTIFIABLE
TRIGGERS...WE ARE LEFT WITH THE POTENTIAL FOR DIURNALLY DRIVEN
CONVECTION SUPPORTED BY PRECIPITABLE WATERS OVER 1.5 INCHES AND
MLCAPES BETWEEN 1000-2000 J/KG. LOW LEVEL THICKNESSES AND 850 MB
TEMPS SUPPORT HIGHS IN THE 85-88 DEGREE RANGE. WILL KEEP A SLIGHT
CHANCE OF CONVECTION IN THE FORECAST FRIDAY NIGHT GIVEN THE
POTENTIAL FOR A MINOR PERTURBATION TO MOVE THROUGH...INTERACTING
WITH A VERY MOIST AND LINGERING INSTABILITY. LOWS FRI NIGHT 63-67.
A COLD FRONT WILL BEGIN TO APPROACH FROM THE NORTHWEST BY LATE
SATURDAY AFTERNOON AS THE MID LEVEL TROUGH OVER THE GREAT LAKES
BEGINS TO MOVE EAST TOWARD NEW ENGLAND. EXPECT SCATTERED SHOWERS AND
THUNDERSTORMS TO DEVELOP ALONG AND AHEAD OF THE FRONT AS IT
ENCOUNTERS AN UNSTABLE AIRMASS REPRESENTED WITH MLCAPES ABOVE 1000
J/KG. THE BEST MID LEVEL FORCING STAYS WELL TO OUR NORTH...SO WILL
KEEP POPS IN THE CHANCE CATEGORY. THICKNESSES SOAR INTO THE
1410-1415M RANGE...SUPPORTING AT LEAST UPPER 80S FOR HIGHS. WOULD
NOT BE SURPRISED TO SEE SOME LOW 90S IN THE SOUTH AND EAST.
THE FRONT MOVES THROUGH SATURDAY NIGHT WITH A CONTINUED CHANCE FOR
SCATTERED CONVECTION...BUT AS INSTABILITY WANES OVERNIGHT...CHANCES
WILL GRADUALLY DIMINISH. HIGH PRESSURE BEGINS TO BUILD IN FROM THE
NORTH ON SUNDAY...BRINGING A RETURN TO SEASONABLE TEMPS. MODEL
GUIDANCE ALL OVER THE PLACE ON HOW FAR SOUTH THE FRONT MAKES IT AND
ANY POTENTIAL OVERRUNNING PRECIP OVER CENTRAL NC. WILL KEEP THE
FORECAST DRY FOR NOW AND AWAIT A BETTER CONSENSUS.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 730 AM WEDNESDAY...
A NEARLY SATURATED AIRMASS REMAINS IN PLACE OVER CENTRAL NC AS A
STALLED FRONT OVER CENTRAL NC IS EXPECTED TO GRADUALLY WEAKEN TODAY
AS IT LIFTS NORTH OF THE AREA. THE WIDESPREAD LIFR CEILINGS ALONG
AND NORTH OF THE FRONT...AND THE MVFR CEILINGS SOUTH OF THE FRONT
WILL BE SLOW TO LIFT...WITH THE LATEST SREF SHOWING IFR CEILINGS
LINGERING THROUGH 15Z TO 16Z IN THE VICINITY OF THE DISSIPATING
FRONTAL ZONE ACROSS THE NORTHERN AND CENTRAL PIEDMONT. BY 18 TO 21Z
CEILINGS ACROSS SOUTHERN PORTIONS SHOULD IMPROVE TO VFR...WITH MVFR
ACROSS THE FAR NORTH. DIFFERENTIAL AFTERNOON HEATING COMBINED WITH
POSSIBLE MCS OUTFLOW WILL SUPPORT SCATTERED SHOWERS AND
THUNDERSTORMS WITH CONVECTION EXPECTED TO PERSIST WELL INTO THE
NIGHT AS AN UPPER LEVEL DISTURBANCE AND SURFACE TROUGH CROSSES THE
REGION FROM WEST TO EAST OVERNIGHT. THUS EXPECT SIGNIFICANT AVIATION
IMPACTS OF IFR TO MVFR CEILINGS TO CONTINUE THROUGH 12Z THURSDAY.
SHOWERS COULD LINGER INTO THE AFTERNOON ACROSS EASTERN NC AS SURFACE
TROUGH LINGERS ACROSS THE REGION. UNSETTLED WEATHER AND PERIODS OF
ADVERSE AVIATION CONDITIONS COULD RETURN AS EARLY AS
SATURDAY...PERSISTING INTO THE WEEKEND AS ANOTHER FRONT APPROACHES
FROM THE WEST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...CBL
SHORT TERM...CBL
LONG TERM...JFB
AVIATION...CBL
000
FXUS62 KMHX 060929
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
529 AM EDT WED MAY 6 2009
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN NORTHWEST OF THE AREA THROUGH THE
END OF THE WEEK. SEVERAL AREAS OF LOW PRESSURE WILL LIFT NORTHEAST
ALONG THE FRONT INTO THIS WEEKEND. HIGH PRESSURE BUILDS IN FROM
THE NORTHWEST LATE IN THE WEEKEND AND EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ALTHO A MOIST AND MARGINALLY UNSTABLE AIRMASS STILL IN PLACE
OVER EASTERN NC TODAY...EXPECTING OVERALL LESS PCPN/CONVECTIVE
COVERAGE THAN YESTERDAY. FRONTAL BNDRY HAS STALLED JUST TO NW OF
FCST AREA THIS MORNING AND WILL BE SLOWLY RETREATING BACK NORTH AS
A WEAK UPR IMPULSE LIFTS NE ACRS THE MID ATLC REGION TODAY. NOT
EXPECTING MUCH PCPN THIS MORN WITH LTL TO TRIGGER CONVECTION BUT
SHUD PICK UP IN COVERAGE AND INTENSITY WITH DIURNAL HEATING AND
PASSING OF SHORT WAVE TO NW. BEST PCPN CHCS WILL RESIDE ACRS FAR
NW COUNTIES IN VCNTY OF RETREATING FRONT WITH REDUCED CHCS TO SE
WHERE FORCING WILL BE WEAKER. THERE IS STILL A THREAT FOR SEVERE
WEATHER TODAY...AGAIN WITH BEST CHCS OVR NW AREAS WHERE STABILITY
AND VERTICAL SHEAR WILL BE MAXIMIZED. HEAVY PCPN ALSO LIKELY IN
THE STRONGER STORMS WITH PRECIP WATERS ARND 1.5 INCHES WHICH CUD
LEAD TO LOCALIZED FLOODING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
A STRONGER MID LVL TROF CURRENTLY OVR THE SOUTHERN PLAINS WILL BE
APPROACHING THE FCST AREA LATE TNGT. SHUD SEE WANING CONVECTION
WITH DIURNAL HEAT LOSS DURING THE EVENING THEN RENEWED CONVECTION
LATE TNGT INTO EARLY THU ASSOCD WITH THE MID LVL FORCING. THIS
DEPICTED FAIRLY WELL IN NAM/ECMWF MODELS WITH THE OPERATIONAL
GFS...WHICH INITIALIZE POORLY TO BEGIN WITH...AN UNRELIABLE
OUTLIER. THIS CONVECTIVE ACTIVITY LOOKS TO BE COMING THRU DURING
THE DIURNALLY UNFAVORABLE TIME OF DAY BUT CANT RULE OUT
ADDITIONAL SVR WEATHER THREAT LATER TNGT INTO EARLY THU GIVEN THE
STRONG MID/UPPER LVL SUPPORT. MAY SEE BULK OF PCPN MOVING OFF THE
COAST BY ARND MIDDAY THURS WITH SUBSIDENCE/DRYING IN THE WAKE OF
THE MID LVL TROF LEADING TO LOWER PCPN CHCS DURING THE AFTN.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
A PERIOD OF LESSER PCPN CHCS/COVERAGE APPEARS TO BE DEVELOPING
EARLY THIS FCST PERIOD AS THE LINGERING FRONT TO NW MOVES FARTHER
NORTH AND MID LVL FLOW BECOMES MORE ZONAL. HARD TO COMPLETELY
RULE OUT POPS GIVEN THE CONTINUED HIGH DEW POINTS AND POTENTIAL
FOR ANY WEAK MID LVL DISTURBANCE TO SET OFF CONVECTION ALONG
RESIDUAL MESOSCALE BNDYS. SHUD SEE MORE SUN ON FRI WHICH WILL HELP
BOOST TEMPS WELL INTO 80S AND POSSBLY NEAR 90 INLAND. MID LVL
ENERGY DROPPING SE THRU THE MIDWEST WILL PROPEL THE LINGERING SFC
BNDRY ACRS THE MID ATLC REGION DURING THE FIRST HALF OF THE
WEEKEND WITH RENEWED INCREASED CHCS FOR PCPN ON SATURDAY. THE
FRONT MAY SLOW DOWN AND STALL NEAR OR SOUTH OF THE AREA DURING THE
SECOND HALF OF THE WEEKEND SO WILL CONTINUE LOW PCPN CHCS INTO
SUNDAY. IT LOOKS AS IF THE FRONT WILL FINALLY PUSH WELL SOUTH OF
THE AREA AS ADDITIONAL NORTHERN STREAM ENERGY LOADS THE MID LVL
TROF OFF THE EASTERN SEABOARD. WITH SFC HIGH PRES BUILDING IN FROM
THE NORTH MAY FINALLY SEE AN END TO THE RECENT WET/UNSETTLED
WEATHER PERIOD EARLY NEXT WEEK.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
A PERSISTENT WEATHER PATTERN CONTINUES ACROSS RTES TODAY WITH A
FRONT STALLED JUST NW OF RTES. SOUTHERLY FLOW BRINGING ABUNDANT
MOISTURE BUT LOWEST CIGS GENERALLY REMAINING ON THE NW SIDE OF THE
FRONT. CIGS EARLY THIS MORNING HAVE PREDOMINATELY BEEN VFR BUT
HAVE BRIEFLY DROPPED TO IFR AT ISO AND PGV EARLIER THIS MORNING.
NAM GUIDANCE CONTINUES TO BE TREMENDOUSLY OVERDONE BRINGING LIFR
CIGS TO ALL TERMINALS AND HAVE TRENDED CLOSER TO GFS GUIDANCE
WHICH LIMITS CIGS TO MVFR THIS MORNING. CONVECTION LIKELY AGAIN
TODAY WITH GREATEST COVERAGE EXPECTED CLOSE TO THE FRONT...NEAR
THE I-95 CORRIDOR...BUT CANNOT RULE OUT ANYWHERE ACROSS RTES. LOW
PRES PASSING NW OF RTES WILL SERVE TO LIFT THE FRONT N OF THE
REGION...THEN A TRAILING FRONT WILL MOVE BACK INTO THE REGION LATE
TONIGHT AND THU.
MOIST SLY FLOW WITH A FRONTAL BOUNDARY IN THE VICINITY WILL
CONTINUE TO BRING THE THREAT OF SHOWERS AND THUNDERSTORMS THROUGH
THE REMAINDER OF THE WEEK.
&&
.MARINE...
SOUTHERLY FLOW CONTINUES ACROSS THE WATERS WITH THE BERMUDA HIGH
ACROSS THE WRN ATLANTIC AND STALLED FRONT ACROSS CENTRAL NC. WINDS
GENERALLY 15 KT OR LESS WITH SEAS MAINLY 3 TO 5 FT...HOWEVER THE
CENTRAL WATERS REPORTING UP TO 6 FT AND WILL CONTINUE THE SCA
ACROSS THE CENTRAL WATERS TODAY. AN AREA OF LOW PRES WILL LIFT NE
ACROSS THE APPALACHIANS LATER TODAY AND TONIGHT AND WILL BRING
TIGHTER GRADIENTS ACROSS THE WATERS BRINGING INCREASED WINDS AND
SEAS. WAVEWATCH LOOKS ON TRACK AND FOLLOWED CLOSELY THROUGH THE
FORECAST. EXPECTING SEAS UP TO 6 FT TO MOVE INTO THE OUTER PORTIONS
OF THE WATERS S OF OCRACOKE INLET AND N OF OREGON INLET LATE THIS
AFTERNOON AS SLY FLOW INCREASES AND HAVE SCA STARTING AT 4 PM FOR
THOSE ZONES. WINDS EXPECTED TO INCREASE TO AROUND 25 KT ACROSS
MOST OF THE WATERS AFTER MIDNIGHT TONIGHT AND CONTINUE THROUGH THU
MORNING AND HAVE SCA IN THE SOUNDS FOR THIS PERIOD. GRADIENTS
RELAX A BIT LATE THU WITH WINDS DROPPING BELOW SCA CONDITIONS
HOWEVER WAVEWATCH CONTINUES TO BRING SEAS UP TO 6-7 FT ACROSS THE
CENTRAL AND SOUTHERN WATERS THROUGH THE REST OF THE WEEK WITH A
LONG AND PERSISTENT SOUTHERLY FETCH INTO THE REGION. THE PATTERN
LOOKS TO FINALLY BREAK DOWN LATE THIS WEEKEND WITH A FRONT PUSHING
THROUGH THE WATERS AND HIGH PRES BUILDING IN FROM THE NW.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM TO 2 PM EDT THURSDAY FOR AMZ130-
135.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT SUNDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 2 PM EDT
SUNDAY FOR AMZ156-158.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 4 PM EDT
THURSDAY FOR AMZ150.
&&
$$
SYNOPSIS...BTC
NEAR TERM...BTC
SHORT TERM...BTC
LONG TERM...BTC
AVIATION...SK
MARINE...SK
000
FXUS62 KMHX 060754
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
354 AM EDT WED MAY 6 2009
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN NORTHWEST OF THE AREA THROUGH THE
END OF THE WEEK. SEVERAL AREAS OF LOW PRESSURE WILL LIFT NORTHEAST
ALONG THE FRONT INTO THIS WEEKEND. HIGH PRESSURE BUILDS IN FROM
THE NORTHWEST LATE IN THE WEEKEND AND EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ALTHO A MOIST AND MARGINALLY UNSTABLE AIRMASS STILL IN PLACE
OVER EASTERN NC TODAY...EXPECTING OVERALL LESS PCPN/CONVECTIVE
COVERAGE THAN YESTERDAY. FRONTAL BNDRY HAS STALLED JUST TO NW OF
FCST AREA THIS MORNING AND WILL BE SLOWLY RETREATING BACK NORTH AS
A WEAK UPR IMPULSE LIFTS NE ACRS THE MID ATLC REGION TODAY. NOT
EXPECTING MUCH PCPN THIS MORN WITH LTL TO TRIGGER CONVECTION BUT
SHUD PICK UP IN COVERAGE AND INTENSITY WITH DIURNAL HEATING AND
PASSING OF SHORT WAVE TO NW. BEST PCPN CHCS WILL RESIDE ACRS FAR
NW COUNTIES IN VCNTY OF RETREATING FRONT WITH REDUCED CHCS TO SE
WHERE FORCING WILL BE WEAKER. THERE IS STILL A THREAT FOR SEVERE
WEATHER TODAY...AGAIN WITH BEST CHCS OVR NW AREAS WHERE STABILITY
AND VERTICAL SHEAR WILL BE MAXIMIZED. HEAVY PCPN ALSO LIKELY IN
THE STRONGER STORMS WITH PRECIP WATERS ARND 1.5 INCHES WHICH CUD
LEAD TO LOCALIZED FLOODING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
A STRONGER MID LVL TROF CURRENTLY OVR THE SOUTHERN PLAINS WILL BE
APPROACHING THE FCST AREA LATE TNGT. SHUD SEE WANING CONVECTION
WITH DIURNAL HEAT LOSS DURING THE EVENING THEN RENEWED CONVECTION
LATE TNGT INTO EARLY THU ASSOCD WITH THE MID LVL FORCING. THIS
DEPICTED FAIRLY WELL IN NAM/ECMWF MODELS WITH THE OPERATIONAL
GFS...WHICH INITIALIZE POORLY TO BEGIN WITH...AN UNRELIABLE
OUTLIER. THIS CONVECTIVE ACTIVITY LOOKS TO BE COMING THRU DURING
THE DIURNALLY UNFAVORABLE TIME OF DAY BUT CANT RULE OUT
ADDITIONAL SVR WEATHER THREAT LATER TNGT INTO EARLY THU GIVEN THE
STRONG MID/UPPER LVL SUPPORT. MAY SEE BULK OF PCPN MOVING OFF THE
COAST BY ARND MIDDAY THURS WITH SUBSIDENCE/DRYING IN THE WAKE OF
THE MID LVL TROF LEADING TO LOWER PCPN CHCS DURING THE AFTN.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
A PERIOD OF LESSER PCPN CHCS/COVERAGE APPEARS TO BE DEVELOPING
EARLY THIS FCST PERIOD AS THE LINGERING FRONT TO NW MOVES FARTHER
NORTH AND MID LVL FLOW BECOMES MORE ZONAL. HARD TO COMPLETELY
RULE OUT POPS GIVEN THE CONTINUED HIGH DEW POINTS AND POTENTIAL
FOR ANY WEAK MID LVL DISTURBANCE TO SET OFF CONVECTION ALONG
RESIDUAL MESOSCALE BNDYS. SHUD SEE MORE SUN ON FRI WHICH WILL HELP
BOOST TEMPS WELL INTO 80S AND POSSBLY NEAR 90 INLAND. MID LVL
ENERGY DROPPING SE THRU THE MIDWEST WILL PROPEL THE LINGERING SFC
BNDRY ACRS THE MID ATLC REGION DURING THE FIRST HALF OF THE
WEEKEND WITH RENEWED INCREASED CHCS FOR PCPN ON SATURDAY. THE
FRONT MAY SLOW DOWN AND STALL NEAR OR SOUTH OF THE AREA DURING THE
SECOND HALF OF THE WEEKEND SO WILL CONTINUE LOW PCPN CHCS INTO
SUNDAY. IT LOOKS AS IF THE FRONT WILL FINALLY PUSH WELL SOUTH OF
THE AREA AS ADDITIONAL NORTHERN STREAM ENERGY LOADS THE MID LVL
TROF OFF THE EASTERN SEABOARD. WITH SFC HIGH PRES BUILDING IN FROM
THE NORTH MAY FINALLY SEE AN END TO THE RECENT WET/UNSETTLED
WEATHER PERIOD EARLY NEXT WEEK.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
AS OF 10 PM...MVFR CIGS HAVE DEVELOPED OVER EASTERN TERMINALS
THIS EVENING WHILE WESTERN TERMINALS REMAIN VFR. SOME SHRA
POSSIBLE OVER THE WESTERN TERMINALS THIS EVENING AS CONVECTION
DIMINISHES JUST WEST OF THE AREA OTHERWISE EXPECT MVFR CIGS TO
DEVELOP AND LOWER TO IFR ALL TERMINALS OVERNIGHT. SOME FOG IS ALSO
POSSIBLE LATE TONIGHT BUT WINDS WILL NOT DECOUPLE SO VSBYS NOT
EXPECTED TO DROP BELOW MVFR.
LOOK FOR ANOTHER ROUND OF CONVECTION WED WITH VERY LITTLE OVERALL
CHANGE IN AIRMASS UNTIL LATE WEEKEND WHEN A FRONT PUSHES THROUGH
THE REGION.
&&
.MARINE...
AS OF 10 PM...MADE MINOR TWEAKS TO WINDS THIS UPDATE OTHERWISE
LITTLE CHANGE TO CURRENT FORECAST. SEAS NOW 6 FT AT DIAMOND BUOY
AND WW3 GUIDANCE CONTINUES TO INDICATE 6 FT SEAS DEVELOPING OVER
EASTERN PORTIONS OF THE CENTRAL/SOUTHERN WATERS OVERNIGHT AS
PERSISTENT SW WINDS CONTINUE. SCA NOW IN EFFECT ACROSS THESE
WATERS OVERNIGHT INTO WEDNESDAY. BY THU THE UPPER TROF PUSHES INTO
THE SE...AND THE SFC FRONT SAGS S AS WELL. UNFORTUNATELY IT WASHES
OUT AND WE CONTINUE IN A SW FLOW INTO SAT. BY SUNDAY THE UPPER
TROF IS REINFORCED...A SFC HIGH SLIDES OUT OF CANADA...AND A COLD
FRONT FINALLY PUSHES THROUGH THE REGION. OVERALL NO NOTABLE SWELLS
OUTSIDE OF THE BUILDING SW...SO SEAS WILL LIKELY SUBSIDE QUICKLY
WITH A WIND SHIFT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THURSDAY FOR AMZ152-154-
156.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR AMZ158.
&&
$$
SYNOPSIS...BTC
NEAR TERM...BTC
SHORT TERM...BTC
LONG TERM...BTC
AVIATION...SJ/JW
MARINE...SJ/JW
000
FXUS62 KRAH 060743
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
343 AM EDT WED MAY 6 2009
.SYNOPSIS...
A STATIONARY FRONT OVER CENTRAL NC WILL GRADUALLY WEAKEN AND
DISSIPATE TODAY. AN UPPER LEVEL TROUGH AND ATTENDANT SURFACE TROUGH
WILL PUSH EAST ACROSS CENTRAL NC LATE WEDNESDAY NIGHT THROUGH
THURSDAY MORNING...BRINING ANOTHER ROUND OF SHOWERS AND STORMS TO
NORTH CAROLINA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM WEDNESDAY...
MOST IMMINENT FORECAST CHALLENGE PERTAINS TO THE POSSIBILITY FOR
DENSE FOG THIS MORNING AS A NEARLY SATURATED AIRMASS ALONG A
STATIONARY FRONT ZONE ACROSS CENTRAL NC WILL MAKE FOR FAVORABLE
CONDITIONS. LATEST IR IMAGERY IS SHOWING SIGNIFICANT BREAKS IN MID
AND HIGH CLOUDS ACROSS THE AREA...WHICH COULD RESULT IN SOME
SUFFICIENT BL COOLING. A COUPLE OF REPORTING SITES ARE REPORTING
ONE HALF TO ONE QUARTER OF A MILE VISIBILITY RESTRICTIONS..
SO BEFORE IT IS ALL SAID AND DONE...MAY HAVE TO ISSUE A SHORT-FUSE
DENSE FOG ADVISORY FOR PORTIONS OF THE FORECAST AREA. WILL CONTINUE
TO MONITOR FOR THE NEXT COUPLE OF HOURS AND ISSUE AS NEEDED.
FOR THE REST OF TODAY AND TONIGHT...ANOTHER ROUND OF STORMS...OR
EVEN PERHAPS TWO...ARE EXPECTED THIS AFTERNOON AND OVERNIGHT AS THE
SFC BOUNDARY IS FORECAST TO WEAKEN AND LIFT NORTH THIS AFTERNOON IN
RESPONSE TO AN APPROACHING UPPER LEVEL TROUGH AND ATTENDANT SURFACE
TROUGH FROM THE WEST. MODELS HAVE TRENDED SLOWER AND SLIGHTLY
STRONGER WITH THE PASSAGE OF THE DIGGING UPPER WAVE...WITH IT NOW
FORECAST TO REMAIN WEST OF THE MTNS THROUGH 06Z THURSDAY...SWINGING
EAST ACROSS CENTRAL NC BETWEEN 12 TO 18Z.
THE FIRST ROUND OF CONVECTION LOOKS TO DEVELOP THIS
AFTERNOON...PRIMARILY DRIVEN BY DIFFERENTIAL HEATING AS THE BOUNDARY
WEAKENS AND LIFTS NORTH ACROSS THE AREA...WITH NO DISCERNIBLE
UPPER LEVEL SUPPORT...AS COMPARED TO PAST COUPLE OF DAYS. DEEP LAYER
SHEAR OF 30 TO 40 KTS WITH SBCAPE OF 800 TO 1200 JOULES FROM US 1
SOUTH AND EAST WILL SUPPORT A SLIGHT RISK OF SEVERE STORMS WITH THE
MAJOR THREAT BEING STRONG DAMAGING WINDS AND HAIL AS LARGE NICKEL TO
QUARTER SIZE HAIL AS WET-BULB ZEROS ARE FORECAST TO REMAIN PRETTY
HIGH...AOA 11.5KFT. A MUCH SMALLER...ISOLATED TORNADO THREAT COULD
EXIST AS WELL...IF THE FRONT MANAGES TO LINGER OR HOLD ON LONGER AS
THE NAM SUGGESTS...BETWEEN 18 TO 21Z (THE GFS LIFTS THE FRONT TO THE
NORTH FASTER THAN THE NAM). BUT THE GREATEST SEVERE THREAT AND HIGHER
POPS WILL ARRIVE IN THE EVENING AND OVERNIGHT HOURS WITH THE DIGGING
UPPER WAVE...WITH STRONG JET SUPPORT...BOTH ALOFT AND IN THE
LOW-LEVELS...ACCOMPANYING THE UPPER WAVE AS IT TRAVERSES WEST TO TO
EAST ACROSS THE REGION. CONCEPTUAL RECOGNITION WOULD SUGGEST A
LINEAR SQUALL LINE MOVING THROUGH THE AREA BETWEEN MIDNIGHT THROUGH
DAYBREAK THURSDAY MORNING...WITH VERTICAL SHEAR INCREASING TO 45 TO
50 KTS WITH MORE THAN ADEQUATE INSTABILITY AS MODELS SHOW 800 TO
1000 J/KG OF MUCAPE WITH 700 TO 500MB MID-LEVEL LAPSE RATES OF 7 TO
7.25 ACROSS THE AREA. ADDITIONALLY...ALTHOUGH THE FLOW IS MAINLY
UNIDIRECTIONAL...0 TO 1 KM HELICITY OF 250 TO 300 MS-1 MOVES THROUGH
THE AREA LATE WEDNESDAY NIGHT/THURSDAY MORNING AS SURFACE TROUGH
AND LOW-LEVEL JET MOVES THROUGH THE AREA. IF A SECONDARY MESO-LOW
DEVELOPS ALONG THE TROUGH...AN ISOLATED TORNADO COULD ACCOMPANY THE
THREAT OF STRAIGHT LINE WINDS AND HAIL.
TOUGH TEMPERATURE FORECAST FOR TODAY...DEPENDENT ON THE TIMING
OF THE DISSIPATION OF THE MORNING STRATUS...BUT SHOULD SEE A
SHARP TEMPERATURE GRADIENT ACROSS CENTRAL NC. WILL LEAN TOWARD THE
WARMER MAV GUIDANCE WITH BOUNDARY WEAKENING...AND THUS ALLOWING FOR
THE POTENTIAL TO SEE MORE BREAKS IN CLOUD COVER. HIGHS IN THE LOWER
TO MID 70S NW TO LOWER TO MID 80S SOUTHEAST. LOWS TONIGHT IN THE IN
THE MID TO UPPER 60S.
&&
.SHORT TERM /THURSDAY/...
AS OF 315 AM WEDNESDAY...
THE SLOWER TIMING OF THE PASSAGE OF THE UPPER TROUGH THURSDAY WILL
RESULT IN SCATTERED SHOWERS AND THUNDER EXTENDING WELL INTO THE
AFTERNOON...MAINLY ACROSS THE CENTRAL PIEDMONT AND COASTAL PLAIN
WITH SURFACE TROUGH AND 850-700 THETA-E RIDGE EXTENDING OVER THE
COASTAL PLAIN REGION. STRONG SURFACE HEATING WILL RESULT IN MARGINAL
TO MODEST INSTABILITY OF 1000 TO 1500 JOULES WITH COOLING
TEMPERATURES ALOFT BRINGING AN INCREASE THREAT OF HAIL AS WET-BULB
ZEROES FALL TO AROUND 9KFT ACROSS THE NORTHERN HALF. HIGHS AROUND 80
IN THE NW TO MID 80S SE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
AS OF 340 AM TUESDAY...
ANY REMAINING CONVECTION FROM THURSDAY AFTERNOON SHOULD QUICKLY
DIMINISH DURING THE EVENING WITH THE ONSET OF NOCTURNAL COOLING AND
THE DEPARTURE OF THE MID LEVEL SHORTWAVE. WHILE THE AIRMASS WILL
REMAIN MOIST AND SLIGHTLY UNSTABLE OVERNIGHT...DO NOT SEE ANY
FORCING MECHANISMS AT THIS TIME TO SUPPORT CARRYING POPS PAST THE
EARLY EVENING. IT WILL BE A HUMID AND VERY MILD NIGHT WITH LOWS IN
THE LOW TO MID 60S. PATCHY FOG WILL CERTAINLY BE POSSIBLE GIVEN
DEWPOINTS IN THE 60S AND SOUTHWESTERLY WINDS BECOMING RATHER LIGHT.
THE STATIONARY BOUNDARY OVER THE LOWER MS VALLEY WILL CONTINUE TO
GENERATE WIDESPREAD CONVECTION ACROSS THAT REGION...EXTENDING EAST
INTO THE TN VALLEY ON FRIDAY. IT IS POSSIBLE THAT THIS CONVECTION
COULD GENERATE A MCV THAT THEN TRANSLATES EAST TOWARD OUR REGION
UNDER ZONAL FLOW ALOFT. THE NAM INDICATES THIS IS A POSSIBILITY...
BUT THE GFS AND ECMWF ARE LESS ENTHUSIASTIC. CANNOT HANG OUR HAT ON
THESE POTENTIAL MCVS THIS FAR OUT. SO WITH NO REAL IDENTIFIABLE
TRIGGERS...WE ARE LEFT WITH THE POTENTIAL FOR DIURNALLY DRIVEN
CONVECTION SUPPORTED BY PRECIPITABLE WATERS OVER 1.5 INCHES AND
MLCAPES BETWEEN 1000-2000 J/KG. LOW LEVEL THICKNESSES AND 850 MB
TEMPS SUPPORT HIGHS IN THE 85-88 DEGREE RANGE. WILL KEEP A SLIGHT
CHANCE OF CONVECTION IN THE FORECAST FRIDAY NIGHT GIVEN THE
POTENTIAL FOR A MINOR PERTURBATION TO MOVE THROUGH...INTERACTING
WITH A VERY MOIST AND LINGERING INSTABILITY. LOWS FRI NIGHT 63-67.
A COLD FRONT WILL BEGIN TO APPROACH FROM THE NORTHWEST BY LATE
SATURDAY AFTERNOON AS THE MID LEVEL TROUGH OVER THE GREAT LAKES
BEGINS TO MOVE EAST TOWARD NEW ENGLAND. EXPECT SCATTERED SHOWERS AND
THUNDERSTORMS TO DEVELOP ALONG AND AHEAD OF THE FRONT AS IT
ENCOUNTERS AN UNSTABLE AIRMASS REPRESENTED WITH MLCAPES ABOVE 1000
J/KG. THE BEST MID LEVEL FORCING STAYS WELL TO OUR NORTH...SO WILL
KEEP POPS IN THE CHANCE CATEGORY. THICKNESSES SOAR INTO THE
1410-1415M RANGE...SUPPORTING AT LEAST UPPER 80S FOR HIGHS. WOULD
NOT BE SURPRISED TO SEE SOME LOW 90S IN THE SOUTH AND EAST.
THE FRONT MOVES THROUGH SATURDAY NIGHT WITH A CONTINUED CHANCE FOR
SCATTERED CONVECTION...BUT AS INSTABILITY WANES OVERNIGHT...CHANCES
WILL GRADUALLY DIMINISH. HIGH PRESSURE BEGINS TO BUILD IN FROM THE
NORTH ON SUNDAY...BRINGING A RETURN TO SEASONABLE TEMPS. MODEL
GUIDANCE ALL OVER THE PLACE ON HOW FAR SOUTH THE FRONT MAKES IT AND
ANY POTENTIAL OVERRUNNING PRECIP OVER CENTRAL NC. WILL KEEP THE
FORECAST DRY FOR NOW AND AWAIT A BETTER CONSENSUS.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 145 AM WEDNESDAY...
A NEARLY SATURATED AIRMASS...ASSOCIATED WITH A STALLED FRONT OVER
CENTRAL NC...WILL RESULT IN LIFR TO VFR CONDITIONS THIS MORNING.
THE IS THE POTENTIAL TO SEE SOME AREAS OF DENSE FOG (VISIBILITIES
ONE QUARTER MILE OR LESS)IF THE SIGNIFICANT BREAKS IN MID AND HIGH
CLOUDS CONTINUE AS INDICATED BY LATEST IR IMAGERY...BUT THE MOST
CRITICAL AVIATION IMPACTS WILL BE PRIMARILY DUE TO THE LOW LIFR
CEILINGS.
THE SREF SHOWS A SLOW BURN OFF OR LIFTING OF MORNING STRATUS/FOG
THIS MORNING...WITH VFR CEILINGS LINGERING THROUGH 15Z TO 16Z IN THE
VICINITY OF THE DISSIPATING FRONTAL ZONE ACROSS THE NORTHERN AND
CENTRAL PIEDMONT...WITH CEILINGS LIFTING TO VFR ACROSS THE SOUTH TO
MVFR ACROSS THE FAR NORTH. DIFFERENTIAL AFTERNOON HEATING WILL
LIKELY SUPPORT SCATTERED SHOWERS AND THUNDERSTORMS WITH CONVECTION
EXPECTED TO PERSIST WELL INTO THE NIGHT AS AN UPPER LEVEL
DISTURBANCE AND SURFACE TROUGH CROSSES THE REGION FROM WEST TO EAST
OVERNIGHT.
SHOWERS COULD LINGER INTO THE AFTERNOON ACROSS EASTERN NC AS SURFACE
TROUGH LINGERS ACROSS THE REGION. UNSETTLED WEATHER AND PERIODS OF
ADVERSE AVIATION CONDITIONS COULD RETURN AS EARLY AS
SATURDAY...PERSISTING INTO THE WEEKEND AS ANOTHER FRONT APPROACHES
FROM THE WEST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...CBL
SHORT TERM...CBL
LONG TERM...JFB
AVIATION...CBL
000
FXUS62 KILM 060727
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
327 AM EDT WED MAY 6 2009
.SYNOPSIS...
A STATIONARY FRONT EXTENDING FROM WEST TO EAST ACROSS CENTRAL NORTH
CAROLINA WILL HELP DEVELOP SHOWERS AND THUNDERSTORMS DURING THE NEXT
FEW DAYS AS WAVES OF LOW PRESSURE DEVELOP AND RIDE ALONG THIS
BOUNDARY. DRIER AIR WILL MAKE ITS WAY INTO THE REGION SATURDAY OR
SUNDAY AS HIGH PRESSURE STARTS TO BUILD INTO THE REGION FROM THE
WEST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM WEDNESDAY...YET ANOTHER SHORT WAVE TROUGH WILL AFFECT THE
AREA THIS AFTERNOON AND TONIGHT...WITH AN ASSOCIATED SURFACE
REFLECTION IN THE FORM OF A LOW PRESSURE WAVE MOVING ALONG THE FRONT
TO OUR NORTHWEST. BEST LIFT APPEARS THAT IT WILL ARRIVE LATE THIS
AFTERNOON AND CONTINUE INTO TONIGHT. GREATEST WINDOW OF OPPORTUNITY
FOR PRECIPITATION COULD BE ROUGHLY 21Z TO 06Z BUT SHOWERS AND STORMS
COULD OCCUR AT ANY TIME TODAY AND TONIGHT AFTER ABOUT 15Z OR SO.
SOME STORMS COULD BE STRONG TO SEVERE AGAIN TODAY. MAXIMUMS SHOULD
REACH THE LOW TO MID 80S WITH LOWS TONIGHT IN THE MID TO UPPER 60S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...FLAT 5H PATTERN WILL LIMIT SOUTHWARD ADVANCE
OF FRONT STALLED NORTH AND WEST OF THE AREA. WEAK SHORTWAVE TROF
CROSSING THE AREA AT THE START OF THE PERIOD MAY BE ABLE TO GET SOME
PRECIP GOING...BUT THIS WILL BE DEPENDANT ON LOCATION AND STRENGTH
OF PVA...SOMETHING THE GUIDANCE HAS BEEN HAVING A LOT OF TROUBLE
WITH LATELY. LATEST GFS MOVES A SECOND SHORTWAVE OUT OF THE EASTERN
GULF COAST REGION INTO THE AREA LATER THU. THE 00Z NAM/CANADIAN AND
12Z ECMWF DO NOT HAVE THIS FEATURE AND IT APPEARS TO BE FEEDBACK.
APPEARS THE ONLY MECHANISM FOR STORM DEVELOPMENT THU AFTERNOON WILL
BE SEA BREEZE AND DIURNAL INSTABILITY.
FORECAST SOUNDINGS SHOW MID LEVEL DRY AIR MOVING IN FROM THE WEST
THU NIGHT INTO FRI. DRY AIR REMAINS OVER THE AREA THROUGH THE END OF
THE PERIOD AND...COMBINED WITH LACK OF DYNAMICS...WILL KEEP PRECIP
CHANCES LOW. WENT WITH SLIGHT CHANCE POPS AS SEA BREEZE AND WEAK
PIEDMONT TROF WILL LIKELY BE THE BEST SOURCES OF CONVECTION.
TEMPERATURES WILL CONTINUE TO RUN NEAR OR SLIGHTLY ABOVE CLIMO
DURING THE DAY AND 5 TO 10 DEGREES ABOVE CLIMO BY NIGHT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 3 AM WEDNESDAY...UPPER PATTERN REMAINS RELATIVELY FLAT
THROUGH THE PERIOD WITH GUIDANCE HINTING AT 5H RIDGE STARTING TO
DEVELOP LATE IN THE PERIOD. IT SHOULD BE NOTED THAT BOTH THE
GFS/ECMWF WERE DOING THIS EARLIER IN THE WEEK ONLY TO BACK OFF A
FEW DAYS LATER. FLATTER UPPER PATTERN WILL KEEP WEATHER ACROSS THE
AREA UNSETTLED AS STALLED SURFACE BOUNDARY REMAINS IN THE AREA
AND SHORTWAVE TROF PASS FROM TIME TO TIME. TIMING THE WAVES AT
LONGER TIME PERIOD IS DIFFICULT AT BEST. SURFACE BOUNDARY DOES
EVENTUALLY PUSH SOUTH OF THE AREA...BUT STILL NOT A LOT OF
AGREEMENT ON WHEN. BEST GUESS IS SUN BUT COULD END UP BEING ON
MON. ONCE THE BOUNDARY IS SOUTH OF THE AREA IT WILL STALL BEFORE
TRYING TO RETURN NORTH AS A WARM FRONT BY THE END OF THE PERIOD.
TEMPERATURES PRE FRONT WILL REMAIN NEAR TO ABOVE CLIMO WITH NEAR
TO SLIGHTLY BELOW CLIMO TEMPS POST FRONT.
AS OF 3 PM
TUESDAY...FORECAST MODELS CONTINUE TO SHOW A FAST WESTERLY FLOW
THROUGH THE PERIOD. SHORTWAVES EMBEDDED IN THIS FLOW WILL TRIGGER
INCREASED CONVECTION...BUT TIMING OF THESE FEATURES IN THE
EXTENDED FORECAST PERIOD IS ALWAYS DIFFICULT. ONE SHORT WAVE MAY
AFFECT THE AREA FRIDAY AND ANOTHER LATER SATURDAY. THE PASSAGE OF
SECOND SHORT WAVE SHOULD BRING A COLD FRONT THROUGH THE AREA. THIS
FRONT SHOULD CLEAR OUR FORECAST AREA...BEFORE STALLING TO OUR S.
WILL CONTINUE PREVIOUS FORECAST TRENDS AND BRING DRIER AIR INTO
THE AREA LATE IN THE WEEKEND AND EARLY NEXT WEEK. THE DRIER AIR
WILL BE ACCOMPANIED BY COOLER TEMPS...EVEN WITH FULL SUNSHINE...AS
HIGH PRESSURE OF CANADIAN ORIGIN BUILDS SOUTH.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
AT 05 UTC...THE STATIONARY FRONT CONTINUES TO RUN FROM COASTAL
VIRGINA AND NORTH CAROLINA BORDER TO JUST SOUTH OF CHARLOTTE. THIS
FRONT WILL REMAIN TO THE NORTHWEST OF ALL TAF SITE THROUGH THIS
PERIOD. CONTINUED SHORT WAVES ARE EXPECTED TO RIPPLE ALONG THE FRONT
AND IF INSTABILITY CAN REBOUND OVER THE AREA THUNDERSTORMS WILL
AGAIN DEVELOP ESPECIALLY AFTERNOON WEDNESDAY.
EXPECT POSSIBLE IFR CEILINGS TO DEVELOP WITH WINDS JUST ABOVE THE
BOUNDARY LAYER AND ABUNDANT MOISTURE AFTER 08 UTC...ALSO MVFR
CONDITIONS ARE EXPECTED TO REDEVELOP FOR VSBY AT KLBT AND KFLO.
EXTENDED OUTLOOK THROUGH SUNDAY...SCATTERED AFTERNOON AND EVENING
THUNDERSTORMS EACH AFTERNOON.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM WEDNESDAY...EXPECT TO SEE S TO SW WINDS AROUND 15 KT
TODAY AND TONIGHT WITH SEAS RUNNING 3 TO 5 FEET. SCATTERED
THUNDERSTORMS ARE POSSIBLE...ESPECIALLY LATER TODAY INTO TONIGHT.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...SOUTHERLY FLOW WILL CONTINUE THROUGH THE
PERIOD WITH SURFACE HIGH CENTERED EAST OF THE WATERS. GFS WIND
SPEEDS HAVE BEEN OVERDONE FOR THE PAST SEVERAL DAYS AND EXPECT THIS
TREND TO CONTINUE AS LONG AS SOUTHERLY FLOW REMAINS OVER THE WATERS.
PROLONGED PERIOD OF SOUTHERLY FETCH...BETWEEN 10 AND 15 KT FOR MOST
OF THE PERIOD...WILL STEADILY BUILD SEAS. IT IS POSSIBLE THAT SCA
WILL BE NEEDED WITHIN THE FORECAST PERIOD...BUT NOT LIKELY. SEAS
EXPECTED TO REMAIN IN THE 3 TO 5 FT RANGE.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 AM WEDNESDAY...SOUTHERLY FLOW CONTINUES OVER THE WATERS
SAT INTO SUN BUT FRONT DROPPING IN FROM THE NORTH MAY ALLOW
SURFACE HIGH TO THE WEST TO BUILD OVER THE WATERS LATE
SUN...RESULTING IN NORTH TO NORTHWEST FLOW DEVELOPING. CONFIDENCE
IN TIMING OF FRONTAL PASSAGE IS LOW AND SOUTHERLY FLOW COULD END
UP DOMINATING THE LONG TERM PERIOD. GRADIENT BECOMES PINCHED AHEAD
OF FRONT AND SPEEDS MAY INCREASE TO NEAR 20 KT LATER SAT. SEAS WILL
CONTINUE TO RUN 3 TO 5 FT BUT HEADLINE REQUIRING SEAS COULD EASILY
DEVELOP LATER SAT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...31
SHORT TERM...III
LONG TERM...III
AVIATION...HAWKINS
000
FXUS62 KRAH 060717
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
315 AM EDT WED MAY 6 2009
.SYNOPSIS...
A STATIONARY FRONT OVER CENTRAL NC WILL GRADUALLY WEAKEN AND
DISSIPATE TODAY. AN UPPER LEVEL TROUGH AND ATTENDANT SURFACE TROUGH
WILL PUSH EAST ACROSS CENTRAL NC LATE WEDNESDAY NIGHT THROUGH
THURSDAY MORNING...BRINING ANOTHER ROUND OF SHOWERS AND STORMS TO
NORTH CAROLINA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM WEDNESDAY...
MOST IMMINENT FORECAST CHALLENGE PERTAINS TO THE POSSIBILITY FOR
DENSE FOG THIS MORNING AS A NEARLY SATURATED AIRMASS ALONG A
STATIONARY FRONT ZONE ACROSS CENTRAL NC WILL MAKE FOR FAVORABLE
CONDITIONS. LATEST IR IMAGERY IS SHOWING SIGNIFICANT BREAKS IN MID
AND HIGH CLOUDS ACROSS THE AREA...WHICH COULD RESULT IN SOME
SUFFICIENT BL COOLING. A COUPLE OF REPORTING SITES ARE REPORTING
ONE HALF TO ONE QUARTER OF A MILE VISIBILITY RESTRICTIONS..
SO BEFORE IT IS ALL SAID AND DONE...MAY HAVE TO ISSUE A SHORT-FUSE
DENSE FOG ADVISORY FOR PORTIONS OF THE FORECAST AREA. WILL CONTINUE
TO MONITOR FOR THE NEXT COUPLE OF HOURS AND ISSUE AS NEEDED.
FOR THE REST OF TODAY AND TONIGHT...ANOTHER ROUND OF STORMS...OR
EVEN PERHAPS TWO...ARE EXPECTED THIS AFTERNOON AND OVERNIGHT AS THE
SFC BOUNDARY IS FORECAST TO WEAKEN AND LIFT NORTH THIS AFTERNOON IN
RESPONSE TO AN APPROACHING UPPER LEVEL TROUGH AND ATTENDANT SURFACE
TROUGH FROM THE WEST. MODELS HAVE TRENDED SLOWER AND SLIGHTLY
STRONGER WITH THE PASSAGE OF THE DIGGING UPPER WAVE...WITH IT NOW
FORECAST TO REMAIN WEST OF THE MTNS THROUGH 06Z THURSDAY...SWINGING
EAST ACROSS CENTRAL NC BETWEEN 12 TO 18Z.
THE FIRST ROUND OF CONVECTION LOOKS TO DEVELOP THIS
AFTERNOON...PRIMARILY DRIVEN BY DIFFERENTIAL HEATING AS THE BOUNDARY
WEAKENS AND LIFTS NORTH ACROSS THE AREA...WITH NO DISCERNIBLE
UPPER LEVEL SUPPORT...AS COMPARED TO PAST COUPLE OF DAYS. DEEP LAYER
SHEAR OF 30 TO 40 KTS WITH SBCAPE OF 800 TO 1200 JOULES FROM US 1
SOUTH AND EAST WILL SUPPORT A SLIGHT RISK OF SEVERE STORMS WITH THE
MAJOR THREAT BEING STRONG DAMAGING WINDS AND HAIL AS LARGE NICKEL TO
QUARTER SIZE HAIL AS WET-BULB ZEROS ARE FORECAST TO REMAIN PRETTY
HIGH...AOA 11.5KFT. A MUCH SMALLER...ISOLATED TORNADO THREAT COULD
EXIST AS WELL...IF THE FRONT MANAGES TO LINGER OR HOLD ON LONGER AS
THE NAM SUGGESTS...BETWEEN 18 TO 21Z (THE GFS LIFTS THE FRONT TO THE
NORTH FASTER THAN THE NAM). BUT THE GREATEST SEVERE THREAT AND HIGHER
POPS WILL ARRIVE IN THE EVENING AND OVERNIGHT HOURS WITH THE DIGGING
UPPER WAVE...WITH STRONG JET SUPPORT...BOTH ALOFT AND IN THE
LOW-LEVELS...ACCOMPANYING THE UPPER WAVE AS IT TRAVERSES WEST TO TO
EAST ACROSS THE REGION. CONCEPTUAL RECOGNITION WOULD SUGGEST A
LINEAR SQUALL LINE MOVING THROUGH THE AREA BETWEEN MIDNIGHT THROUGH
DAYBREAK THURSDAY MORNING...WITH VERTICAL SHEAR INCREASING TO 45 TO
50 KTS WITH MORE THAN ADEQUATE INSTABILITY AS MODELS SHOW 800 TO
1000 J/KG OF MUCAPE WITH 700 TO 500MB MID-LEVEL LAPSE RATES OF 7 TO
7.25 ACROSS THE AREA. ADDITIONALLY...ALTHOUGH THE FLOW IS MAINLY
UNIDIRECTIONAL...0 TO 1 KM HELICITY OF 250 TO 300 MS-1 MOVES THROUGH
THE AREA LATE WEDNESDAY NIGHT/THURSDAY MORNING AS SURFACE TROUGH
AND LOW-LEVEL JET MOVES THROUGH THE AREA. IF A SECONDARY MESO-LOW
DEVELOPS ALONG THE TROUGH...AN ISOLATED TORNADO COULD ACCOMPANY THE
THREAT OF STRAIGHT LINE WINDS AND HAIL.
TOUGH TEMPERATURE FORECAST FOR TODAY...DEPENDENT ON THE TIMING
OF THE DISSIPATION OF THE MORNING STRATUS...BUT SHOULD SEE A
SHARP TEMPERATURE GRADIENT ACROSS CENTRAL NC. WILL LEAN TOWARD THE
WARMER MAV GUIDANCE WITH BOUNDARY WEAKENING...AND THUS ALLOWING FOR
THE POTENTIAL TO SEE MORE BREAKS IN CLOUD COVER. HIGHS IN THE LOWER
TO MID 70S NW TO LOWER TO MID 80S SOUTHEAST. LOWS TONIGHT IN THE IN
THE MID TO UPPER 60S.
&&
.SHORT TERM /THURSDAY/...
AS OF 315 AM WEDNESDAY...
THE SLOWER TIMING OF THE PASSAGE OF THE UPPER TROUGH THURSDAY WILL
RESULT IN SCATTERED SHOWERS AND THUNDER EXTENDING WELL INTO THE
AFTERNOON...MAINLY ACROSS THE CENTRAL PIEDMONT AND COASTAL PLAIN
WITH SURFACE TROUGH AND 850-700 THETA-E RIDGE EXTENDING OVER THE
COASTAL PLAIN REGION. STRONG SURFACE HEATING WILL RESULT IN MARGINAL
TO MODEST INSTABILITY OF 1000 TO 1500 JOULES WITH COOLING
TEMPERATURES ALOFT BRINGING AN INCREASE THREAT OF HAIL AS WET-BULB
ZEROES FALL TO AROUND 9KFT ACROSS THE NORTHERN HALF. HIGHS AROUND 80
IN THE NW TO MID 80S SE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
AS OF 254 PM TUESDAY...
THURSDAY NIGHT SHOULD BE QUIET AS CONVECTIVE TRIGGERS APPEAR TO
BE ABSENT. A LIGHT SW FLOW SHOULD KEEP TEMPERATURES UP IN THE
LOWER TO MID 60S WITH PARTLY CLOUDY SKIES (A GOOD 10 DEGREES ABOVE
NORMAL).
FRIDAY THROUGH SATURDAY NIGHT... ALTHOUGH THE MEAN FLOW BECOMES
MORE ZONAL OR WESTERLY... MODELS SUGGEST THAT THERE SHOULD BE SOME
CONVECTIVE TRIGGERS TRAVERSING OUR AREA. A WEAK COLD FRONT IS
EXPECTED TO PUSH INTO THE NORTHERN SECTIONS OF NC FRIDAY... THEN
SLOWLY RETREAT AS A WARM FRONT SATURDAY. A STRONGER COLD FRONT IS
EXPECTED TO PUSH INTO NC FROM THE NW LATE SATURDAY. THERE SHOULD
BE ENOUGH MOISTURE AND INSTABILITY TO INCREASE THE POP INTO THE
CHANCE CATEGORY FOR FRIDAY THROUGH SATURDAY NIGHT AND EARLY
SUNDAY. THIS CONVECTIVE ACTIVITY SHOULD BE LARGELY DIURNALLY
DRIVEN EXCEPT FOR SATURDAY NIGHT WHEN THE COLD FRONT SHOULD
SUPPORT CONVERGENCE AND LIFT INTO THE OVERNIGHT PERIOD. LOWS WILL
CONTINUE TO AVERAGE WELL ABOVE NORMAL (IN THE 60S) FRIDAY THROUGH
SUNDAY. HIGHS WILL ALSO AVERAGE ABOVE NORMAL... MOSTLY IN THE
LOWER TO MID 80S THROUGH SUNDAY.
SUNDAY INTO MONDAY... THE COLD FRONT IS EXPECTED TO SHIFT SOUTH OF
NC SUNDAY AFTERNOON THROUGH MONDAY... AS A SURFACE HIGH IS
FORECAST TO SHIFT EAST ACROSS THE MID ATLANTIC AND NEW ENGLAND
STATES. POP SHOULD BE CONFINED TO AREAS TO OUR SOUTH NEAR THE
FRONT. THE LOW LEVEL FLOW SHOULD BECOME NE-E RATHER QUICKLY
LEADING TO POTENTIAL CLOUDINESS EARLY NEXT WEEK. IT WILL BE COOLER
BEHIND THE FRONT WITH LOWS IN THE 50S AND HIGHS IN THE 70S MONDAY
INTO TUESDAY (VERY CLOSE TO THE 30 YEAR NORMALS).
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 145 AM WEDNESDAY...
A NEARLY SATURATED AIRMASS...ASSOCIATED WITH A STALLED FRONT OVER
CENTRAL NC...WILL RESULT IN LIFR TO VFR CONDITIONS THIS MORNING.
THE IS THE POTENTIAL TO SEE SOME AREAS OF DENSE FOG (VISIBILITIES
ONE QUARTER MILE OR LESS)IF THE SIGNIFICANT BREAKS IN MID AND HIGH
CLOUDS CONTINUE AS INDICATED BY LATEST IR IMAGERY...BUT THE MOST
CRITICAL AVIATION IMPACTS WILL BE PRIMARILY DUE TO THE LOW LIFR
CEILINGS.
THE SREF SHOWS A SLOW BURN OFF OR LIFTING OF MORNING STRATUS/FOG
THIS MORNING...WITH VFR CEILINGS LINGERING THROUGH 15Z TO 16Z IN THE
VICINITY OF THE DISSIPATING FRONTAL ZONE ACROSS THE NORTHERN AND
CENTRAL PIEDMONT...WITH CEILINGS LIFTING TO VFR ACROSS THE SOUTH TO
MVFR ACROSS THE FAR NORTH. DIFFERENTIAL AFTERNOON HEATING WILL
LIKELY SUPPORT SCATTERED SHOWERS AND THUNDERSTORMS WITH CONVECTION
EXPECTED TO PERSIST WELL INTO THE NIGHT AS AN UPPER LEVEL
DISTURBANCE AND SURFACE TROUGH CROSSES THE REGION FROM WEST TO EAST
OVERNIGHT.
SHOWERS COULD LINGER INTO THE AFTERNOON ACROSS EASTERN NC AS SURFACE
TROUGH LINGERS ACROSS THE REGION. UNSETTLED WEATHER AND PERIODS OF
ADVERSE AVIATION CONDITIONS COULD RETURN AS EARLY AS
SATURDAY...PERSISTING INTO THE WEEKEND AS ANOTHER FRONT APPROACHES
FROM THE WEST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...CBL
SHORT TERM...CBL
LONG TERM...BADGETT
AVIATION...CBL
000
FXUS62 KRAH 060545
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
145 AM EDT WED MAY 6 2009
.SYNOPSIS...
A STATIONARY FRONT OVER CENTRAL NC WILL GRADUALLY WEAKEN AND
DISSIPATE TODAY. AN UPPER LEVEL TROUGH AND ATTENDANT SURFACE TROUGH
WILL PUSH EAST ACROSS CENTRAL NC LATE WEDNESDAY NIGHT THROUGH
THURSDAY MORNING...BRINING ANOTHER ROUND OF SHOWERS AND STORMS TO
NORTH CAROLINA.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 955 PM TUESDAY...
AIR MASS HAS STABILIZED WITH LOSS OF DAYTIME HEATING. SHORT TERM
CONCERN FOR TRAINING ECHOS IN SOUTHERN JOHNSTON AND NORTH WAYNE.
THESE WILL BE MONITORED FOR FLOOD POTENTIAL.
OTHER THAN THE ABOVE MENTIONED LINE...ONLY AN ISOLATED STROKE OF
LIGHTNING WITH STORMS EXITING INTO VIRGINIA AND NO THREAT
EXPECTED.
WITH UPPER LEVEL (250 MILLIBARS) LIFTING TO THE NORTHEAST AND LOSS
OF HEATING OF THE DAY... CONVECTIVE ACTIVITY SHOULD CONTINUE TO
DIMINISH OVERNIGHT. WILL NOWCAST CURRENT PRECIPITATION BUT
OTHERWISE RAIN CHANCES SLIGHT FOR THE REMAINDER OF THE NIGHT.
TEMPERATURES WILL SLIP NO MORE THAN A COUPLE OF DEGREES FROM
CURRENT READINGS. MID 50S NORTHWEST PIEDMONT TO MID 60S EAST AND
SOUTHEAST.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY/...
AS OF 254 PM TUESDAY...
MOIST AIR MASS WILL REMAIN IN PLACE WITH BEST INSTABILITY PROGGED TO
OCCUR EAST OF HIGHWAY 1. MODELS DIFFER ON TIMING OF NEXT MCV WITH
GFS/CANADIAN AS MUCH AS 6-9 HOURS FASTER THAN NAM-WRF. ECMWF A BIT
OF A COMPROMISE. CONSIDERING GFS USUALLY TOO FAST...FAVOR SLOWER
TIMING OFFERED BY NAM-WRF WITH SOME ADJUSTMENTS. EXPECT SCATTERED
CONVECTION TO FIRE DURING MAX HEATING WITH LITTLE IN THE MANNER OF
ORGANIZATION. EXPECT STORMS TO ORGANIZE INTO BROKEN SEGMENTS BY OR
AFTER 00Z AS MCV AND ASSOCIATED BULK SHEAR OF 35-40KTS BEGINS TO
AFFECT AREA. MAY SEE A FEW SEVERE STORMS AFTER SUNSET WITH MAIN
THREAT DAMAGING DOWNBURST AND LARGE HAIL. IF WASHED OUT BOUNDARY
MAINTAINS PRESENCE...SLIGHT TORNADIC POTENTIAL WILL EXIST. FAVOR
WARMER MOS GUIDANCE FOR MAX TEMPS WED AS SLY FLOW INCREASES AFTER
15Z. IF SUBSTANTIAL BREAKS DEVELOP...MAX TEMPS MAY END UP BEING 3
DEGREES WARMER.
MODELS GENERALLY AGREE IN THAT SHOWERS AND THUNDERSTORMS SHOULD BE
ONGOING WEDNESDAY EVENING OVER A GOOD PORTION OF OUR REGION. THIS
WILL BE IN RESPONSE TO THE MID/UPPER LEVEL TROUGH WHICH IS FORECAST
TO MOVE EAST ACROSS OUR REGION DURING THE EVENING AND OVERNIGHT
PERIODS. CONVECTION SHOULD SHIFT EASTWARD FROM THE PIEDMONT INTO
THE COASTAL PLAIN DURING THE LATE EVENING INTO THE OVERNIGHT
PERIOD... WITH THE PRE-FRONTAL TROUGH. THE ACTUAL COLD FRONT IS
EXPECTED TO SLOWLY REACH THE COASTAL PLAIN REGION BY AROUND 12Z
THURSDAY. MODELS GENERALLY AGREE ON A PROJECTED LULL IN THE
CONVECTIVE ACTIVITY ON THURSDAY. THIS WILL BE DUE TO SUBSIDENCE ON
THE BACK SIDE OF THE DEPARTING UPPER TROUGH SHOULD BE OVER OUR
REGION. QPF STORM TOTALS IN THE 0.50 TO 1.00 INCH RANGE ON
AVERAGE... WITH LOCALLY HIGHER TOTALS. LOWS WEDNESDAY NIGHT OF
60-65 EXPECTED... WITH THE WARMER MAV GUIDANCE PREFERRED SE.
HIGHS THURSDAY SHOULD RETURN TO THE 78 TO 85 RANGE NW TO SOUTH
WITH PARTLY SUNNY SKIES.
THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM WEDNESDAY
AFTERNOON INTO THE EVENING HOURS... AS A 35 TO 45KT SOUTH TO
SOUTHWESTERLY LOW LEVEL JET S-SW IS FORECAST TO BECOME ALIGNED OVER
CENTRAL AND EASTERN NC LATE WEDNESDAY INTO WEDNESDAY EVENING. THIS
SHOULD COMBINE WITH INCREASING INSTABILITY AND MODEST SHEAR TO
SUPPORT THE SEVERE THUNDERSTORM THREAT. THE ONE FACTOR THAT MAY
REDUCE THE SEVERE THREAT WILL BE THE TIMING OF THE COLD FRONT ACROSS
CENTRAL NC (MOSTLY DURING THE DIURNAL COOLING PERIOD OVERNIGHT DOWN
EAST). THE THREAT OF SEVERE SHOULD END BEFORE 12Z THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
AS OF 254 PM...
THURSDAY NIGHT SHOULD BE QUIET AS CONVECTIVE TRIGGERS APPEAR TO
BE ABSENT. A LIGHT SW FLOW SHOULD KEEP TEMPERATURES UP IN THE
LOWER TO MID 60S WITH PARTLY CLOUDY SKIES (A GOOD 10 DEGREES ABOVE
NORMAL).
FRIDAY THROUGH SATURDAY NIGHT... ALTHOUGH THE MEAN FLOW BECOMES
MORE ZONAL OR WESTERLY... MODELS SUGGEST THAT THERE SHOULD BE SOME
CONVECTIVE TRIGGERS TRAVERSING OUR AREA. A WEAK COLD FRONT IS
EXPECTED TO PUSH INTO THE NORTHERN SECTIONS OF NC FRIDAY... THEN
SLOWLY RETREAT AS A WARM FRONT SATURDAY. A STRONGER COLD FRONT IS
EXPECTED TO PUSH INTO NC FROM THE NW LATE SATURDAY. THERE SHOULD
BE ENOUGH MOISTURE AND INSTABILITY TO INCREASE THE POP INTO THE
CHANCE CATEGORY FOR FRIDAY THROUGH SATURDAY NIGHT AND EARLY
SUNDAY. THIS CONVECTIVE ACTIVITY SHOULD BE LARGELY DIURNALLY
DRIVEN EXCEPT FOR SATURDAY NIGHT WHEN THE COLD FRONT SHOULD
SUPPORT CONVERGENCE AND LIFT INTO THE OVERNIGHT PERIOD. LOWS WILL
CONTINUE TO AVERAGE WELL ABOVE NORMAL (IN THE 60S) FRIDAY THROUGH
SUNDAY. HIGHS WILL ALSO AVERAGE ABOVE NORMAL... MOSTLY IN THE
LOWER TO MID 80S THROUGH SUNDAY.
SUNDAY INTO MONDAY... THE COLD FRONT IS EXPECTED TO SHIFT SOUTH OF
NC SUNDAY AFTERNOON THROUGH MONDAY... AS A SURFACE HIGH IS
FORECAST TO SHIFT EAST ACROSS THE MID ATLANTIC AND NEW ENGLAND
STATES. POP SHOULD BE CONFINED TO AREAS TO OUR SOUTH NEAR THE
FRONT. THE LOW LEVEL FLOW SHOULD BECOME NE-E RATHER QUICKLY
LEADING TO POTENTIAL CLOUDINESS EARLY NEXT WEEK. IT WILL BE COOLER
BEHIND THE FRONT WITH LOWS IN THE 50S AND HIGHS IN THE 70S MONDAY
INTO TUESDAY (VERY CLOSE TO THE 30 YEAR NORMALS).
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 145 AM WEDNESDAY...
A NEARLY SATURATED AIRMASS...ASSOCIATED WITH A STALLED FRONT OVER
CENTRAL NC...WILL RESULT IN LIFR TO VFR CONDITIONS THIS MORNING.
THE IS THE POTENTIAL TO SEE SOME AREAS OF DENSE FOG (VISIBILITIES
ONE QUARTER MILE OR LESS)IF THE SIGNIFICANT BREAKS IN MID AND HIGH
CLOUDS CONTINUE AS INDICATED BY LATEST IR IMAGERY...BUT THE MOST
CRITICAL AVIATION IMPACTS WILL BE PRIMARILY DUE TO THE LOW LIFR
CEILINGS.
THE SREF SHOWS A SLOW BURN OFF OR LIFTING OF MORNING STRATUS/FOG
THIS MORNING...WITH VFR CEILINGS LINGERING THROUGH 15Z TO 16Z IN THE
VICINITY OF THE DISSIPATING FRONTAL ZONE ACROSS THE NORTHERN AND
CENTRAL PIEDMONT...WITH CEILINGS LIFTING TO VFR ACROSS THE SOUTH TO
MVFR ACROSS THE FAR NORTH. DIFFERENTIAL AFTERNOON HEATING WILL
LIKELY SUPPORT SCATTERED SHOWERS AND THUNDERSTORMS WITH CONVECTION
EXPECTED TO PERSIST WELL INTO THE NIGHT AS AN UPPER LEVEL
DISTURBANCE AND SURFACE TROUGH CROSSES THE REGION FROM WEST TO EAST
OVERNIGHT.
SHOWERS COULD LINGER INTO THE AFTERNOON ACROSS EASTERN NC AS SURFACE
TROUGH LINGERS ACROSS THE REGION. UNSETTLED WEATHER AND PERIODS OF
ADVERSE AVIATION CONDITIONS COULD RETURN AS EARLY AS
SATURDAY...PERSISTING INTO THE WEEKEND AS ANOTHER FRONT APPROACHES
FROM THE WEST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...RLH
SHORT TERM...BADGETT
LONG TERM...BADGETT
AVIATION...CBL
000
FXUS62 KILM 060529
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
129 AM EDT WED MAY 6 2009
.SYNOPSIS...
A STATIONARY FRONT EXTENDING FROM WEST TO EAST ACROSS CENTRAL NORTH
CAROLINA WILL HELP DEVELOP SHOWERS AND THUNDERSTORMS DURING THE NEXT
FEW DAYS AS WAVES OF LOW PRESSURE DEVELOP AND RIDE ALONG THIS
BOUNDARY. DRIER AIR WILL MAKE ITS WAY INTO THE REGION ON SATURDAY AS
HIGH PRESSURE STARTS TO BUILD INTO THE REGION FROM THE WEST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 9 PM TUESDAY...A NEARLY STATIONARY FRONT EXTENDS THROUGH THE
CHARLOTTE METRO AREA AND NORTHEAST THROUGH EASTERN NORTH CAROLINA.
EARLIER SEVERE CONVECTION ALONG THIS FRONT PRODUCED MULTIPLE
CONFIRMED TORNADOES. THIS OUTBREAK APPEARS TO HAVE BEEN PRODUCED BY
A NARROW EAST-WEST ORIENTED CORRIDOR ALONG AND SOUTH OF THE FRONT
WHERE TEMPERATURES WARMED INTO THE UPPER 70S...PRODUCING THE
REQUISITE INSTABILITY. SURFACE WINDS WERE BACKED THE VICINITY OF THE
FRONT WHICH ADDED THE HELICITY/SHEAR NEEDED. WHILE WINDS REMAIN
BACKED...INSTABILITY HAS WANED WITH THE LOSS OF DAYTIME HEATING...
AND AFTER COORDINATING WITH THE STORM PREDICTION CENTER WE HAVE
CANCELLED THE WATCH FOR OUR AREA OF NC/SC.
FOR THE REMAINDER OF THE OVERNIGHT PERIOD SKIES SHOULD REMAIN MOSTLY
CLOUDY WITH A LIGHT SOUTH WIND OUT AHEAD OF THE STATIONARY FRONT. A
MID-LEVEL SHORTWAVE TROUGH THAT HELPED PRODUCE THE EARLIER
STORMINESS IS NOW OFFSHORE AND A BROAD AREA OF SUBSIDENCE IN NOW
SPREADING OVERHEAD. ISOLATED SHOWERS...ESSENTIALLY PATCHES OF LIGHT
RAIN FROM MID-LEVEL CONVECTIVE DEBRIS CLOUDINESS...COULD PUSH ACROSS
THE AREA FROM TIME TO TIME BUT DRY WEATHER IS IN STORE FOR MOST
LOCATIONS. THE NEXT MID-LEVEL DISTURBANCE WILL NOT BEGIN TO AFFECT
THE AREA UNTIL AFTER SUNRISE WEDNESDAY.
LOW TEMPERATURES TONIGHT SHOULD REACH THE MID 60S MOST AREAS. THIS
IS ONLY A 3 DEGREE FALL FOR SOME INLAND AREAS WHERE THE COLD POOL
FROM EARLIER CONVECTION HAS SET UP SHOP. SOME LOWER 60S ARE POSSIBLE
ACROSS THE PEE DEE REGION...WITH SOME UPPER 60S NEAR THE COAST. THIS
IS ESSENTIALLY UNCHANGED FROM THE PREVIOUS FORECAST.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...RATHER UNSETTLED WEATHER THROUGH THE SHORT
TERM PERIOD AS SERIES OF SHORT WAVES MOVE THROUGH THE H5 FLOW.
WITH SFC BOUNDARY DRAPED ACROSS THE CWA DURING THIS PERIOD EXPECT
CONVECTION TO FIRE UP ACROSS THE CWA WITH THE GREATEST LIKELIHOOD
ACROSS THE CENTRAL AND WESTERN PORTIONS OF THE CWA DURING THIS
TIME FRAME. WILL DELINEATE THIS IN THE GRIDS WITH SLIGHT CHC POPS
ALONG THE COASTAL ZONES UP TO LIKELY TO THE WESTERN ZONES...SEA
BREEZE FRONT WILL STABILIZE THE AIR MASS ALONG THE COAST AS IT HAS
THE PAST FEW DAYS KEEPING THE SHOWERS AND STORMS INLAND UNTIL
LATER IN THE PERIOD WHEN THE FRONT DIPS FURTHER TO THE SOUTH AND
EAST AND SHORT WAVE ENERGY MOVES CLOSER TO THE COAST. HAVE
FOLLOWED THE GFS/MAV NUMBERS FOR THE PERIOD AND USED THE GFS FOR
POPS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 3 PM TUESDAY...FORECAST MODELS CONTINUE TO SHOW A FAST
WESTERLY FLOW THROUGH THE PERIOD. SHORTWAVES EMBEDDED IN THIS FLOW
WILL TRIGGER INCREASED CONVECTION...BUT TIMING OF THESE FEATURES IN
THE EXTENDED FORECAST PERIOD IS ALWAYS DIFFICULT. ONE SHORT WAVE MAY
AFFECT THE AREA FRIDAY AND ANOTHER LATER SATURDAY. THE PASSAGE OF
SECOND SHORT WAVE SHOULD BRING A COLD FRONT THROUGH THE AREA. THIS
FRONT SHOULD CLEAR OUR FORECAST AREA...BEFORE STALLING TO OUR S.
WILL CONTINUE PREVIOUS FORECAST TRENDS AND BRING DRIER AIR INTO THE
AREA LATE IN THE WEEKEND AND EARLY NEXT WEEK. THE DRIER AIR WILL BE
ACCOMPANIED BY COOLER TEMPS...EVEN WITH FULL SUNSHINE...AS HIGH
PRESSURE OF CANADIAN ORIGIN BUILDS SOUTH.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AT 05 UTC...THE STATIONARY FRONT CONTINUES TO RUN FROM COASTAL
VIRGINA AND NORTH CAROLINA BORDER TO JUST SOUTH OF CHARLOTTE. THIS
FRONT WILL REMAIN TO THE NORTHWEST OF ALL TAF SITE THROUGH THIS
PERIOD. CONTINUED SHORT WAVES ARE EXPECTED TO RIPPLE ALONG THE FRONT
AND IF INSTABILITY CAN REBOUND OVER THE AREA THUNDERSTORMS WILL
AGAIN DEVELOP ESPECIALLY AFTERNOON WEDNESDAY.
EXPECT POSSIBLE IFR CEILINGS TO DEVELOP WITH WINDS JUST ABOVE THE
BOUNDARY LAYER AND ABUNDANT MOISTURE AFTER 08 UTC...ALSO MVFR
CONDITIONS ARE EXPECTED TO REDEVELOP FOR VSBY AT KLBT AND KFLO.
EXTENDED OUTLOOK THROUGH SUNDAY...SCATTERED AFTERNOON AND EVENING
THUNDERSTORMS EACH AFTERNOON.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 9 PM TUESDAY...SOUTH WINDS ARE AVERAGING 15 KT THIS EVENING
WITH SEAS 3 FT NEARSHORE TO 4 FT AWAY FROM SHORE. THIS IS SLIGHTLY
LOWER ON SEAS THAN EARLIER FORECAST...BUT REFLECTS THE TREND OVER
THE PAST TWO TO THREE DAYS WHERE THE NOAA WAVEWATCH MODEL HAS BEEN
CONSISTENTLY OVERFORECASTING SEAS. DESPITE STEADILY WARMING SEA
SURFACE TEMPERATURES THIS WEEK...AIR TEMPERATURES HAVE WARMED JUST
AS FAST AND ARE MAINTAINING A STABLE MIXING PROFILE IN THE MARINE
BOUNDARY LAYER. SHOWER/T-STORM ACTIVITY SHOULD REMAIN GENERALLY
INLAND FROM THE COASTAL WATERS TONIGHT...BUT A FEW SHOWERS MAY DRIFT
OFFSHORE AFTER MIDNIGHT...ESPECIALLY ALONG THE SOUTH CAROLINA COAST.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...WINDS TO PREVAIL OUT OF THE FOR WEDNESDAY
BECOMING SW ON THURSDAY AT 10 TO 15 KTS AND AROUND 20 KTS FROM 20-40
NM OUT. SEAS WILL BE RUNNING IN THE 3-5 FOOT RANGE NEAR SHORE AND
APPROACH THE 6 FOOT CRITERIA FOR SCA ON THURSDAY OVER ONSLOW BAY
BEFORE THE SEAS START TO SUBSIDE BY THURSDAY EVENING.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 3 PM TUESDAY...WIND DIRECTION WILL REMAIN S TO SW UNTIL COLD
FRONTAL PASSAGE WHICH MAY OCCUR SAT NIGHT/SUN MORNING. ONGOING
SMALL CRAFT ADVISORY CONDITIONS AT BEGINNING OF PERIOD MAY PERSIST
FOR MUCH OF THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAC
NEAR TERM...TRA
SHORT TERM...MAC
LONG TERM...RJD
AVIATION...HAWKINS
000
FXUS62 KMHX 060228
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
1028 PM EDT TUE MAY 5 2009
.SYNOPSIS...
FRONT NORTH AND WEST OF THE AREA...AND WILL REMAIN THERE OVER THE
NEXT FEW DAYS. FRONT WILL DISSIPATE FRIDAY AS ANOTHER FRONT
APPROACHES FROM THE WEST. THIS FRONT WILL BE OVER THE AREA SATURDAY
AND PASS EAST OF THE AREA SATURDAY NIGHT. HIGH PRESSURE OVER AREA
SUNDAY
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 715 PM TUE...QUICK UPDATE TO LOWER POPS SIGNIF THIS EVENING
ESPCLY CST AS ALL ACTIVITY IS WELL TO THE NW NEAR BNDRY. DECENT INSTAB
PERSISTS OVER THE INLAND AREAS AND AS WAVE OF LOW PRES MOVES NE ALONG
BNDRY COULD SEE SOME REDEVELOPMENT LATER ESPCLY INLAND CLOSER TO THE
BNDRY. DECENT SHEAR COMBINED WITH INSTAB COULD LEAD TO SOME SEVERE
THIS EVENING HOWEVER WITH SUN GOING DOWN SEVERE THREAT WILL SLOWLY
DIMINISH. NO CHANGE TO LOW TEMPS WITH MID TO UPR 60S MOST AREAS.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
BRIEF LULL WED AM IN PCPN WI LWR POPS AS FRNT CONTS TO LIFT N AND
AHD OF NXT APPCHG SYS. A WRM FRNT AHD OF NXT SYS WL SLIDE INTO CWA
WED AM AS ASSCTFD SFC LO STAY TO THE W. 5H TROF BOTTOMS OUT WED OVR
THE MID W. LOT OF UPR LVL ENERGY OVR AREA SO WL RMN UNSETTLED THRU
THE RMNDR OF THE WORK WK. HI TEMPS IN THE LWR 80S WED...RISING TO
THE MID 80S BY FRI WI SW LO LVL FLO.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
MSTLY ZNL FLO OVR AREA DURING THE XTNDD PD AS MOST OF THE ENERGY
STAYS TO THE N OF NC. WK PIECES OF ENERGY WL MV THRU THE FLO FROM TM
TO TM. A FRNT WL DROP THRU AREA SAT NGT. THEN A SYS WL MV UP FRM THE
SRN STRM ON TUE. UNCERTAINTY ON TIMING AND STRNGTH SO WL KP CHC POPS
IN THRU THE PD. TEMPS IN THE UPR 80S THRU THE WKEND...WL COOL TO UPR
70S OR LWR 80S AS FRNT GOES THRU SUN.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
AS OF 10 PM...MVFR CIGS HAVE DEVELOPED OVER EASTERN TERMINALS
THIS EVENING WHILE WESTERN TERMINALS REMAIN VFR. SOME SHRA
POSSIBLE OVER THE WESTERN TERMINALS THIS EVENING AS CONVECTION
DIMINISHES JUST WEST OF THE AREA OTHERWISE EXPECT MVFR CIGS TO
DEVELOP AND LOWER TO IFR ALL TERMINALS OVERNIGHT. SOME FOG IS
ALSO POSSIBLE LATE TONIGHT BUT WINDS WILL NOT DECOUPLE SO VSBYS
NOT EXPECTED TO DROP BELOW MVFR.
LOOK FOR ANOTHER ROUND OF CONVECTION WED WITH VERY LITTLE OVERALL
CHANGE IN AIRMASS UNTIL LATE WEEKEND WHEN A FRONT PUSHES THROUGH
THE REGION.
&&
.MARINE...
AS OF 10 PM...MADE MINOR TWEAKS TO WINDS THIS UPDATE OTHERWISE
LITTLE CHANGE TO CURRENT FORECAST. SEAS NOW 6 FT AT DIAMOND BUOY
AND WW3 GUIDANCE CONTINUES TO INDICATE 6 FT SEAS DEVELOPING OVER
EASTERN PORTIONS OF THE CENTRAL/SOUTHERN WATERS OVERNIGHT AS
PERSISTENT SW WINDS CONTINUE. SCA NOW IN EFFECT ACROSS THESE
WATERS OVERNIGHT INTO WEDNESDAY. BY THU THE UPPER TROF PUSHES INTO
THE SE...AND THE SFC FRONT SAGS S AS WELL. UNFORTUNATELY IT WASHES
OUT AND WE CONTINUE IN A SW FLOW INTO SAT. BY SUNDAY THE UPPER
TROF IS REINFORCED...A SFC HIGH SLIDES OUT OF CANADA...AND A COLD
FRONT FINALLY PUSHES THROUGH THE REGION. OVERALL NO NOTABLE SWELLS
OUTSIDE OF THE BUILDING SW...SO SEAS WILL LIKELY SUBSIDE QUICKLY
WITH A WIND SHIFT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THURSDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT THURSDAY FOR AMZ156.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT WEDNESDAY FOR AMZ158.
&&
$$
SYNOPSIS...CGG
NEAR TERM...RF
SHORT TERM...CGG
LONG TERM...CGG
AVIATION...SJ/JW
MARINE...SJ/JW
000
FXUS62 KRAH 060206
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1006 PM EDT TUE MAY 5 2009
.SYNOPSIS...
A WEAK STATIONARY FRONT OVER CENTRAL NC WILL PUSH NORTH AS A WARM
FRONT LATER TONIGHT. AN UPPER LEVEL TROUGH AND SURFACE COLD FRONT
ARE EXPECTED TO PUSH EAST ACROSS CENTRAL NC WEDNESDAY NIGHT INTO
THURSDAY MORNING.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 955 PM...
AIR MASS HAS STABILIZED WITH LOSS OF DAYTIME HEATING. SHORT TERM
CONCERN FOR TRAINING ECHOS IN SOUTHERN JOHNSTON AND NORTH WAYNE.
THESE WILL BE MONITORED FOR FLOOD POTENTIAL.
OTHER THAN THE ABOVE MENTIONED LINE...ONLY AN ISOLATED STROKE OF
LIGHTNING WITH STORMS EXITING INTO VIRGINIA AND NO THREAT
EXPECTED.
WITH UPPER LEVEL (250 MILLIBARS) LIFTING TO THE NORTHEAST AND LOSS
OF HEATING OF THE DAY... CONVECTIVE ACTIVITY SHOULD CONTINUE TO
DIMINISH OVERNIGHT. WILL NOWCAST CURRENT PRECIPITATION BUT
OTHERWISE RAIN CHANCES SLIGHT FOR THE REMAINDER OF THE NIGHT.
TEMPERATURES WILL SLIP NO MORE THAN A COUPLE OF DEGREES FROM
CURRENT READINGS. MID 50S NORTHWEST PIEDMONT TO MID 60S EAST AND
SOUTHEAST.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY/...
AS OF 254 PM TUESDAY...
MOIST AIR MASS WILL REMAIN IN PLACE WITH BEST INSTABILITY PROGGED TO
OCCUR EAST OF HIGHWAY 1. MODELS DIFFER ON TIMING OF NEXT MCV WITH
GFS/CANADIAN AS MUCH AS 6-9 HOURS FASTER THAN NAM-WRF. ECMWF A BIT
OF A COMPROMISE. CONSIDERING GFS USUALLY TOO FAST...FAVOR SLOWER
TIMING OFFERED BY NAM-WRF WITH SOME ADJUSTMENTS. EXPECT SCATTERED
CONVECTION TO FIRE DURING MAX HEATING WITH LITTLE IN THE MANNER OF
ORGANIZATION. EXPECT STORMS TO ORGANIZE INTO BROKEN SEGMENTS BY OR
AFTER 00Z AS MCV AND ASSOCIATED BULK SHEAR OF 35-40KTS BEGINS TO
AFFECT AREA. MAY SEE A FEW SEVERE STORMS AFTER SUNSET WITH MAIN
THREAT DAMAGING DOWNBURST AND LARGE HAIL. IF WASHED OUT BOUNDARY
MAINTAINS PRESENCE...SLIGHT TORNADIC POTENTIAL WILL EXIST. FAVOR
WARMER MOS GUIDANCE FOR MAX TEMPS WED AS SLY FLOW INCREASES AFTER
15Z. IF SUBSTANTIAL BREAKS DEVELOP...MAX TEMPS MAY END UP BEING 3
DEGREES WARMER.
MODELS GENERALLY AGREE IN THAT SHOWERS AND THUNDERSTORMS SHOULD BE
ONGOING WEDNESDAY EVENING OVER A GOOD PORTION OF OUR REGION. THIS
WILL BE IN RESPONSE TO THE MID/UPPER LEVEL TROUGH WHICH IS FORECAST
TO MOVE EAST ACROSS OUR REGION DURING THE EVENING AND OVERNIGHT
PERIODS. CONVECTION SHOULD SHIFT EASTWARD FROM THE PIEDMONT INTO
THE COASTAL PLAIN DURING THE LATE EVENING INTO THE OVERNIGHT
PERIOD... WITH THE PRE-FRONTAL TROUGH. THE ACTUAL COLD FRONT IS
EXPECTED TO SLOWLY REACH THE COASTAL PLAIN REGION BY AROUND 12Z
THURSDAY. MODELS GENERALLY AGREE ON A PROJECTED LULL IN THE
CONVECTIVE ACTIVITY ON THURSDAY. THIS WILL BE DUE TO SUBSIDENCE ON
THE BACK SIDE OF THE DEPARTING UPPER TROUGH SHOULD BE OVER OUR
REGION. QPF STORM TOTALS IN THE 0.50 TO 1.00 INCH RANGE ON
AVERAGE... WITH LOCALLY HIGHER TOTALS. LOWS WEDNESDAY NIGHT OF
60-65 EXPECTED... WITH THE WARMER MAV GUIDANCE PREFERRED SE.
HIGHS THURSDAY SHOULD RETURN TO THE 78 TO 85 RANGE NW TO SOUTH
WITH PARTLY SUNNY SKIES.
THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM WEDNESDAY
AFTERNOON INTO THE EVENING HOURS... AS A 35 TO 45KT SOUTH TO
SOUTHWESTERLY LOW LEVEL JET S-SW IS FORECAST TO BECOME ALIGNED OVER
CENTRAL AND EASTERN NC LATE WEDNESDAY INTO WEDNESDAY EVENING. THIS
SHOULD COMBINE WITH INCREASING INSTABILITY AND MODEST SHEAR TO
SUPPORT THE SEVERE THUNDERSTORM THREAT. THE ONE FACTOR THAT MAY
REDUCE THE SEVERE THREAT WILL BE THE TIMING OF THE COLD FRONT ACROSS
CENTRAL NC (MOSTLY DURING THE DIURNAL COOLING PERIOD OVERNIGHT DOWN
EAST). THE THREAT OF SEVERE SHOULD END BEFORE 12Z THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
AS OF 254 PM...
THURSDAY NIGHT SHOULD BE QUIET AS CONVECTIVE TRIGGERS APPEAR TO
BE ABSENT. A LIGHT SW FLOW SHOULD KEEP TEMPERATURES UP IN THE
LOWER TO MID 60S WITH PARTLY CLOUDY SKIES (A GOOD 10 DEGREES ABOVE
NORMAL).
FRIDAY THROUGH SATURDAY NIGHT... ALTHOUGH THE MEAN FLOW BECOMES
MORE ZONAL OR WESTERLY... MODELS SUGGEST THAT THERE SHOULD BE SOME
CONVECTIVE TRIGGERS TRAVERSING OUR AREA. A WEAK COLD FRONT IS
EXPECTED TO PUSH INTO THE NORTHERN SECTIONS OF NC FRIDAY... THEN
SLOWLY RETREAT AS A WARM FRONT SATURDAY. A STRONGER COLD FRONT IS
EXPECTED TO PUSH INTO NC FROM THE NW LATE SATURDAY. THERE SHOULD
BE ENOUGH MOISTURE AND INSTABILITY TO INCREASE THE POP INTO THE
CHANCE CATEGORY FOR FRIDAY THROUGH SATURDAY NIGHT AND EARLY
SUNDAY. THIS CONVECTIVE ACTIVITY SHOULD BE LARGELY DIURNALLY
DRIVEN EXCEPT FOR SATURDAY NIGHT WHEN THE COLD FRONT SHOULD
SUPPORT CONVERGENCE AND LIFT INTO THE OVERNIGHT PERIOD. LOWS WILL
CONTINUE TO AVERAGE WELL ABOVE NORMAL (IN THE 60S) FRIDAY THROUGH
SUNDAY. HIGHS WILL ALSO AVERAGE ABOVE NORMAL... MOSTLY IN THE
LOWER TO MID 80S THROUGH SUNDAY.
SUNDAY INTO MONDAY... THE COLD FRONT IS EXPECTED TO SHIFT SOUTH OF
NC SUNDAY AFTERNOON THROUGH MONDAY... AS A SURFACE HIGH IS
FORECAST TO SHIFT EAST ACROSS THE MID ATLANTIC AND NEW ENGLAND
STATES. POP SHOULD BE CONFINED TO AREAS TO OUR SOUTH NEAR THE
FRONT. THE LOW LEVEL FLOW SHOULD BECOME NE-E RATHER QUICKLY
LEADING TO POTENTIAL CLOUDINESS EARLY NEXT WEEK. IT WILL BE COOLER
BEHIND THE FRONT WITH LOWS IN THE 50S AND HIGHS IN THE 70S MONDAY
INTO TUESDAY (VERY CLOSE TO THE 30 YEAR NORMALS).
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
AS OF 737 PM TUESDAY...
SCATTERED CONVECTION OVER REGION WILL BECOME ISOLATED BY 03Z AS AIR
MASS STABILIZES.
IFR/LIFR CEILINGS EARLY THIS EVENING OVER THE NORTHERN PIEDMONT WILL
LIKELY PERSIST THROUGH THE OVERNIGHT. WILL LIKELY SEE IFR OR LIFR
VISIBILITY OVER THE NORTHERN PIEDMONT AS RESIDUAL COOL POOL NEAR
SURFACE WILL SATURATE...RESULTING IN THE DEVELOPMENT OF
FOG...POSSIBLY DENSE FOG. VFR CEILINGS OVER THE REST OF CENTRAL NC
WILL LOWER TO MVFR CATEGORY AS CLOUD BASES BETWEEN BETWEEN 1500-2500
FT OCCUR.
EXPECT A LULL IN THE CONVECTION OVERNIGHT THROUGH EARLY WEDNESDAY
MORNING. NEARLY SATURATED AIR MASS WILL RESULT IN LIFR CEILINGS AND
POSSIBLY LIFR VISIBILITIES EARLY IN THE MORNING. FOG AND LOW
STRATUS THAT FORM WILL LIFT BETWEEN 13-15Z WED.
WEDNESDAY...A MOIST AND MARGINALLY UNSTABLE AIR MASS WILL RESULT IN
BROKEN CEILINGS BETWEEN 2000-3500 FT BY AFTERNOON. A S-SW WIND
SUSTAINED 8-12 KTS WITH GUSTS 19-23KTS EXPECTED...ESPECIALLY IN
VICINITY OF KFAY AND KRWI WHERE HEATING MAY BE A BIT STRONGER. AIR
MASS WILL AGAIN SUPPORT SCATTERED TO NUMEROUS SHOWERS AND SCATTERED
THUNDERSTORMS ...MAINLY AFTER 16Z. EXPECT CONVECTION TO PERSIST WELL
INTO THE NIGHT AS AN UPPER LEVEL DISTURBANCE APPROACHES AND CROSSES
THE REGION AFTER 00Z.
STABLE CONDITIONS EXPECTED THU INTO THU NIGHT WHILE A RETURN TO
UNSTABLE CONDITIONS AND PERIODS OF ADVERSE AVIATION CONDITIONS
ANTICIPATED FOR FRIDAY INTO SATURDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BADGETT
LONG TERM...BADGETT
AVIATION...WSS
000
FXUS62 KILM 060156
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
956 PM EDT TUE MAY 5 2009
.SYNOPSIS...
A STATIONARY FRONT EXTENDING FROM WEST TO EAST ACROSS CENTRAL NORTH
CAROLINA WILL HELP DEVELOP SHOWERS AND THUNDERSTORMS DURING THE NEXT
FEW DAYS AS WEAK WAVES OF LOW PRESSURE DEVELOP AND RIDE ALONG THIS
BOUNDARY. DRIER AIR WILL MAKE ITS WAY INTO THE REGION ON SATURDAY AS
HIGH PRESSURE STARTS TO BUILD INTO THE REGION FROM THE WEST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 9 PM TUESDAY...A NEARLY STATIONARY FRONT EXTENDS THROUGH THE
CHARLOTTE METRO AREA AND NORTHEAST THROUGH EASTERN NORTH CAROLINA.
EARLIER SEVERE CONVECTION ALONG THIS FRONT PRODUCED MULTIPLE
CONFIRMED TORNADOES. THIS OUTBREAK APPEARS TO HAVE BEEN PRODUCED BY
A NARROW EAST-WEST ORIENTED CORRIDOR ALONG AND SOUTH OF THE FRONT
WHERE TEMPERATURES WARMED INTO THE UPPER 70S...PRODUCING THE
REQUISITE INSTABILITY. SURFACE WINDS WERE BACKED THE VICINITY OF THE
FRONT WHICH ADDED THE HELICITY/SHEAR NEEDED. WHILE WINDS REMAIN
BACKED...INSTABILITY HAS WANED WITH THE LOSS OF DAYTIME HEATING...
AND AFTER COORDINATING WITH THE STORM PREDICTION CENTER WE HAVE
CANCELLED THE WATCH FOR OUR AREA OF NC/SC.
FOR THE REMAINDER OF THE OVERNIGHT PERIOD SKIES SHOULD REMAIN MOSTLY
CLOUDY WITH A LIGHT SOUTH WIND OUT AHEAD OF THE STATIONARY FRONT. A
MID-LEVEL SHORTWAVE TROUGH THAT HELPED PRODUCE THE EARLIER
STORMINESS IS NOW OFFSHORE AND A BROAD AREA OF SUBSIDENCE IN NOW
SPREADING OVERHEAD. ISOLATED SHOWERS...ESSENTIALLY PATCHES OF LIGHT
RAIN FROM MID-LEVEL CONVECTIVE DEBRIS CLOUDINESS...COULD PUSH ACROSS
THE AREA FROM TIME TO TIME BUT DRY WEATHER IS IN STORE FOR MOST
LOCATIONS. THE NEXT MID-LEVEL DISTURBANCE WILL NOT BEGIN TO AFFECT
THE AREA UNTIL AFTER SUNRISE WEDNESDAY.
LOW TEMPERATURES TONIGHT SHOULD REACH THE MID 60S MOST AREAS. THIS
IS ONLY A 3 DEGREE FALL FOR SOME INLAND AREAS WHERE THE COLD POOL
FROM EARLIER CONVECTION HAS SET UP SHOP. SOME LOWER 60S ARE POSSIBLE
ACROSS THE PEE DEE REGION...WITH SOME UPPER 60S NEAR THE COAST. THIS
IS ESSENTIALLY UNCHANGED FROM THE PREVIOUS FORECAST.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...RATHER UNSETTLED WEATHER THROUGH THE SHORT
TERM PERIOD AS SERIES OF SHORT WAVES MOVE THROUGH THE H5 FLOW.
WITH SFC BOUNDARY DRAPED ACROSS THE CWA DURING THIS PERIOD EXPECT
CONVECTION TO FIRE UP ACROSS THE CWA WITH THE GREATEST LIKELIHOOD
ACROSS THE CENTRAL AND WESTERN PORTIONS OF THE CWA DURING THIS
TIME FRAME. WILL DELINEATE THIS IN THE GRIDS WITH SLIGHT CHC POPS
ALONG THE COASTAL ZONES UP TO LIKELY TO THE WESTERN ZONES...SEA
BREEZE FRONT WILL STABILIZE THE AIR MASS ALONG THE COAST AS IT HAS
THE PAST FEW DAYS KEEPING THE SHOWERS AND STORMS INLAND UNTIL
LATER IN THE PERIOD WHEN THE FRONT DIPS FURTHER TO THE SOUTH AND
EAST AND SHORT WAVE ENERGY MOVES CLOSER TO THE COAST. HAVE
FOLLOWED THE GFS/MAV NUMBERS FOR THE PERIOD AND USED THE GFS FOR
POPS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 3 PM TUESDAY...FORECAST MODELS CONTINUE TO SHOW A FAST
WESTERLY FLOW THROUGH THE PERIOD. SHORTWAVES EMBEDDED IN THIS FLOW
WILL TRIGGER INCREASED CONVECTION...BUT TIMING OF THESE FEATURES IN
THE EXTENDED FORECAST PERIOD IS ALWAYS DIFFICULT. ONE SHORT WAVE MAY
AFFECT THE AREA FRIDAY AND ANOTHER LATER SATURDAY. THE PASSAGE OF
SECOND SHORT WAVE SHOULD BRING A COLD FRONT THROUGH THE AREA. THIS
FRONT SHOULD CLEAR OUR FORECAST AREA...BEFORE STALLING TO OUR S.
WILL CONTINUE PREVIOUS FORECAST TRENDS AND BRING DRIER AIR INTO THE
AREA LATE IN THE WEEKEND AND EARLY NEXT WEEK. THE DRIER AIR WILL BE
ACCOMPANIED BY COOLER TEMPS...EVEN WITH FULL SUNSHINE...AS HIGH
PRESSURE OF CANADIAN ORIGIN BUILDS SOUTH.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
AT 00 UTC...THE STATIONARY FRONT CONTINUES TO RUN FROM JUST SOUTH OF
NORFOLK TO CHARLOTTE. THE CLOUD COVER AND LACK OF INSTABILITY FROM
MORNING CONVECTION HAS REDUCED THE CHANCES FOR THUNDERSTORMS AT THE
TERMINAL SITES THIS EVENING. HAVE KEPT MOST TAF SITES AT VFR/MVFR
FOR THE REMAINDER OF THE OVERNIGHT. WITH STRONG WINDS ALONG THE
COAST THERE IS A POSSIBILITY FOR STRATUS TO FORM AT THE COASTAL
SITES AND WITH LIGHTER WINDS AND SOME CLOUD COVER MAY SEE SOME MIST
TO 3 MILES.
WITH DISTURBANCES IN THE WEST TO SOUTHWESTERLY FLOW AND FRONTAL
BOUNDARY JUST TO THE NORTH OF THE TAF SITES THERE IS A GOOD CHANCE
FOR CONVECTION IN THE AFTERNOON HOURS OF WEDNESDAY.
EXTENDED OUTLOOK THROUGH SUNDAY...SCATTERED AFTERNOON AND EVENING
THUNDERSTORMS EACH AFTERNOON.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 9 PM TUESDAY...SOUTH WINDS ARE AVERAGING 15 KT THIS EVENING
WITH SEAS 3 FT NEARSHORE TO 4 FT AWAY FROM SHORE. THIS IS SLIGHTLY
LOWER ON SEAS THAN EARLIER FORECAST...BUT REFLECTS THE TREND OVER
THE PAST TWO TO THREE DAYS WHERE THE NOAA WAVEWATCH MODEL HAS BEEN
CONSISTENTLY OVERFORECASTING SEAS. DESPITE STEADILY WARMING SEA
SURFACE TEMPERATURES THIS WEEK...AIR TEMPERATURES HAVE WARMED JUST
AS FAST AND ARE MAINTAINING A STABLE MIXING PROFILE IN THE MARINE
BOUNDARY LAYER. SHOWER/T-STORM ACTIVITY SHOULD REMAIN GENERALLY
INLAND FROM THE COASTAL WATERS TONIGHT...BUT A FEW SHOWERS MAY DRIFT
OFFSHORE AFTER MIDNIGHT...ESPECIALLY ALONG THE SOUTH CAROLINA COAST.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...WINDS TO PREVAIL OUT OF THE FOR WEDNESDAY
BECOMING SW ON THURSDAY AT 10 TO 15 KTS AND AROUND 20 KTS FROM 20-40
NM OUT. SEAS WILL BE RUNNING IN THE 3-5 FOOT RANGE NEAR SHORE AND
APPROACH THE 6 FOOT CRITERIA FOR SCA ON THURSDAY OVER ONSLOW BAY
BEFORE THE SEAS START TO SUBSIDE BY THURSDAY EVENING.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 3 PM TUESDAY...WIND DIRECTION WILL REMAIN S TO SW UNTIL COLD
FRONTAL PASSAGE WHICH MAY OCCUR SAT NIGHT/SUN MORNING. ONGOING
SMALL CRAFT ADVISORY CONDITIONS AT BEGINNING OF PERIOD MAY PERSIST
FOR MUCH OF THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAC
NEAR TERM...TRA
SHORT TERM...MAC
LONG TERM...RJD
AVIATION...HAWKINS
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