[top]
000
FXUS62 KILM 200241
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
955 PM EDT FRI SEP 19 2008
.SYNOPSIS...
HIGH PRESSURE ACROSS THE NORTHEAST WILL RIDGE INTO THE CAROLINAS
THROUGH THE WEEKEND...AND INTO NEXT WEEK. THE FORECAST AREA CAN
EXPECT COOLER THAN NORMAL TEMPERATURES AND LITTLE IF ANY RAINFALL.
LOW PRESSURE SITUATED ALONG A STALLED BOUNDARY OFFSHORE FROM THE
CAROLINAS...WILL MOVE NORTHEAST...AWAY FROM THE AREA BY EARLY
SUNDAY. THIS WILL KEEP A FRISKY NORTH TO NORTHEAST WIND ACROSS THE
AREA..ESPECIALLY OVER THE COASTAL WATERS. A TROUGH OF LOW PRESSURE
IS EXPECTED TO DEVELOP OFFSHORE FROM THE SOUTHEAST U.S. COAST-LINE
MONDAY...AND PERSIST THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 9 PM FRIDAY...STALLED FRONTAL BOUNDARY WELL OFFSHORE THAT
EXTENDS NE-SW AND PARALLELLING THE U.S. COASTLINE...WILL HAVE AN
AREA OF LOW PRESSURE MOVE NE ALONG IT OVERNITE...REACHING THE CAPE
LOOKOUT LATITUDE BY SUNRISE SATURDAY. HAVE BECOME MORE OPTIMISTIC
WITH CLOUD POTENTIAL ACROSS THE FORECAST AREA...BASED ON LATEST
CLOUD TRENDS VIA 11-3.9 MICRON CHANNEL AND WHAT TRANSPIRED THE
PREVIOUS NITE. DONT EXPECT OPAQUE CI/CS FROM THE WEST OR AT MOST
FEW/SCT STRATO CU FROM THE NORTHEAST OR OFF THE ADJACENT ATL WATERS.
00Z MHX IS ONLY SLITELY MORE MOIST IN THE LOWER LEVELS WITH PWS
STILL BELOW 1 INCH. AS FOR TEMPS...HAVE TWEAKED MAYBE 1 TO 2 DEGREES
LOWER...MAINLY INLAND LOCATIONS. BOUNDARY CONTINUES TO REMAIN MIXED
AND DONT EXPECT ANY SUPER SFC BASED INVERSION WITH WINDS DECOUPLING.
HOWEVER...1 DIFFERENCE FROM LAST NITE ARE THAT SFC DEWPOINTS ARE
RUNNING SLITELY LOWER ESPECIALLY ACROSS THE ILM INLAND LOCATIONS.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...DURING SATURDAY THE FORECAST AREA WILL BE
BETWEEN MID/UPPER RIDGE FAR OFF THE SOUTHEAST UNITED STATES COAST
AND TROUGH ACROSS THE MS VALLEY. AT THE SURFACE...A WEAK AREA OF LOW
PRESSURE OR WAVE ALONG THE OLD FRONT WILL ATTEMPT TO DRIFT TOWARD
THE OUTER BANKS BEFORE SLOWLY LIFTING AWAY. ALTHOUGH H85-H5 LAYER RH
IS NOT THAT IMPRESSIVE TRAJECTORIES IN THE 925MB LEVEL ARE
SUPPORTIVE OF MOISTURE ADVECTION INTO THE FORECAST AREA. IN FACT
THERE IS A SURGE IN LOW-LEVEL THETA-E BY SATURDAY WHICH IS MOST
LIKELY REFLECTIVE OF SLIGHTLY DEEPER MOISTURE TRYING TO ADVECT INTO
THE AREA. NOT ENTIRELY SOLD ON SIGNIFICANT AREAL COVERAGE OF SHOWERS
DURING THIS EVENT...WOULD GO HIGHER IF THE TREND WAS FOR A FARTHER
WESTWARD DRIFT IN THE LOW/WAVE. FOR NOW...WILL STICK WITH SLIGHT
CHANCE POPS...PRIMARILY FOR THE COASTAL COUNTIES. GIVEN THE FLOW
REGIME FAVOR A BLEND TOWARD THE COOLEST OF THE GUIDANCE THROUGH THE
PERIOD.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3 PM FRIDAY...HIGH PRESSURE CONTINUES TO NOSE DOWN INTO LOCAL
AREA FROM THE NORTH...WITH CENTER OF SFC HIGH IN THE VICINITY OF NEW
ENGLAND. WED INTO FRI THE CENTER OF THE HIGH SHIFTS OFF SHORE AND
LOSES ITS GRIP SLIGHTLY ON THE SOUTHEAST. ALTHOUGH IT CONTINUES TO
RIDGE DOWN TOWARD THE TENNESSEE VALLEY...A COASTAL TROUGH BECOMES
MORE PRONOUNCED AND MOVES WEST CLOSER TO THE SOUTHEAST COASTLINE.
OVERALL...THE EXACT POSITION OF THE COASTAL TROUGH OR POSSIBILITY OF
LOW DEVELOPING WILL BE THE DETERMINING FACTOR AND WILL PLAY A MAJOR
ROLE IN EVERYTHING FROM CLOUD COVER TO TEMPS IN THE LONG TERM. AT
THIS POINT...LOOKING AT THE LATEST MODEL RUNS...WILL KEEP WITH ONLY
SLIGHT CHC POPS ALONG THE COASTAL COUNTIES WITH PERHAPS SLIGHTLY
GREATER CHC ON MON AFTN WITH POSSIBILITY OF SFC LOW FORMING OFF THE
COAST AND AND THEN AGAIN ON FRI AS COASTAL TROUGH BECOMES MUCH MORE
PRONOUNCED. KEPT CLOUD COVER IN MOST OF THE EXTENDED ESPECIALLY
ALONG THE COAST.
TEMPS SHOULD BASICALLY RUN AROUND NORMAL WITH LOWS IN THE LOWER 60S
AND HIGH TEMPS WITHIN A FEW DEGREES OF 80.
&&
.AVIATION /00Z SATURDAY THROUGH TUESDAY/...
HIGH PRESSURE REMAINS IN CONTROL. BACKED OFF A BIT ON THE STRATUS
CEILING. FEEL THERE WILL BE TOO MUCH MIXING TO SUPPORT LOW CLOUDS.
SHOULD GET A STRATA CU CEILING...BUT VFR. WINDS WILL PICK UP AFTER
SUNRISE AGAIN SATURDAY...ALTHOUGH THE WINDS WILL BE LESS GUSTY THAN
TODAY. THERE WILL BE A STRATA CU CEILING MOST OF THE DAY WITH
CONTINUED NORTHEAST FLOW.
OUTLOOK THROUGH MONDAY...MODELS ARE TRENDING MORE TO AN OFFSHORE LOW
SCENARIO WHERE THE MOISTURE IS FAR ENOUGH OFFSHORE TO KEEP TERMINALS
VFR THROUGH SUNDAY. SOME RETURN FLOW IS POSSIBLE MONDAY INTO TUESDAY
WITH POSSIBLE PRECIP AND MVFR CEILINGS ALONG THE COAST.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 9 PM FRIDAY...A TIGHTENED PRESSURE GRADIENT TO REMAIN ACROSS
THE AREA WATERS OVERNIGHT AND INTO SATURDAY. THIS A RESULT FROM
MODEST HIGH PRESSURE CENTERED OVER THE NORTHEAST STATES AND LOW
PRESSURE SLOWLY MOVING NE ALONG A STALLED BOUNDARY OFFSHORE FROM THE
CAROLINAS...AND REACHING THE CAPE LOOKOUT LATITUDE BY SUNRISE
SATURDAY. THIS WILL RESULT IN NE-N WINDS AROUND 25 KT OVERNIGHT...
PRODUCING 5 TO 9 FOOT SEAS...WITH 3 TO 5 FOOT SEAS NEAR SHORE DUE TO
FETCH LIMITATIONS. THE NORTH SIDE OF FRYING PAN SHOALS COULD OBSERVE
SEAS UP TO 10 FT DUE TO THEIR LOCAL SHALLOW BATHYMETRY.
THE SEAS WILL PREDOMINATELY BE OF THE WIND DRIVEN LOW PERIOD WAVES.
GIVEN ANOTHER DAY OR 2...SOME THESE WIND DRIVEN WAVES MAY GRADUATE
TO A 8 TO 9 SECOND PERIOD SWELL ...WITH THE SEAS NO LONGER BEING
COMPRISED PRIMARILY FROM THE WIND DRIVEN VARIETY. COULD SPORADICALLY
OBSERVE SHOWERS FROM THE STRATOCU TOWARD MORNING...MAINLY CLOSER TO
20 NM OUT RATHER THAN INSHORE.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...HIGH PRESSURE WILL PERSIST ACROSS THE CAROLINAS
WHILE AN AREA OF WEAK LOW PRESSURE DEVELOPS FAR OFFSHORE ALONG AN
OLD FRONT. THE LOW MAY DRIFT TOWARD THE OUTER BANKS SATURDAY NIGHT
BEFORE SLOWLY LIFT AWAY FROM THE AREA SUNDAY AND SUNDAY NIGHT. AS A
RESULT...THE PRESSURE GRADIENT WILL SUPPORT A LONG PERIOD OF
NORTH-NORTHEASTERLY WINDS THAT WILL WEAKEN BY THE END OF THE SHORT
TERM PERIOD. WAVE HEIGHTS WILL GRADUALLY SUBSIDE AS THE PRESSURE
GRADIENT WEAKENS SUNDAY AND SUNDAY NIGHT. PLAN TO KEEP THE SMALL
CRAFT ADVISORY FOR ALL OF THE COASTAL WATERS THROUGH 6 PM SATURDAY.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 3 PM FRIDAY...HIGH PRESSURE CONTINUES TO RIDGE INTO THE
SOUTHEAST WITH POSSIBLE COASTAL TROUGH BECOMING MORE PRONOUNCED
THROUGH THE PERIOD. THEREFORE NORTHEAST FLOW WILL CONTINUE THROUGH
NEXT WEEK. GRADIENT SHOULD TIGHTEN DEPENDING ON HOW COASTAL TROUGH
OR POSSIBLE DEVELOPING LOW PANS OUT. THEREFORE WINDS AND SEAS MAY
INCREASE ABOVE SCA THRESHOLDS TUES AND WED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT SATURDAY FOR AMZ250-252-
254-256.
&&
$$
SYNOPSIS...HOEHLER
NEAR TERM...HOEHLER
SHORT TERM...PFAFF
LONG TERM...GROSS-ZOUZIAS
AVIATION...LOEWENTHAL
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000
FXUS62 KRAH 200100
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
900 PM EDT FRI SEP 19 2008
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL EXTEND INTO THE MID ATLANTIC REGION
THROUGH THE WEEKEND...BRINGING COOL AND DRY CONDITIONS TO CENTRAL
NORTH CAROLINA.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 900 PM FRIDAY...
GENERALLY A PERSISTENCE FORECAST OVER THE NEXT 24 HOURS.
LATEST TEMPERATURE READINGS ACROSS THE FORECAST AREA ARE RUNNING 2
TO 4 DEGREES COOLER THAN 24 HOURS AGO...RIGHT ON PAR WITH THE 12
METER DROP IN LOW-LEVEL THICKNESSES OFF THE 00Z GSO SOUNDING. SINCE
WE ARE NOT EXPECTING ANY APPRECIABLE CHANGES WITH 4 TO 7 KTS OF BL
MIXING AND INCREASING STRATUS CLOUD COVER TOWARDS DAYBREAK...WILL
CARRY THIS 2 TO 4 DEGREE COLD BIAS INTO THE OVERNIGHT MIN. THIS WILL
SUPPORT MIN TEMPERATURES MAINLY IN THE MID 50S.
BEEFED UP CLOUD COVER DURING THE DAY ON SATURDAY...AS FORECAST
SOUNDINGS INDICATE A SLOW LIFTING AND DISSIPATING OF THE MORNING
STRATUS...SUPPORTING A SCATTERED TO BROKEN LAYER OF STRATOCU
WELL INTO THE AFTERNOON HOURS. THE GFS VERIFIED EXCEPTIONALLY WELL
WITH THICKNESSES TODAY...ADDITIONALLY THE LOCAL...IN-HOUSE
THICKNESS/TEMPERATURE SCHEME VERIFIED EXCEPTIONALLY AS WELL.
THEREFORE... MADE SOME MINOR ADJUSTMENTS TO FORECAST
HIGHS...INDICATING THE WARMEST TEMPERATURES ACROSS THE EASTERN
THIRD...WITH THE COOLEST READINGS IN THE NORTHWEST. -CBL
WINDS SHOULD BE A BIT WEAKER FOR SATURDAY... AS A PIECE OF THE RIDGE
AXIS BREAKS OFF AND TRANSLATED TO A BAGGY HIGH OVER THE MID ATLANTIC
REGION. THUS... SLACKING THE GRADIENT A BIT AROSE CENTRAL NC. SKIES
AGAIN ARE EXPECTED TO BE PARTLY SUNNY ACROSS THE AREA... WITH
AFTERNOON HIGHS IN THE MID TO UPPER 70S. -BSD
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 230 PM FRIDAY...
SATURDAY NIGHT AND SUNDAY:
THIS PORTION OF THE FCST WILL BE CHARACTERIZED BY WEAK SURFACE HIGH
PRESSURE REMAINING OVER THE MID-ATLANTIC AND CAROLINAS...WITH A WEAK
LOW OR BROAD/ELONGATED SURFACE TROUGH OFF THE SOUTHEAST/MID-ATLANTIC
COAST. ALOFT...BOTH THE GFS/NAM SHOW WEAK TROUGHING JUST WEST OF THE
APPALACHIANS OVER THE DEEP SOUTH AND TN VALLEY...WITH RIDGING ALOFT
OVER THE OH VALLEY INTO THE UPPER GREAT LAKES. NOT MUCH IN THE WAY
OF LIFT EXPECTED ACROSS CENTRAL NC ON SUNDAY...EXCEPT FOR PERHAPS A
WEAK PERTURBATION IN SW/WSW FLOW ALOFT (DOWNSTREAM OF THE WEAK UPPER
TROUGH TO OUR WEST). EVEN IF THERE ARE ANY WEAK SHORTWAVES IN SW
FLOW ALOFT...FCST SOUNDINGS SHOW AN ATMOSPHERE THAT IS PRETTY
UNSUPPORTIVE OF PRECIPITATION...WITH PWAT VALUES IN THE 0.75-1.00"
RANGE...VERY DRY LOW/MID LEVELS OVER MOST OF THE AREA...AND NO
INSTABILITY. THE BEST MOISTURE AND FORCING FOR PRECIP IS EXPECTED TO
REMAIN OFFSHORE THE CAROLINA/SOUTHEAST COAST. THEREFORE...WILL
CONTINUE TO ADVERTISE A DRY FORECAST THROUGH THIS PERIOD. LOW TEMPS
SUN MORNING COULD BE TRICKY AS THE MAV MOS GUIDANCE IS AS MUCH AS
5-10F WARMER THAN THE MET MOS GUIDANCE...WITH THE PRIMARY DIFFERENCE
DUE TO DIFFERENCES IN LOW LEVEL CLOUD COVER DURING THE EARLY MORNING
HOURS. AT THIS TIME WILL GO WITH A BLEND...ADVERTISING LOWS SUN
MORNING IN THE MID/UPPER 50S. BASED ON MORNING/AFTERNOON THICKNESSES
(1375/1390M)...HIGH TEMPS SHOULD RANGE FROM THE UPPER 70S TO NEAR
80F...LOWEST NW AND HIGHEST SE.
SUNDAY NIGHT THROUGH MONDAY NIGHT:
SFC HIGH PRESSURE IS EXPECTED TO STRENGTHEN OVER SOUTHEAST CANADA
AND NEW ENGLAND ON SUN NIGHT AND MONDAY...WITH THE PRESSURE GRADIENT
ACROSS THE CAROLINAS AND MID-ATLANTIC INCREASING THROUGHOUT THE DAY
AS THE ASSOCIATED INVERTED RIDGE AXIS STRENGTHENS AND EXTENDS DOWN
THE LEE OF THE APPALACHIANS. A WEAK/BROAD SFC TROUGH IS EXPECTED TO
REMAIN OFFSHORE THE SE COAST. ALOFT...THE WEAK UPPER TROUGH WEST OF
THE MOUNTAINS IN THE DEEP SOUTH AND TN VALLEY IS EXPECTED TO MOVE A
BIT CLOSER TO THE CAROLINAS. WILL CONTINUE TO SHOW A DRY FCST WITH
LITTLE IN THE WAY OF LIFT (WEAK PERTURBATIONS ALOFT POSSIBLE).
AGAIN... THE BEST MOISTURE/FORCING SHOULD REMAIN OFF THE SE COAST.
FCST SOUNDINGS SHOW NORTHEAST FLOW IN THE MIXED LAYER INCREASING TO
15-20 KNOTS BY 21Z...AND WILL SHOW SUSTAINED NORTHEAST WINDS AT
10-15 MPH WITH GUSTS UP TO 20 MPH...PRIMARILY IN THE EASTERN HALF OF
THE AREA WHERE THE GRADIENT WILL BE TIGHTER. LOW TEMPS MON MORNING
SIMILAR BUT SLIGHTLY WARMER THAN SUN MORNING...IN THE MID/UPPER 50S.
HIGH TEMPS ON MONDAY MAY VERY WELL BE THE WARMEST OF THE WEEK...
WITH THICKNESSES SUGGESTING UPPER 70S TO LOWER 80S (78-81F). LOW
TEMPS TUE MORNING IN THE UPPER 50S TO LOWER 60S. -VINCENT
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 PM FRIDAY...
MOST OF THE EXTENDED PERIOD CONTINUES TO LOOK DRY...WITH PRONOUNCED
SFC RIDGING ASSOC/W HIGH PRESSURE IN NEW ENGLAND (OR JUST OFF THE
NEW ENGLAND COAST) EXTENDING SOUTH THROUGH THE MID-ATLANTIC INTO THE
CAROLINAS. NO MOIST/OVERRUNNING FLOW IS EXPECTED BASED ON THE LATEST
GFS/ECMWF RUNS...SO THIS SHOULD BE A DRY SFC RIDGE AXIS IN CONTRAST
TO A WEDGE/CAD SETUP. UNCERTAINTY INCREASES BY LATE WEEK AS THE
GFS/ECMWF ARE OFFERING DIFFERENT SOLUTIONS W/RESPECT TO A POTENTIAL
LOW PRESSURE SYSTEM DEVELOPING OFF THE SOUTHEAST COAST. ALTHOUGH WE
WILL NEED TO KEEP AN EYE OUT FOR THE POSSIBILITY OF A DEEP LOW
PRESSURE SYSTEM DEVELOPING OFF THE SOUTHEAST COAST BY THU/FRI...AT
THIS TIME CONFIDENCE IS JUST TOO LOW TO REFLECT MUCH OF A CHANGE IN
THE FCST BY THE END OF THE WEEK...AND WILL CONTINUE TO BASE THE FCST
ON A PATTERN OF SFC RIDGING EXTENDING INTO THE AREA FROM THE
NORTH...AND A WEAK AREA OF LOW PRESSURE WELL OFFSHORE. THIS YIELDS
HIGH TEMPS GENERALLY IN THE MID TO UPPER 70S...WITH LOWS IN THE
MID/UPPER 50S. -VINCENT
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 830 PM...
EXPECT LOW LEVEL WIND SHEAR IN THE EAST TO MEET CRITERIA AFTER
MIDNIGHT. SURFACE WINDS AT 5 TO 10 KNOTS SHOULD WEAKEN WITH TIME
WHILE NORTHEAST WINDS ABOVE THE BOUNDARY INCREASE SLIGHTLY TO 25 TO
30 KNOTS. CONDITIONS LASTING UNTIL A COUPLE OF HOURS AFTER SUNRISE.
THE PRESSURE GRADIENT ALOFT IS EXPECTED TO WEAKEN FOR SATURDAY
NIGHT...WITH SHEAR CRITERIA NOT FORECAST TO BE MET.
LOW STRATUS IS EXPECTED TO DEVELOP OR ADVECT OVER THE AREA LATER
TONIGHT. MOSTLY IFR EAST AND MVFR CEILING WEST... LIFTING TO MVFR
ALL AREAS A FEW HOURS AFTER SUNRISE. MVFR CEILINGS MAY PERSIST
INTO THE AFTERNOON.
BEYOND 18Z SATURDAY... GENERAL VFR CONDITIONS WILL PERSIST THROUGH
MIDNIGHT MONDAY NIGHT WITH HIGH PRESSURE RIDGING IN FROM THE
NORTH. SOME STRATUS AND FOG POSSIBLE BEFORE DAWN TUESDAY. VFR
CONDITIONS EXPECTED TUESDAY AFTERNOON THROUGH WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BSD
NEAR TERM...CBL/BSD
SHORT TERM...VINCENT
LONG TERM...VINCENT
AVIATION...RLH
000
FXUS62 KRAH 200030
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
830 PM EDT FRI SEP 19 2008
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL EXTEND INTO THE MID ATLANTIC REGION
THROUGH THE WEEKEND...BRINGING COOL AND DRY CONDITIONS TO CENTRAL
NORTH CAROLINA.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 245 PM FRIDAY...
HIGH PRESSURE LOCATED OVER NEW ENGLAND WILL CONTINUES TO RIDGE DOWN
THE EASTERN SEABOARD THE REST OF THIS AFTERNOON INTO TONIGHT. THIS
WILL YIELD ANOTHER PLEASANT DRY EARLY FALL LIKE AFTERNOON ACROSS
CENTRAL NORTH CAROLINA. WINDS WILL BE A BIT GUSTY OUT OF THE
NORTHEAST THIS AFTERNOON AS THE PRESSURE GRADIENT REMAINS TIGHT..
AND COUPLED WITH STRONGER WINDS ALOFT MIXING DOWN TO THE SURFACE.
EXPECT WINDS TO GENERALLY BE BETWEEN 10 TO 15 MPH... WITH GUST AS
HIGH AS 25 MPH... ESPECIALLY IN THE COASTAL PLAIN WHERE THE PRESSURE
GRADIENT WILL BE THE TIGHTEST.
FOR TONIGHT CLOUDS WILL BEGIN TO DISSIPATE WITH LACK OF DAYTIME
HEATING. HOWEVER... EXPECT LOW STRATUS TO FORM AFTER MIDNIGHT AS
BOTH THE NAM AND THE GFS DEPICT A SLUG OF MOISTURE ADVECTING IN OFF
OF THE ATLANTIC IN THE LOW LEVELS OF THE ATMOSPHERE WITH THE
NORTHEAST FLOW. THE CLOUD COVER OVERNIGHT SHOULD PREVENT OVERNIGHT
LOWS FROM DROPPING TO STATISTICAL GUIDANCE LOWS. EXPECT LOWS
OVERNIGHT TO RANGE FROM THE MID 50S IN THE NORTHWEST TO THE UPPER
50S ELSEWHERE.
SATURDAY APPEARS TO BE ANOTHER STELLAR FALL LIKE DAY... AFTER THE
LOW STRATUS LIFTS... WHICH WILL BE MORE PREVALENT FROM RALEIGH
EASTWARD. WINDS SHOULD BE A BIT WEAKER FOR SATURDAY... AS A PIECE OF
THE RIDGE AXIS BREAKS OFF AND TRANSLATED TO A BAGGY HIGH OVER THE
MID ATLANTIC REGION. THUS... SLACKING THE GRADIENT A BIT AROSE
CENTRAL NORTH CAROLINA. SKIES AGAIN ARE EXPECTED TO BE PARTLY
SUNNY ACROSS THE AREA... WITH AFTERNOON HIGHS IN THE MID TO UPPER
70S. -BSD
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 230 PM FRIDAY...
SATURDAY NIGHT AND SUNDAY:
THIS PORTION OF THE FORECAST WILL BE CHARACTERIZED BY WEAK SURFACE HIGH
PRESSURE REMAINING OVER THE MID-ATLANTIC AND CAROLINAS...WITH A WEAK
LOW OR BROAD/ELONGATED SURFACE TROUGH OFF THE SOUTHEAST/MID-ATLANTIC
COAST. ALOFT...BOTH THE GFS/NAM SHOW WEAK TROUGHING JUST WEST OF THE
APPALACHIANS OVER THE DEEP SOUTH AND TN VALLEY...WITH RIDGING ALOFT
OVER THE OH VALLEY INTO THE UPPER GREAT LAKES. NOT MUCH IN THE WAY
OF LIFT EXPECTED ACROSS CENTRAL NC ON SUNDAY...EXCEPT FOR PERHAPS A
WEAK PERTURBATION IN SW/WSW FLOW ALOFT (DOWNSTREAM OF THE WEAK UPPER
TROUGH TO OUR WEST). EVEN IF THERE ARE ANY WEAK SHORTWAVES IN
SOUTHWEST FLOW ALOFT...FORECAST SOUNDINGS SHOW AN ATMOSPHERE THAT
IS PRETTY UNSUPPORTIVE OF PRECIPITATION...WITH PRECIPITABLE WATER
VALUES IN THE 0.75 TO 1.00 INCH RANGE...VERY DRY LOW/MID LEVELS
OVER MOST OF THE AREA...AND NO INSTABILITY. THE BEST MOISTURE AND
FORCING FOR PRECIPITATION IS EXPECTED TO REMAIN OFFSHORE THE
CAROLINA/SOUTHEAST COAST. THEREFORE...WILL CONTINUE TO ADVERTISE A
DRY FORECAST THROUGH THIS PERIOD. LOW TEMPERATURES SUNDAY MORNING
COULD BE TRICKY AS THE MAV MOS GUIDANCE IS AS MUCH AS 5 TO 10F
WARMER THAN THE MET MOS GUIDANCE...WITH THE PRIMARY DIFFERENCE DUE
TO DIFFERENCES IN LOW LEVEL CLOUD COVER DURING THE EARLY MORNING
HOURS. AT THIS TIME WILL GO WITH A BLEND...ADVERTISING LOWS SUNDAY
MORNING IN THE MID TO UPPER 50S. BASED ON MORNING/AFTERNOON
THICKNESSES (1375/1390 METERS)...HIGH TEMPERATURES SHOULD RANGE
FROM THE UPPER 70S TO NEAR 80F...LOWEST NORTHWEST AND HIGHEST
SOUTHEAST.
SUNDAY NIGHT THROUGH MONDAY NIGHT:
SURFACE HIGH PRESSURE IS EXPECTED TO STRENGTHEN OVER SOUTHEAST
CANADA AND NEW ENGLAND ON SUN NIGHT AND MONDAY...WITH THE PRESSURE
GRADIENT ACROSS THE CAROLINAS AND MID-ATLANTIC INCREASING
THROUGHOUT THE DAY AS THE ASSOCIATED INVERTED RIDGE AXIS
STRENGTHENS AND EXTENDS DOWN THE LEE OF THE APPALACHIANS. A WEAK
BROAD SURFACE TROUGH IS EXPECTED TO REMAIN OFFSHORE THE SE COAST.
ALOFT...THE WEAK UPPER TROUGH WEST OF THE MOUNTAINS IN THE DEEP
SOUTH AND TN VALLEY IS EXPECTED TO MOVE A BIT CLOSER TO THE
CAROLINAS. WILL CONTINUE TO SHOW A DRY FORECAST WITH LITTLE IN THE
WAY OF LIFT (WEAK PERTURBATIONS ALOFT POSSIBLE). AGAIN... THE BEST
MOISTURE/FORCING SHOULD REMAIN OFF THE SE COAST. FORECAST
SOUNDINGS SHOW NORTHEAST FLOW IN THE MIXED LAYER INCREASING TO 15
TO 20 KNOTS BY 21Z...AND WILL SHOW SUSTAINED NORTHEAST WINDS AT 10
TO 15 MPH WITH GUSTS UP TO 20 MPH...PRIMARILY IN THE EASTERN HALF
OF THE AREA WHERE THE GRADIENT WILL BE TIGHTER. LOW TEMPERATURES
MONDAY MORNING SIMILAR BUT SLIGHTLY WARMER THAN SUN MORNING...IN
THE MID TO UPPER 50S. HIGH TEMPERATURES ON MONDAY MAY VERY WELL BE
THE WARMEST OF THE WEEK... WITH THICKNESSES SUGGESTING UPPER 70S
TO LOWER 80S (78 TO 81F). LOW TEMPS TUE MORNING IN THE UPPER 50S
TO LOWER 60S. -VINCENT
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 PM FRIDAY...
MOST OF THE EXTENDED PERIOD CONTINUES TO LOOK DRY...WITH PRONOUNCED
SFC RIDGING ASSOCIATED WITH HIGH PRESSURE IN NEW ENGLAND (OR JUST
OFF THE NEW ENGLAND COAST) EXTENDING SOUTH THROUGH THE MID-
ATLANTIC INTO THE CAROLINAS. NO MOIST/OVERRUNNING FLOW IS EXPECTED
BASED ON THE LATEST GFS/ECMWF RUNS...SO THIS SHOULD BE A DRY
SURFACE RIDGE AXIS IN CONTRAST TO A WEDGE/CAD SETUP. UNCERTAINTY
INCREASES BY LATE WEEK AS THE GFS/ECMWF ARE OFFERING DIFFERENT
SOLUTIONS WITH RESPECT TO A POTENTIAL LOW PRESSURE SYSTEM
DEVELOPING OFF THE SOUTHEAST COAST. ALTHOUGH WE WILL NEED TO KEEP
AN EYE OUT FOR THE POSSIBILITY OF A DEEP LOW PRESSURE SYSTEM
DEVELOPING OFF THE SOUTHEAST COAST BY THU/FRI...AT THIS TIME
CONFIDENCE IS JUST TOO LOW TO REFLECT MUCH OF A CHANGE IN THE
FORECAST BY THE END OF THE WEEK...AND WILL CONTINUE TO BASE THE
FORECAST ON A PATTERN OF SFC RIDGING EXTENDING INTO THE AREA FROM
THE NORTH...AND A WEAK AREA OF LOW PRESSURE WELL OFFSHORE. THIS
YIELDS HIGH TEMPERATURES GENERALLY IN THE MID TO UPPER 70S...WITH
LOWS IN THE MID/UPPER 50S. -VINCENT
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 830 PM...
EXPECT LOW LEVEL WIND SHEAR IN THE EAST TO MEET CRITERIA AFTER
MIDNIGHT. SURFACE WINDS AT 5 TO 10 KNOTS SHOULD WEAKEN WITH TIME
WHILE NORTHEAST WINDS ABOVE THE BOUNDARY INCREASE SLIGHTLY TO 25 TO
30 KNOTS. CONDITIONS LASTING UNTIL A COUPLE OF HOURS AFTER
SUNRISE. THE PRESSURE GRADIENT ALOFT IS EXPECTED TO WEAKEN FOR
SATURDAY NIGHT...WITH SHEAR CRITERIA NOT FORECAST TO BE MET.
LOW STRATUS IS EXPECTED TO DEVELOP OR ADVECT OVER THE AREA LATER
TONIGHT. MOSTLY IFR EAST AND MVFR CEILING WEST... LIFTING TO MVFR
ALL AREAS A FEW HOURS AFTER SUNRISE. MVFR CEILINGS MAY PERSIST
INTO THE AFTERNOON.
BEYOND 18Z SATURDAY... GENERAL VFR CONDITIONS WILL PERSIST THROUGH
MIDNIGHT MONDAY NIGHT WITH HIGH PRESSURE RIDGING IN FROM THE
NORTH. SOME STRATUS AND FOG POSSIBLE BEFORE DAWN TUESDAY. VFR
CONDITIONS EXPECTED TUESDAY AFTERNOON THROUGH WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
[top]
000
FXUS62 KMHX 200023
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
822 PM EDT FRI SEP 19 2008
.SYNOPSIS...
STRONG HIGH PRESSURE WILL CONTINUE RIDGING SW OVER THE AREA FROM THE
CANADIAN MARITIMES THROUGH SATURDAY...WHILE A SLOW MOVING FRONTAL
SYSTEM REMAINS OFFSHORE. A WAVE OF LOW PRESSURE WILL MOVE SLOWLY
NE ALONG THE FRONT OVER THE WEEKEND. HIGH PRESSURE WILL WEAKEN
SUNDAY AND MONDAY...BUT A STRONGER REINFORCING SHOT OF HIGH
PRESSURE IS EXPECTED TO BUILD INTO THE AREA THROUGH MID NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
MOISTURE IS EXPECTED TO GRADUALLY INCREASE OVERNIGHT AS WEAK AREA OF
LOW PRESSURE WELL OFFSHORE MOVES A BIT CLOSER TO THE COAST. BASED ON
CURRENT RDR TRENDS DELAYED PRECIP NEAR THE COAST TIL LATER TONIGHT
AND REMOVED ANY MENTION OF TSRA EXCEPT FOR CSTL WTRS. LOWERED TEMPS
A BIT FOR THE OBX AND SOUNDS BASED ON CURRENT READING ALREADY AROUND
70.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
WAVE OF LOW PRES ALONG FRONT OFFSHORE IS EXPECTED TO LIFT SLOWLY NE
THROUGH THE WEEKEND. THE GFS SOLUTION CLOSER TO THE COAST WITH
DEEPER MOISTURE SEEMS LIKE A LITTLE BIT OF AN OUTLIER SO HAVE
GENERALLY GONE WITH A BLEND FOR PRECIP THIS WEEKEND WHICH CONTINUES
TO ADVERTISE CHC POPS NEAR THE CENTRAL OUTER BANKS AND A SLIGHT
CHANCE ELSEWHERE E OF HIGHWAY 17...AND DRY ELSEWHERE. REALLY CANT
RULE OUT A STRAY SHOWER INLAND BUT THINK DEEPER DRIER AIR OVER THE
COASTAL PLAIN WILL PREVENT MUCH FROM MEASURING. WILL KEEP TSTM
MENTION ONLY NEAR THE CENTRAL OUTER BANKS AND ADJACENT WATERS WERE
MARGINAL INSTABILITY EXPECTED...WHICH IS ALSO CONSISTENT WITH DAY 2
GENERAL TSTM OUTLOOK FROM SPC. AFTER THE WAVE OF LOW PRES LIFTS N
SUN NITE INTO MON PRECIP CHANCES SHOULD DIMINISH A BIT AS DRIER AIR
NOSES IN FROM THE N ON BACK SIDE OF THE LOW...BUT WILL KEEP A SCHC
ESP NEAR THE S COAST WITH MODELS INIDICATED A REMNANT BAROCLINIC
ZONE WILL REMAIN OFFSHORE.
STILL LOOKING AT SLIGHTLY COOLER THAN NORMAL TEMPS ON SAT WITH ONLY
SLIGHTLY WEAKER NE FLOW EXPECTED IN ADDITION TO PERIODS OF
STRATOCUMULUS CLOUDS. LOW TEMPS SAT NITE ARE PROBLEMATIC WITH QUITE
A SPREAD BETWEEN THE MAV/MET NUMBERS...WITH THE NAM MUCH COOLER WITH
LESS CLOUDS AND SLIGHTLY WEAKER WINDS INLAND. GIVEN THE PREFERRED
BLEND IN THE SFC LOW TRACK (A LITTLE FURTHER OFFSHORE THAN THE
GFS)...NOT GOING AS WARM AS MAV BUT THINK NAM IS A LITTLE TOO COOL
AT THIS POINT. OVERALL U50S INLAND WITH 60S NR COAST. SLIGHTLY
WARMER BUT NEAR CLIMO TEMPS EXPECTED SUN AND MON.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
STRONG SFC HIGH PRES RIDGING IN FROM THE NORTH WILL REINFORCE OVER
THE AREA EARLY TO MID NEXT WEEK WITH CONTINUED NE FLOW AND TEMPS
SLIGHTLY COOLER THAN NORMAL...HIGHS IN MID/UPPER 70S. WILL STILL
CONTINUE SLIGHT CHANCE FOR POPS ALONG THE COAST...MAINLY E OF HWY
17...FOR MUCH OF THE PERIOD WITH TROUGH LINGERING AND FRONT
OFFSHORE. BOTH GFS/ECMWF/HPC CONTINUE TO SHOW LOW PRESSURE
DEVELOPING OFF THE COAST LATE NEXT WEEK...SO WILL NEED TO CONTINUE
TO MONITOR THAT AS WE HEAD INTO NEXT WEEKEND.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
NORTHEAST SURFACE WINDS WILL CONTINUE OVERNIGHT AROUND 10 KNOTS.
EXPECTING EXPECTING STRATOCU DECK TO COME IN AFTER MIDNIGHT AND
LINGER INTO SATURDAY. WINDS WILL BE GUSTY AGAIN ON SATURDAY...IN THE
MID 20S.
THE NE FLOW WILL CONTINUE THROUGH THE REST OF THE FORECAST...WITH
GUSTY WINDS ESPECIALLY TUESDAY AND WEDNESDAY. TREND IN LATEST
GUIDANCE IS TO KEEP DEEPEST MOISTURE EAST OF THE AREA SP THINKING
MAINLY VFR CONDITIONS OUTSIDE OF ANY NOCTURNAL LOW CLOUD FORMATION.
&&
.MARINE...
TIGHT PRESSURE GRADIENT ALONG THE COAST RESULTING IN WINDY CONDTIONS
MOST OBSERVATION SITES. DIAMOND BUOY HAS BEEN GUSTING TO 35 KNOTS
SINCE LATE THIS AFTERNOON. THE FORECAST FOR THE OREGON INLET TO
OCRACOKE ZONES HAS SMALL CRAFT ADVISORY GOING BUT MENTIONS GUSTS TO
35 KNOTS SO THIS IS COVERED WELL. FORECAST IS IN GOOD SHAPE. NO
CHANGES PLANNED.
THE COMBINATION OF STRONG ONSHORE WINDS...HIGH ASTRONOMICAL TIDES
AND ROUGH SEAS WILL LEAD TO HIGH SURF ADVISORY CONDITIONS AND
POSSIBLE MINOR BEACH EROSION/OVERWASH FROM HATTERAS NORTH THROUGH
SATURDAY MORNING. THE GRADIENT WILL WEAKEN SUNDAY/SUNDAY NIGHT AS
THE LOW PULLS AWAY TO THE NE ALLOWING WINDS AND SEAS TO SUBSIDE.
CONDITIONS SHOULD DROP BELOW ADVISORY CRITERIA SOUTH OF LOOKOUT
SUNDAY/SUNDAY NIGHT WITH SEAS REMAINING AT CRITERIA NORTH OF LOOKOUT
THROUGH THE FORECAST PERIOD.
STARTING EARLY NEXT WEEK ANOTHER STRONG HIGH WILL BE BUILDING TO THE
NORTH WITH MODELS SHOWING LOW PRESSURE DEVELOPING TO THE SOUTH BY
MIDWEEK. STILL LOTS OF UNCERTAINTY ON TRACK/INTENSITY OF THIS LOW
WITH THE CONSENSUS OF THE 12Z GUIDANCE INDICATING THAT THE HIGH TO
THE NORTH WILL BE THE DOMINATE FEATURE. THE HIGH WILL BE STRONG
ENOUGH TO PRODUCE AT LEAST STRONG SMALL CRAFT ADVISORY WINDS AND
SEAS TO 10 FT OR EVEN HIGHER. WE COULD BE LOOKING AT PERIOD OF MINOR
OCEAN OVERWASH/BEACH EROSION ALONG HATTERAS ISLAND AND PERHAPS A
MINOR SOUND SIDE FLOODING EVENT ADJACENT TO THE PAMLICO SOUND AND
NEUSE AND PAMLICO RIVERS.
.RIP CURRENTS...STRONG WINDS AND ROUGH SEAS WILL LEAD TO HIGH RIP
THREAT SATURDAY FOR ALL EAST FACING BEACHES FROM LOOKOUT NORTH AND A
MODERATE THREAT FROM SURF CITY TO BOGUE INLET.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...HIGH SURF ADVISORY UNTIL 8 AM EDT SATURDAY FOR NCZ103.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT SATURDAY FOR AMZ130-135.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT TUESDAY FOR AMZ150-152-154-
156.
SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR AMZ158.
&&
$$
SYNOPSIS...MW
NEAR TERM...RF
SHORT TERM...MW
LONG TERM...CQD
AVIATION...HSA/JME
MARINE...HSA/JME
000
FXUS62 KILM 192319
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
720 PM EDT FRI SEP 19 2008
.SYNOPSIS...
HIGH PRESSURE ACROSS THE NORTHEAST WILL RIDGE INTO THE CAROLINAS
THROUGH THE WEEKEND AND BRING COOLER THAN NORMAL TEMPERATURES TO THE
REGION. A TROUGH OF LOW PRESSURE WILL DEVELOP OFFSHORE AND MOVE JUST
CLOSE ENOUGH TO THE AREA TO INCREASE THE CHANCE OF SHOWERS LATE IN
THE WEEKEND AND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM FRIDAY...BREEZY NORTHEAST WINDS WILL CONTINUE THROUGH
SUNSET AND WITH PRESSURE GRADIENT WILL BE MAINTAINED AS A WEAK LOW
DEVELOPS ALONG THE OLD FRONTAL BOUNDARY OVERNIGHT TOWARDS MORNING.
POSSIBLE STRATUS ALONG THE COAST WITH STRONG WINDS AND MOISTURE
TRAPPED UNDER THE INVERSION...IF THEY DO DEVELOP EXPECT THIS CLOUD
COVER TO BREAK UP AND CLOUD STREETS TO AGAIN.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...DURING SATURDAY THE FORECAST AREA WILL BE
BETWEEN MID/UPPER RIDGE FAR OFF THE SOUTHEAST UNITED STATES COAST
AND TROUGH ACROSS THE MS VALLEY. AT THE SURFACE...A WEAK AREA OF LOW
PRESSURE OR WAVE ALONG THE OLD FRONT WILL ATTEMPT TO DRIFT TOWARD
THE OUTER BANKS BEFORE SLOWLY LIFTING AWAY. ALTHOUGH H85-H5 LAYER RH
IS NOT THAT IMPRESSIVE TRAJECTORIES IN THE 925MB LEVEL ARE
SUPPORTIVE OF MOISTURE ADVECTION INTO THE FORECAST AREA. IN FACT
THERE IS A SURGE IN LOW-LEVEL THETA-E BY SATURDAY WHICH IS MOST
LIKELY REFLECTIVE OF SLIGHTLY DEEPER MOISTURE TRYING TO ADVECT INTO
THE AREA. NOT ENTIRELY SOLD ON SIGNIFICANT AREAL COVERAGE OF SHOWERS
DURING THIS EVENT...WOULD GO HIGHER IF THE TREND WAS FOR A FARTHER
WESTWARD DRIFT IN THE LOW/WAVE. FOR NOW...WILL STICK WITH SLIGHT
CHANCE POPS...PRIMARILY FOR THE COASTAL COUNTIES. GIVEN THE FLOW
REGIME FAVOR A BLEND TOWARD THE COOLEST OF THE GUIDANCE THROUGH THE
PERIOD.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3 PM FRIDAY...HIGH PRESSURE CONTINUES TO NOSE DOWN INTO LOCAL
AREA FROM THE NORTH...WITH CENTER OF SFC HIGH IN THE VICINITY OF NEW
ENGLAND. WED INTO FRI THE CENTER OF THE HIGH SHIFTS OFF SHORE AND
LOSES ITS GRIP SLIGHTLY ON THE SOUTHEAST. ALTHOUGH IT CONTINUES TO
RIDGE DOWN TOWARD THE TENNESSEE VALLEY...A COASTAL TROUGH BECOMES
MORE PRONOUNCED AND MOVES WEST CLOSER TO THE SOUTHEAST COASTLINE.
OVERALL...THE EXACT POSITION OF THE COASTAL TROUGH OR POSSIBILITY OF
LOW DEVELOPING WILL BE THE DETERMINING FACTOR AND WILL PLAY A MAJOR
ROLE IN EVERYTHING FROM CLOUD COVER TO TEMPS IN THE LONG TERM. AT
THIS POINT...LOOKING AT THE LATEST MODEL RUNS...WILL KEEP WITH ONLY
SLIGHT CHC POPS ALONG THE COASTAL COUNTIES WITH PERHAPS SLIGHTLY
GREATER CHC ON MON AFTN WITH POSSIBILITY OF SFC LOW FORMING OFF THE
COAST AND AND THEN AGAIN ON FRI AS COASTAL TROUGH BECOMES MUCH MORE
PRONOUNCED. KEPT CLOUD COVER IN MOST OF THE EXTENDED ESPECIALLY
ALONG THE COAST.
TEMPS SHOULD BASICALLY RUN AROUND NORMAL WITH LOWS IN THE LOWER 60S
AND HIGH TEMPS WITHIN A FEW DEGREES OF 80.
&&
.AVIATION /00Z SATURDAY THROUGH TUESDAY/...
HIGH PRESSURE REMAINS IN CONTROL. BACKED OFF A BIT ON THE STRATUS
CEILING. FEEL THERE WILL BE TOO MUCH MIXING TO SUPPORT LOW CLOUDS.
SHOULD GET A STRATA CU CEILING...BUT VFR. WINDS WILL PICK UP AFTER
SUNRISE AGAIN SATURDAY...ALTHOUGH THE WINDS WILL BE LESS GUSTY THAN
TODAY. THERE WILL BE A STRATA CU CEILING MOST OF THE DAY WITH
CONTINUED NORTHEAST FLOW.
OUTLOOK THROUGH MONDAY...MODELS ARE TRENDING MORE TO AN OFFSHORE LOW
SCENARIO WHERE THE MOISTURE IS FAR ENOUGH OFFSHORE TO KEEP TERMINALS
VFR THROUGH SUNDAY. SOME RETURN FLOW IS POSSIBLE MONDAY INTO TUESDAY
WITH POSSIBLE PRECIP AND MVFR CEILINGS ALONG THE COAST.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM FRIDAY...A TIGHT PRESSURE GRADIENT RESULTING FROM HIGH
PRESSURE OVER MAINE AND AN OLD FRONT OFF THE COAST IS PRODUCING
STRONG NORTHEAST WINDS. AT 3 PM FRYING PAN WAS REPORTING NORTHEAST
WINDS OF 25 KNOTS AND SEAS OF 9.5 FEET. CLOSE TO THE COAST SEAS 5 TO
6 FEET WERE BEING OBSERVED. AS THE PRESSURE GRADIENT CONTINUES
THROUGH TONIGHT SEAS AND WINDS WILL REMAIN HIGH AND SMALL CRAFT
CONDITIONS WILL CONTINUE INTO SATURDAY.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...HIGH PRESSURE WILL PERSIST ACROSS THE CAROLINAS
WHILE AN AREA OF WEAK LOW PRESSURE DEVELOPS FAR OFFSHORE ALONG AN
OLD FRONT. THE LOW MAY DRIFT TOWARD THE OUTER BANKS SATURDAY NIGHT
BEFORE SLOWLY LIFT AWAY FROM THE AREA SUNDAY AND SUNDAY NIGHT. AS A
RESULT...THE PRESSURE GRADIENT WILL SUPPORT A LONG PERIOD OF
NORTH-NORTHEASTERLY WINDS THAT WILL WEAKEN BY THE END OF THE SHORT
TERM PERIOD. WAVE HEIGHTS WILL GRADUALLY SUBSIDE AS THE PRESSURE
GRADIENT WEAKENS SUNDAY AND SUNDAY NIGHT. PLAN TO KEEP THE SMALL
CRAFT ADVISORY FOR ALL OF THE COASTAL WATERS THROUGH 6 PM SATURDAY.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 3 PM FRIDAY...HIGH PRESSURE CONTINUES TO RIDGE INTO THE
SOUTHEAST WITH POSSIBLE COASTAL TROUGH BECOMING MORE PRONOUNCED
THROUGH THE PERIOD. THEREFORE NORTHEAST FLOW WILL CONTINUE THROUGH
NEXT WEEK. GRADIENT SHOULD TIGHTEN DEPENDING ON HOW COASTAL TROUGH
OR POSSIBLE DEVELOPING LOW PANS OUT. THEREFORE WINDS AND SEAS MAY
INCREASE ABOVE SCA THRESHOLDS TUES AND WED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT SATURDAY FOR AMZ250-252-
254-256.
&&
$$
SYNOPSIS...SRP
NEAR TERM...HAWKINS
SHORT TERM...SRP
LONG TERM...RGZ
AVIATION...DL
000
FXUS62 KMHX 191936
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
336 PM EDT FRI SEP 19 2008
.SYNOPSIS...
STRONG HIGH PRESSURE WILL CONTINUE RIDGING SW OVER THE AREA FROM THE
CANADIAN MARITIMES THROUGH SATURDAY...WHILE A SLOW MOVING FRONTAL
SYSTEM REMAINS OFFSHORE. A WAVE OF LOW PRESSURE WILL MOVE SLOWLY
NE ALONG THE FRONT OVER THE WEEKEND. HIGH PRESSURE WILL WEAKEN
SUNDAY AND MONDAY...BUT A STRONGER REINFORCING SHOT OF HIGH
PRESSURE IS EXPECTED TO BUILD INTO THE AREA THROUGH MID NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
MAIN QUESTIONS TONIGHT WILL BE IF ANY SHOWERS SNEAK IN OFF THE ATLC
AND EXTENT OF LOW CLOUDS. AGREE WITH PREVIOUS FORECAST THINKING THAT
ANY SHOWERS WILL BE CONFINED TO THE COAST CLOSER TO BAROCLINICITY
OFFSHORE AND DEEPER MOISTURE...SO HAVE LOW CHC NEAR CENTRAL OBX AND
SCHC FOR OTHER SURROUNDING COASTAL LOCALES. WILL KEEP COASTAL PLAIN
DRY PER THIS THINKING AND MODEL CONSENSUS.
THINK THE DIURNALLY ENHANCED CLOUDS OVER THE AREA ATTM WILL DIMINISH
SOME THIS EVENING...THEN THINK ERN NC WILL SEE MORE LOW CLOUDS LATER
TONIGHT BASED ON MODEL TIME SECTIONS...AND ONSHORE FLOW TRAPPING
MOISTURE UNDER A STRENGTHENING INVERSION ASSOCIATED WITH BOTH
NOCTURNAL INFLUENCES AND SUBSIDENCE ASSOCIATED WITH SHORT WAVE MID
LVL RIDGING BUILDING OVERHEAD. NE WINDS NOT EXPECTED TO DECOUPLE
TONIGHT WITH SFC PRES GRADIENT REMAINING PINCHED...BUT STILL
EXPECTING LOWS TO DROP INTO THE U50S/NR 60 INLAND TO U60S OBX WITH
CURRENT FALL LIKE AIR MASS IN PLACE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
WAVE OF LOW PRES ALONG FRONT OFFSHORE IS EXPECTED TO LIFT SLOWLY NE
THROUGH THE WEEKEND. THE GFS SOLUTION CLOSER TO THE COAST WITH
DEEPER MOISTURE SEEMS LIKE A LITTLE BIT OF AN OUTLIER SO HAVE
GENERALLY GONE WITH A BLEND FOR PRECIP THIS WEEKEND WHICH CONTINUES
TO ADVERTISE CHC POPS NEAR THE CENTRAL OUTER BANKS AND A SLIGHT
CHANCE ELSEWHERE E OF HIGHWAY 17...AND DRY ELSEWHERE. REALLY CANT
RULE OUT A STRAY SHOWER INLAND BUT THINK DEEPER DRIER AIR OVER THE
COASTAL PLAIN WILL PREVENT MUCH FROM MEASURING. WILL KEEP TSTM
MENTION ONLY NEAR THE CENTRAL OUTER BANKS AND ADJACENT WATERS WERE
MARGINAL INSTABILITY EXPECTED...WHICH IS ALSO CONSISTENT WITH DAY 2
GENERAL TSTM OUTLOOK FROM SPC. AFTER THE WAVE OF LOW PRES LIFTS N
SUN NITE INTO MON PRECIP CHANCES SHOULD DIMINISH A BIT AS DRIER AIR
NOSES IN FROM THE N ON BACK SIDE OF THE LOW...BUT WILL KEEP A SCHC
ESP NEAR THE S COAST WITH MODELS INIDICATED A REMNANT BAROCLINIC
ZONE WILL REMAIN OFFSHORE.
STILL LOOKING AT SLIGHTLY COOLER THAN NORMAL TEMPS ON SAT WITH ONLY
SLIGHTLY WEAKER NE FLOW EXPECTED IN ADDITION TO PERIODS OF
STRATOCUMULUS CLOUDS. LOW TEMPS SAT NITE ARE PROBLEMATIC WITH QUITE
A SPREAD BETWEEN THE MAV/MET NUMBERS...WITH THE NAM MUCH COOLER WITH
LESS CLOUDS AND SLIGHTLY WEAKER WINDS INLAND. GIVEN THE PREFERRED
BLEND IN THE SFC LOW TRACK (A LITTLE FURTHER OFFSHORE THAN THE
GFS)...NOT GOING AS WARM AS MAV BUT THINK NAM IS A LITTLE TOO COOL
AT THIS POINT. OVERALL U50S INLAND WITH 60S NR COAST. SLIGHTLY
WARMER BUT NEAR CLIMO TEMPS EXPECTED SUN AND MON.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
STRONG SFC HIGH PRES RIDGING IN FROM THE NORTH WILL REINFORCE OVER
THE AREA EARLY TO MID NEXT WEEK WITH CONTINUED NE FLOW AND TEMPS
SLIGHTLY COOLER THAN NORMAL...HIGHS IN MID/UPPER 70S. WILL STILL
CONTINUE SLIGHT CHANCE FOR POPS ALONG THE COAST...MAINLY E OF HWY
17...FOR MUCH OF THE PERIOD WITH TROUGH LINGERING AND FRONT
OFFSHORE. BOTH GFS/ECMWF/HPC CONTINUE TO SHOW LOW PRESSURE
DEVELOPING OFF THE COAST LATE NEXT WEEK...SO WILL NEED TO CONTINUE
TO MONITOR THAT AS WE HEAD INTO NEXT WEEKEND.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
NE WINDS WILL CONTINUE TO GUST TO AROUND 25 KT THROUGH 00Z. CEILINGS
AND VISIBILITIES WILL REMAIN VFR UNTIL AFTER MIDNIGHT. ALL OF THE
GUIDANCE IS INDICATING EASTERLY FLOW JUST OFF THE SURFACE WHICH
SHOULD LEAD TO THE DEVELOPMENT OF LOW STRATUS CLOUDS LATE
TONIGHT/EARLY SATURDAY. THE GUIDANCE IS INDICATING LIFR/IFR CEILINGS
NEAR THE COAST AND MVFR INLAND. WILL FORECAST MVFR CEILINGS WITH
THIS PACKAGE BUT SUBSEQUENT FORECASTS MAY NEED TO LOWER TO IFR/LIFR
(ESPECIALLY COASTAL TAF SITES) IF TRENDS CONTINUE. STRATUS WILL
DEVELOP INTO HIGHER BASED STRATOCUMULUS BY AFTERNOON WITH A RETURN
TO VFR CONDITIONS. COULD SEE A REPEAT OF THIS PROCESS SATURDAY
NIGHT/EARLY SUNDAY. WINDS WILL BE GUSTY AGAIN SATURDAY BUT CLOSER TO
20 KT. CURRENT THINKING IS TO KEEP BULK OF RAINFALL WITH COASTAL
LOW OFF THE COAST AND EAST OF TAF SITES THROUGH THE WEEKEND.
THE NE FLOW WILL CONTINUE THROUGH THE REST OF THE FORECAST...WITH
GUSTY WINDS ESPECIALLY TUESDAY AND WEDNESDAY. TREND IN LATEST
GUIDANCE IS TO KEEP DEEPEST MOISTURE EAST OF THE AREA SP THINKING
MAINLY VFR CONDITIONS OUTSIDE OF ANY NOCTURNAL LOW CLOUD FORMATION.
&&
.MARINE...
NO SIGNIFICANT CHANGES TO THE CURRENT FORECAST THINKING. THE
GRADIENT BETWEEN STRONG HIGH PRESSURE TO THE NORTH AND WEAK LOW
PRESSURE ALONG A STALLED FRONTAL BOUNDARY TO THE SE WILL PRODUCE
STRONG SMALL CRAFT ADVISORY CONDITIONS (25-30 KT) WITH A FEW GUSTS
TO 35 KT. THESE CONDITIONS WILL PERSIST THROUGH SATURDAY WITH SEAS
REACHING 10 FT OR HIGHER. THE LOW IS FORECAST TO MOVE SLOWLY NW
ACROSS THE NC WATERS TONIGHT THROUGH SATURDAY NIGHT...THEN LIFT NE
OF THE WATERS AND WEAKEN SUNDAY.
THE COMBINATION OF STRONG ONSHORE WINDS...HIGH ASTRONOMICAL TIDES
AND ROUGH SEAS WILL LEAD TO HIGH SURF ADVISORY CONDITIONS AND
POSSIBLE MINOR BEACH EROSION/OVERWASH FROM HATTERAS NORTH THROUGH
SATURDAY MORNING. THE GRADIENT WILL WEAKEN SUNDAY/SUNDAY NIGHT AS
THE LOW PULLS AWAY TO THE NE ALLOWING WINDS AND SEAS TO SUBSIDE.
CONDITIONS SHOULD DROP BELOW ADVISORY CRITERIA SOUTH OF LOOKOUT
SUNDAY/SUNDAY NIGHT WITH SEAS REMAINING AT CRITERIA NORTH OF LOOKOUT
THROUGH THE FORECAST PERIOD.
STARTING EARLY NEXT WEEK ANOTHER STRONG HIGH WILL BE BUILDING TO THE
NORTH WITH MODELS SHOWING LOW PRESSURE DEVELOPING TO THE SOUTH BY
MIDWEEK.
STILL LOTS OF UNCERTAINTY ON TRACK/INTENSITY OF THIS LOW WITH THE
CONSENSUS OF THE 12Z GUIDANCE INDICATING THAT THE HIGH TO THE NORTH
WILL BE THE DOMINATE FEATURE. THE HIGH WILL BE STRONG ENOUGH TO
PRODUCE AT LEAST STRONG SMALL CRAFT ADVISORY WINDS AND SEAS TO 10 FT
OR EVEN HIGHER. WE COULD BE LOOKING AT PERIOD OF MINOR OCEAN
OVERWASH/BEACH EROSION ALONG HATTERAS ISLAND AND PERHAPS A MINOR
SOUND SIDE FLOODING EVENT ADJACENT TO THE PAMLICO SOUND AND NEUSE
AND PAMLICO RIVERS.
.RIP CURRENTS...STRONG WINDS AND ROUGH SEAS WILL LEAD TO HIGH RIP
THREAT SATURDAY FOR ALL EAST FACING BEACHES FROM LOOKOUT NORTH AND A
MODERATE THREAT FROM SURF CITY TO BOGUE INLET.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...HIGH SURF ADVISORY UNTIL 8 AM EDT SATURDAY FOR NCZ103.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT SATURDAY FOR AMZ130-135.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT TUESDAY FOR AMZ150-152-154-
156.
SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR AMZ158.
&&
$$
SYNOPSIS...MW
NEAR TERM...MW
SHORT TERM...MW
LONG TERM...CQD
AVIATION...JME
MARINE...JME
000
FXUS62 KILM 191931
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
330 PM EDT FRI SEP 19 2008
.SYNOPSIS...
HIGH PRESSURE ACROSS THE NORTHEAST WILL RIDGE INTO THE CAROLINAS
THROUGH THE WEEKEND AND BRING COOLER THAN NORMAL TEMPERATURES TO THE
REGION. A TROUGH OF LOW PRESSURE WILL DEVELOP OFFSHORE AND MOVE JUST
CLOSE ENOUGH TO THE AREA TO INCREASE THE CHANCE OF SHOWERS LATE IN
THE WEEKEND AND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM FRIDAY...BREEZY NORTHEAST WINDS WILL CONTINUE THROUGH
SUNSET AND WITH PRESSURE GRADIENT WILL BE MAINTAINED AS A WEAK LOW
DEVELOPS ALONG THE OLD FRONTAL BOUNDARY OVERNIGHT TOWARDS MORNING.
POSSIBLE STRATUS ALONG THE COAST WITH STRONG WINDS AND MOISTURE
TRAPPED UNDER THE INVERSION...IF THEY DO DEVELOP EXPECT THIS CLOUD
COVER TO BREAK UP AND CLOUD STREETS TO AGAIN.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...DURING SATURDAY THE FORECAST AREA WILL BE
BETWEEN MID/UPPER RIDGE FAR OFF THE SOUTHEAST UNITED STATES COAST
AND TROUGH ACROSS THE MS VALLEY. AT THE SURFACE...A WEAK AREA OF LOW
PRESSURE OR WAVE ALONG THE OLD FRONT WILL ATTEMPT TO DRIFT TOWARD
THE OUTER BANKS BEFORE SLOWLY LIFTING AWAY. ALTHOUGH H85-H5 LAYER RH
IS NOT THAT IMPRESSIVE TRAJECTORIES IN THE 925MB LEVEL ARE
SUPPORTIVE OF MOISTURE ADVECTION INTO THE FORECAST AREA. IN FACT
THERE IS A SURGE IN LOW-LEVEL THETA-E BY SATURDAY WHICH IS MOST
LIKELY REFLECTIVE OF SLIGHTLY DEEPER MOISTURE TRYING TO ADVECT INTO
THE AREA. NOT ENTIRELY SOLD ON SIGNIFICANT AREAL COVERAGE OF SHOWERS
DURING THIS EVENT...WOULD GO HIGHER IF THE TREND WAS FOR A FARTHER
WESTWARD DRIFT IN THE LOW/WAVE. FOR NOW...WILL STICK WITH SLIGHT
CHANCE POPS...PRIMARILY FOR THE COASTAL COUNTIES. GIVEN THE FLOW
REGIME FAVOR A BLEND TOWARD THE COOLEST OF THE GUIDANCE THROUGH THE
PERIOD.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3 PM FRIDAY...HIGH PRESSURE CONTINUES TO NOSE DOWN INTO LOCAL
AREA FROM THE NORTH...WITH CENTER OF SFC HIGH IN THE VICINITY OF NEW
ENGLAND. WED INTO FRI THE CENTER OF THE HIGH SHIFTS OFF SHORE AND
LOSES ITS GRIP SLIGHTLY ON THE SOUTHEAST. ALTHOUGH IT CONTINUES TO
RIDGE DOWN TOWARD THE TENNESSEE VALLEY...A COASTAL TROUGH BECOMES
MORE PRONOUNCED AND MOVES WEST CLOSER TO THE SOUTHEAST COASTLINE.
OVERALL...THE EXACT POSITION OF THE COASTAL TROUGH OR POSSIBILITY OF
LOW DEVELOPING WILL BE THE DETERMINING FACTOR AND WILL PLAY A MAJOR
ROLE IN EVERYTHING FROM CLOUD COVER TO TEMPS IN THE LONG TERM. AT
THIS POINT...LOOKING AT THE LATEST MODEL RUNS...WILL KEEP WITH ONLY
SLIGHT CHC POPS ALONG THE COASTAL COUNTIES WITH PERHAPS SLIGHTLY
GREATER CHC ON MON AFTN WITH POSSIBILITY OF SFC LOW FORMING OFF THE
COAST AND AND THEN AGAIN ON FRI AS COASTAL TROUGH BECOMES MUCH MORE
PRONOUNCED. KEPT CLOUD COVER IN MOST OF THE EXTENDED ESPECIALLY
ALONG THE COAST.
TEMPS SHOULD BASICALLY RUN AROUND NORMAL WITH LOWS IN THE LOWER 60S
AND HIGH TEMPS WITHIN A FEW DEGREES OF 80.
&&
.AVIATION /18Z FRIDAY THROUGH TUESDAY/...
AVIATION PROBLEMS WILL BE WITH GUSTING WINDS AT THE COASTAL TAFS
WITH GUST EXPECTED TO REACH AROUND 25 KNOTS TONIGHT . ALSO...MODELS
ARE INDICATING LIFR/IFR STRATUS ALONG THE COAST AFTER 09 UTC. BUFR
SOUNDINGS ARE SHOWING STRATUS LAYER A BIT HIGHER IN THE MVFR RANGE
AT THE SAME TIME. SO HAVE FAVORED BUFR SOUNDINGS OVER THE NUMERICAL
GUIDANCE.
OUTLOOK THROUGH MONDAY...WITH TROUGH OF LOW PRESSURE AND MODELS
STILL NOT HONING IN ON A SIMILAR SOLUTION THERE CONTINUES TO BE
HIGHER THAN NORMAL UNCERTAINTY IN THIS PERIOD. CONDITIONS WILL
DRIVEN BY THE LOCATION AND TIMING OF THE LOW PRESSURE CENTERS THAT
TRANSVERSE THE OFFSHORE BOUNDARY AND THE DISTANCE TO THE TAFS SITES.
THE INLAND TAF SITES WILL GENERALLY BE VFR WHILE COASTAL SITES HAVE
A BETTER CHANCE OF SEEING SHOWERS AND LOWER CEILING.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM FRIDAY...A TIGHT PRESSURE GRADIENT RESULTING FROM HIGH
PRESSURE OVER MAINE AND AN OLD FRONT OFF THE COAST IS PRODUCING
STRONG NORTHEAST WINDS. AT 3 PM FRYING PAN WAS REPORTING NORTHEAST
WINDS OF 25 KNOTS AND SEAS OF 9.5 FEET. CLOSE TO THE COAST SEAS 5 TO
6 FEET WERE BEING OBSERVED. AS THE PRESSURE GRADIENT CONTINUES
THROUGH TONIGHT SEAS AND WINDS WILL REMAIN HIGH AND SMALL CRAFT
CONDITIONS WILL CONTINUE INTO SATURDAY.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...HIGH PRESSURE WILL PERSIST ACROSS THE CAROLINAS
WHILE AN AREA OF WEAK LOW PRESSURE DEVELOPS FAR OFFSHORE ALONG AN
OLD FRONT. THE LOW MAY DRIFT TOWARD THE OUTER BANKS SATURDAY NIGHT
BEFORE SLOWLY LIFT AWAY FROM THE AREA SUNDAY AND SUNDAY NIGHT. AS A
RESULT...THE PRESSURE GRADIENT WILL SUPPORT A LONG PERIOD OF
NORTH-NORTHEASTERLY WINDS THAT WILL WEAKEN BY THE END OF THE SHORT
TERM PERIOD. WAVE HEIGHTS WILL GRADUALLY SUBSIDE AS THE PRESSURE
GRADIENT WEAKENS SUNDAY AND SUNDAY NIGHT. PLAN TO KEEP THE SMALL
CRAFT ADVISORY FOR ALL OF THE COASTAL WATERS THROUGH 6 PM SATURDAY.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 3 PM FRIDAY...HIGH PRESSURE CONTINUES TO RIDGE INTO THE
SOUTHEAST WITH POSSIBLE COASTAL TROUGH BECOMING MORE PRONOUNCED
THROUGH THE PERIOD. THEREFORE NORTHEAST FLOW WILL CONTINUE THROUGH
NEXT WEEK. GRADIENT SHOULD TIGHTEN DEPENDING ON HOW COASTAL TROUGH
OR POSSIBLE DEVELOPING LOW PANS OUT. THEREFORE WINDS AND SEAS MAY
INCREASE ABOVE SCA THRESHOLDS TUES AND WED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT SATURDAY FOR AMZ250-252-
254-256.
&&
$$
SYNOPSIS...SRP
NEAR TERM...HAWKINS
SHORT TERM...SRP
LONG TERM...RGZ
AVIATION...DRH
000
FXUS62 KRAH 191906
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
306 PM EDT FRI SEP 19 2008
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL EXTEND INTO THE MID ATLANTIC REGION
THROUGH THE WEEKEND...BRINGING COOL AND DRY CONDITIONS TO CENTRAL
NORTH CAROLINA.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 245 PM FRIDAY...
HIGH PRESSURE LOCATED OVER NEW ENGLAND WILL CONTINUES TO RIDGE DOWN
THE EASTERN SEABOARD THE REST OF THIS AFTERNOON INTO TONIGHT. THIS
WILL YIELD ANOTHER PLEASANT DRY EARLY FALL LIKE AFTERNOON ACROSS
CENTRAL NORTH CAROLINA. WINDS WILL BE A BIT GUSTY OUT OF THE
NORTHEAST THIS AFTERNOON AS THE PRESSURE GRADIENT REMAINS TIGHT..
AND COUPLED WITH STRONGER WINDS ALOFT MIXING DOWN TO THE SURFACE.
EXPECT WINDS TO GENERALLY BE BETWEEN 10 TO 15 MPH... WITH GUST AS
HIGH AS 25 MPH... ESPECIALLY IN THE COASTAL PLAIN WHERE THE PRESSURE
GRADIENT WILL BE THE TIGHTEST.
FOR TONIGHT CLOUDS WILL BEGIN TO DISSIPATE WITH LACK OF DAYTIME
HEATING. HOWEVER... EXPECT LOW STRATUS TO FORM AFTER MIDNIGHT AS
BOTH THE NAM AND THE GFS DEPICT A SLUG OF MOISTURE ADVECTING IN OFF
OF THE ATLANTIC IN THE LOW LEVELS OF THE ATMOSPHERE WITH THE
NORTHEAST FLOW. THE CLOUD COVER OVERNIGHT SHOULD PREVENT OVERNIGHT
LOWS FROM DROPPING TO STATISTICAL GUIDANCE LOWS. EXPECT LOWS
OVERNIGHT TO RANGE FROM THE MID 50S IN THE NORTHWEST TO THE UPPER
50S ELSEWHERE.
SATURDAY APPEARS TO BE ANOTHER STELLAR FALL LIKE DAY... AFTER THE
LOW STRATUS LIFTS... WHICH WILL BE MORE PREVALENT FROM RALEIGH
EASTWARD. WINDS SHOULD BE A BIT WEAKER FOR SATURDAY... AS A PIECE OF
THE RIDGE AXIS BREAKS OFF AND TRANSLATED TO A BAGGY HIGH OVER THE
MID ATLANTIC REGION. THUS... SLACKING THE GRADIENT A BIT AROSE
CENTRAL NC. SKIES AGAIN ARE EXPECTED TO BE PARTLY SUNNY ACROSS THE
AREA... WITH AFTERNOON HIGHS IN THE MID TO UPPER 70S. -BSD
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 230 PM FRIDAY...
SATURDAY NIGHT AND SUNDAY:
THIS PORTION OF THE FCST WILL BE CHARACTERIZED BY WEAK SURFACE HIGH
PRESSURE REMAINING OVER THE MID-ATLANTIC AND CAROLINAS...WITH A WEAK
LOW OR BROAD/ELONGATED SURFACE TROUGH OFF THE SOUTHEAST/MID-ATLANTIC
COAST. ALOFT...BOTH THE GFS/NAM SHOW WEAK TROUGHING JUST WEST OF THE
APPALACHIANS OVER THE DEEP SOUTH AND TN VALLEY...WITH RIDGING ALOFT
OVER THE OH VALLEY INTO THE UPPER GREAT LAKES. NOT MUCH IN THE WAY
OF LIFT EXPECTED ACROSS CENTRAL NC ON SUNDAY...EXCEPT FOR PERHAPS A
WEAK PERTURBATION IN SW/WSW FLOW ALOFT (DOWNSTREAM OF THE WEAK UPPER
TROUGH TO OUR WEST). EVEN IF THERE ARE ANY WEAK SHORTWAVES IN SW
FLOW ALOFT...FCST SOUNDINGS SHOW AN ATMOSPHERE THAT IS PRETTY
UNSUPPORTIVE OF PRECIPITATION...WITH PWAT VALUES IN THE 0.75-1.00"
RANGE...VERY DRY LOW/MID LEVELS OVER MOST OF THE AREA...AND NO
INSTABILITY. THE BEST MOISTURE AND FORCING FOR PRECIP IS EXPECTED TO
REMAIN OFFSHORE THE CAROLINA/SOUTHEAST COAST. THEREFORE...WILL
CONTINUE TO ADVERTISE A DRY FORECAST THROUGH THIS PERIOD. LOW TEMPS
SUN MORNING COULD BE TRICKY AS THE MAV MOS GUIDANCE IS AS MUCH AS
5-10F WARMER THAN THE MET MOS GUIDANCE...WITH THE PRIMARY DIFFERENCE
DUE TO DIFFERENCES IN LOW LEVEL CLOUD COVER DURING THE EARLY MORNING
HOURS. AT THIS TIME WILL GO WITH A BLEND...ADVERTISING LOWS SUN
MORNING IN THE MID/UPPER 50S. BASED ON MORNING/AFTERNOON THICKNESSES
(1375/1390M)...HIGH TEMPS SHOULD RANGE FROM THE UPPER 70S TO NEAR
80F...LOWEST NW AND HIGHEST SE.
SUNDAY NIGHT THROUGH MONDAY NIGHT:
SFC HIGH PRESSURE IS EXPECTED TO STRENGTHEN OVER SOUTHEAST CANADA
AND NEW ENGLAND ON SUN NIGHT AND MONDAY...WITH THE PRESSURE GRADIENT
ACROSS THE CAROLINAS AND MID-ATLANTIC INCREASING THROUGHOUT THE DAY
AS THE ASSOCIATED INVERTED RIDGE AXIS STRENGTHENS AND EXTENDS DOWN
THE LEE OF THE APPALACHIANS. A WEAK/BROAD SFC TROUGH IS EXPECTED TO
REMAIN OFFSHORE THE SE COAST. ALOFT...THE WEAK UPPER TROUGH WEST OF
THE MOUNTAINS IN THE DEEP SOUTH AND TN VALLEY IS EXPECTED TO MOVE A
BIT CLOSER TO THE CAROLINAS. WILL CONTINUE TO SHOW A DRY FCST WITH
LITTLE IN THE WAY OF LIFT (WEAK PERTURBATIONS ALOFT POSSIBLE).
AGAIN... THE BEST MOISTURE/FORCING SHOULD REMAIN OFF THE SE COAST.
FCST SOUNDINGS SHOW NORTHEAST FLOW IN THE MIXED LAYER INCREASING TO
15-20 KNOTS BY 21Z...AND WILL SHOW SUSTAINED NORTHEAST WINDS AT
10-15 MPH WITH GUSTS UP TO 20 MPH...PRIMARILY IN THE EASTERN HALF OF
THE AREA WHERE THE GRADIENT WILL BE TIGHTER. LOW TEMPS MON MORNING
SIMILAR BUT SLIGHTLY WARMER THAN SUN MORNING...IN THE MID/UPPER 50S.
HIGH TEMPS ON MONDAY MAY VERY WELL BE THE WARMEST OF THE WEEK...
WITH THICKNESSES SUGGESTING UPPER 70S TO LOWER 80S (78-81F). LOW
TEMPS TUE MORNING IN THE UPPER 50S TO LOWER 60S. -VINCENT
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 PM FRIDAY...
MOST OF THE EXTENDED PERIOD CONTINUES TO LOOK DRY...WITH PRONOUNCED
SFC RIDGING ASSOC/W HIGH PRESSURE IN NEW ENGLAND (OR JUST OFF THE
NEW ENGLAND COAST) EXTENDING SOUTH THROUGH THE MID-ATLANTIC INTO THE
CAROLINAS. NO MOIST/OVERRUNNING FLOW IS EXPECTED BASED ON THE LATEST
GFS/ECMWF RUNS...SO THIS SHOULD BE A DRY SFC RIDGE AXIS IN CONTRAST
TO A WEDGE/CAD SETUP. UNCERTAINTY INCREASES BY LATE WEEK AS THE
GFS/ECMWF ARE OFFERING DIFFERENT SOLUTIONS W/RESPECT TO A POTENTIAL
LOW PRESSURE SYSTEM DEVELOPING OFF THE SOUTHEAST COAST. ALTHOUGH WE
WILL NEED TO KEEP AN EYE OUT FOR THE POSSIBILITY OF A DEEP LOW
PRESSURE SYSTEM DEVELOPING OFF THE SOUTHEAST COAST BY THU/FRI...AT
THIS TIME CONFIDENCE IS JUST TOO LOW TO REFLECT MUCH OF A CHANGE IN
THE FCST BY THE END OF THE WEEK...AND WILL CONTINUE TO BASE THE FCST
ON A PATTERN OF SFC RIDGING EXTENDING INTO THE AREA FROM THE
NORTH...AND A WEAK AREA OF LOW PRESSURE WELL OFFSHORE. THIS YIELDS
HIGH TEMPS GENERALLY IN THE MID TO UPPER 70S...WITH LOWS IN THE
MID/UPPER 50S. -VINCENT
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 130 PM FRIDAY...
A PERSISTENT LOW LEVEL NORTHEASTERLY FLOW WILL CONTINUE TO ALLOW LOW
LEVEL MOISTURE TO STREAM INTO THE REGION FROM OFF THE ATLANTIC
THROUGH AT LEAST SATURDAY... AS HIGH PRESSURE EXTENDS INTO THE MID
ATLANTIC REGION FROM THE NEW ENGLAND AREA. THIS WILL RESULT IN
SCATTERED TO BROKEN CLOUD COVER THIS AFTERNOON ACROSS THE AREA...
WITH CLOUD BASES EXPECTED TO RANGE FROM 3500FT TO 5000FT. WINDS WILL
REMAIN GUSTY ACROSS THE AREA THROUGH SUNSET AS THE PRESSURE GRADIENT
ACROSS THE AREA REMAINS TIGHT. AFTER MIXING ENDS WITH THE SETTING OF
THE SUN... STILL EXPECTED WINDS FROM RALEIGH EASTWARD TO REMAIN
BETWEEN 6 TO 10 KTS... WITH WINDS A BIT WEAKER AT KINT AND KGSO...
AS THESE SITES ARE CLOSER TO THE RIDGE AXIS. LOW LEVEL WIND SHEAR
WILL BE POSSIBLE AGAIN OVERNIGHT TOWARDS SUNRISE AS WINDS BETWEEN
ONE TO TWO THOUSAND FEET OFF THE GROUND WILL BE NEAR 25 KTS AT
KRDU... KFAY... AND KRWI. HOWEVER... WITH WINDS AT THE SURFACE
PROGGED TO BE A BIT STRONGER THIS MORNING WILL LEAVE MENTION OF LLWS
OUT OF THE TAFS FOR NOW. HOWEVER... LATER SHIFT WILL NEED TO MONITOR
THE POTENTIAL FOR LLWS.
LOW STRATUS LOOKS TO BE ON TAP AGAIN FOR TOMORROW MORNING... AS 925
MB MOISTURE INCREASES OVERNIGHT IN THE PERSISTENT NORTHEASTERLY
FLOW. THUS... EXPECT IFR... POSSIBLY LIFR... AT KRDU... KRWI... AND
KFAY. KGSO AND KINT SHOULD NOT SEE AS MUCH STRATUS DUE IN PART TO
THEIR PROXIMITY TO THE RIDGE AXIS. THUS... WILL ONLY MENTION MVFR
CEILINGS AND VISIBILITIES AT THIS TIME.
THE LOW CLOUDS WILL LIKELY BE SLOW TO LIFT AGAIN ON SATURDAY...
BEFORE MORPHING INTO STRATOCUMULUS. RESTRICTED CEILINGS AT KRDU...
KFAY... AND KRWI MAY TAKE MOST OF THE MORNING TO LIFT TO VFR. WINDS
ON SATURDAY SHOULD BE LIGHTER AS THE AREA OF SURFACE HIGH
PRESSURE... CURRENTLY LOCATED OVER NEW ENGLAND... MOVES OFF TO THE
NORTHWEST. THIS WILL ALLOW THE A PIECE OF THE SURFACE RIDGE TO BREAK
OFF AND ALLOW A BAGGY HIGH TO FORM OVER THE MID ATLANTIC REGION.
MEANWHILE AND AREA OF LOW PRESSURE WILL REMAIN OFF THE MID ATLANTIC
COAST. THIS ALL WILL LEAD TO WINDS BE A BIT LIGHTER FOR SATURDAY...
GENERALLY RANGING FROM 7 TO 11 KTS ACROSS THE AREA... WITH GUST FROM
15 TO 18 KTS POSSIBLE.
BEYOND 18Z SATURDAY... GENERAL VFR CONDITIONS WILL PERSIST THROUGH
MIDWEEK WITH HIGH PRESSURE RIDGING IN FROM THE NORTH. HOWEVER...
PERSISTENT NORTHEASTERLY FLOW WILL LIKELY BRING IN PERIODS OF
CLOUDINESS... POTENTIALLY IN THE MVFR CATEGORY AT TIMES.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BSD
NEAR TERM...BSD
SHORT TERM...VINCENT
LONG TERM...VINCENT
AVIATION...BSD
000
FXUS62 KRAH 191847
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
247 PM EDT FRI SEP 19 2008
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL EXTEND INTO THE MID ATLANTIC REGION
THROUGH THE WEEKEND...BRINGING COOL AND DRY CONDITIONS TO CENTRAL
NORTH CAROLINA.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 245 PM FRIDAY...
HIGH PRESSURE LOCATED OVER NEW ENGLAND WILL CONTINUES TO RIDGE DOWN
THE EASTERN SEABOARD THE REST OF THIS AFTERNOON INTO TONIGHT. THIS
WILL YIELD ANOTHER PLEASANT DRY EARLY FALL LIKE AFTERNOON ACROSS
CENTRAL NORTH CAROLINA. WINDS WILL BE A BIT GUSTY OUT OF THE
NORTHEAST THIS AFTERNOON AS THE PRESSURE GRADIENT REMAINS TIGHT..
AND COUPLED WITH STRONGER WINDS ALOFT MIXING DOWN TO THE SURFACE.
EXPECT WINDS TO GENERALLY BE BETWEEN 10 TO 15 MPH... WITH GUST AS
HIGH AS 25 MPH... ESPECIALLY IN THE COASTAL PLAIN WHERE THE PRESSURE
GRADIENT WILL BE THE TIGHTEST.
FOR TONIGHT CLOUDS WILL BEGIN TO DISSIPATE WITH LACK OF DAYTIME
HEATING. HOWEVER... EXPECT LOW STRATUS TO FORM AFTER MIDNIGHT AS
BOTH THE NAM AND THE GFS DEPICT A SLUG OF MOISTURE ADVECTING IN OFF
OF THE ATLANTIC IN THE LOW LEVELS OF THE ATMOSPHERE WITH THE
NORTHEAST FLOW. THE CLOUD COVER OVERNIGHT SHOULD PREVENT OVERNIGHT
LOWS FROM DROPPING TO STATISTICAL GUIDANCE LOWS. EXPECT LOWS
OVERNIGHT TO RANGE FROM THE MID 50S IN THE NORTHWEST TO THE UPPER
50S ELSEWHERE.
SATURDAY APPEARS TO BE ANOTHER STELLAR FALL LIKE DAY... AFTER THE
LOW STRATUS LIFTS... WHICH WILL BE MORE PREVALENT FROM RALEIGH
EASTWARD. WINDS SHOULD BE A BIT WEAKER FOR SATURDAY... AS A PIECE OF
THE RIDGE AXIS BREAKS OFF AND TRANSLATED TO A BAGGY HIGH OVER THE
MID ATLANTIC REGION. THUS... SLACKING THE GRADIENT A BIT AROSE
CENTRAL NC. SKIES AGAIN ARE EXPECTED TO BE PARTLY SUNNY ACROSS THE
AREA... WITH AFTERNOON HIGHS IN THE MID TO UPPER 70S. -BSD
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 230 PM FRIDAY...
SATURDAY NIGHT AND SUNDAY:
THIS PORTION OF THE FCST WILL BE CHARACTERIZED BY WEAK SURFACE HIGH
PRESSURE REMAINING OVER THE MID-ATLANTIC AND CAROLINAS...WITH A WEAK
LOW OR BROAD/ELONGATED SURFACE TROUGH OFF THE SOUTHEAST/MID-ATLANTIC
COAST. ALOFT...BOTH THE GFS/NAM SHOW WEAK TROUGHING JUST WEST OF THE
APPALACHIANS OVER THE DEEP SOUTH AND TN VALLEY...WITH RIDGING ALOFT
OVER THE OH VALLEY INTO THE UPPER GREAT LAKES. NOT MUCH IN THE WAY
OF LIFT EXPECTED ACROSS CENTRAL NC ON SUNDAY...EXCEPT FOR PERHAPS A
WEAK PERTURBATION IN SW/WSW FLOW ALOFT (DOWNSTREAM OF THE WEAK UPPER
TROUGH TO OUR WEST). EVEN IF THERE ARE ANY WEAK SHORTWAVES IN SW
FLOW ALOFT...FCST SOUNDINGS SHOW AN ATMOSPHERE THAT IS PRETTY
UNSUPPORTIVE OF PRECIPITATION...WITH PWAT VALUES IN THE 0.75-1.00"
RANGE...VERY DRY LOW/MID LEVELS OVER MOST OF THE AREA...AND NO
INSTABILITY. THE BEST MOISTURE AND FORCING FOR PRECIP IS EXPECTED TO
REMAIN OFFSHORE THE CAROLINA/SOUTHEAST COAST. THEREFORE...WILL
CONTINUE TO ADVERTISE A DRY FORECAST THROUGH THIS PERIOD. LOW TEMPS
SUN MORNING COULD BE TRICKY AS THE MAV MOS GUIDANCE IS AS MUCH AS
5-10F WARMER THAN THE MET MOS GUIDANCE...WITH THE PRIMARY DIFFERENCE
DUE TO DIFFERENCES IN LOW LEVEL CLOUD COVER DURING THE EARLY MORNING
HOURS. AT THIS TIME WILL GO WITH A BLEND...ADVERTISING LOWS SUN
MORNING IN THE MID/UPPER 50S. BASED ON MORNING/AFTERNOON THICKNESSES
(1375/1390M)...HIGH TEMPS SHOULD RANGE FROM THE UPPER 70S TO NEAR
80F...LOWEST NW AND HIGHEST SE.
SUNDAY NIGHT THROUGH MONDAY NIGHT:
SFC HIGH PRESSURE IS EXPECTED TO STRENGTHEN OVER SOUTHEAST CANADA
AND NEW ENGLAND ON SUN NIGHT AND MONDAY...WITH THE PRESSURE GRADIENT
ACROSS THE CAROLINAS AND MID-ATLANTIC INCREASING THROUGHOUT THE DAY
AS THE ASSOCIATED INVERTED RIDGE AXIS STRENGTHENS AND EXTENDS DOWN
THE LEE OF THE APPALACHIANS. A WEAK/BROAD SFC TROUGH IS EXPECTED TO
REMAIN OFFSHORE THE SE COAST. ALOFT...THE WEAK UPPER TROUGH WEST OF
THE MOUNTAINS IN THE DEEP SOUTH AND TN VALLEY IS EXPECTED TO MOVE A
BIT CLOSER TO THE CAROLINAS. WILL CONTINUE TO SHOW A DRY FCST WITH
LITTLE IN THE WAY OF LIFT (WEAK PERTURBATIONS ALOFT POSSIBLE).
AGAIN... THE BEST MOISTURE/FORCING SHOULD REMAIN OFF THE SE COAST.
FCST SOUNDINGS SHOW NORTHEAST FLOW IN THE MIXED LAYER INCREASING TO
15-20 KNOTS BY 21Z...AND WILL SHOW SUSTAINED NORTHEAST WINDS AT
10-15 MPH WITH GUSTS UP TO 20 MPH...PRIMARILY IN THE EASTERN HALF OF
THE AREA WHERE THE GRADIENT WILL BE TIGHTER. LOW TEMPS MON MORNING
SIMILAR BUT SLIGHTLY WARMER THAN SUN MORNING...IN THE MID/UPPER 50S.
HIGH TEMPS ON MONDAY MAY VERY WELL BE THE WARMEST OF THE WEEK...
WITH THICKNESSES SUGGESTING UPPER 70S TO LOWER 80S (78-81F). LOW
TEMPS TUE MORNING IN THE UPPER 50S TO LOWER 60S. -VINCENT
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM FRIDAY...
ANOTHER COOL HIGH PRESSURE AREA WILL BUILD SOUTH ACROSS THE AREA
FROM EASTERN CANADA. IT WILL MAINTAIN ITS PRESENCE AND NORTHEAST
FLOW THROUGH THE PERIOD. THE MAIN CHANGE WILL BE A RETURN TO COOLER
TEMPERATURES AFTER MONDAY WITH HIGH GENERALLY IN THE MID TO UPPER
70S. LOWS WILL BE IN THE 50S. A DRY FORECAST WILL BE MAINTAINED...
HOWEVER VARYING AMOUNTS OF CLOUDS WILL PREVAIL THROUGH THE PERIOD AS
A LOW PRESSURE SYSTEM OFFSHORE ENHANCES NORTHEAST FLOW ESPECIALLY
OVER THE EAST.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 130 PM FRIDAY...
A PERSISTENT LOW LEVEL NORTHEASTERLY FLOW WILL CONTINUE TO ALLOW LOW
LEVEL MOISTURE TO STREAM INTO THE REGION FROM OFF THE ATLANTIC
THROUGH AT LEAST SATURDAY... AS HIGH PRESSURE EXTENDS INTO THE MID
ATLANTIC REGION FROM THE NEW ENGLAND AREA. THIS WILL RESULT IN
SCATTERED TO BROKEN CLOUD COVER THIS AFTERNOON ACROSS THE AREA...
WITH CLOUD BASES EXPECTED TO RANGE FROM 3500FT TO 5000FT. WINDS WILL
REMAIN GUSTY ACROSS THE AREA THROUGH SUNSET AS THE PRESSURE GRADIENT
ACROSS THE AREA REMAINS TIGHT. AFTER MIXING ENDS WITH THE SETTING OF
THE SUN... STILL EXPECTED WINDS FROM RALEIGH EASTWARD TO REMAIN
BETWEEN 6 TO 10 KTS... WITH WINDS A BIT WEAKER AT KINT AND KGSO...
AS THESE SITES ARE CLOSER TO THE RIDGE AXIS. LOW LEVEL WIND SHEAR
WILL BE POSSIBLE AGAIN OVERNIGHT TOWARDS SUNRISE AS WINDS BETWEEN
ONE TO TWO THOUSAND FEET OFF THE GROUND WILL BE NEAR 25 KTS AT
KRDU... KFAY... AND KRWI. HOWEVER... WITH WINDS AT THE SURFACE
PROGGED TO BE A BIT STRONGER THIS MORNING WILL LEAVE MENTION OF LLWS
OUT OF THE TAFS FOR NOW. HOWEVER... LATER SHIFT WILL NEED TO MONITOR
THE POTENTIAL FOR LLWS.
LOW STRATUS LOOKS TO BE ON TAP AGAIN FOR TOMORROW MORNING... AS 925
MB MOISTURE INCREASES OVERNIGHT IN THE PERSISTENT NORTHEASTERLY
FLOW. THUS... EXPECT IFR... POSSIBLY LIFR... AT KRDU... KRWI... AND
KFAY. KGSO AND KINT SHOULD NOT SEE AS MUCH STRATUS DUE IN PART TO
THEIR PROXIMITY TO THE RIDGE AXIS. THUS... WILL ONLY MENTION MVFR
CEILINGS AND VISIBILITIES AT THIS TIME.
THE LOW CLOUDS WILL LIKELY BE SLOW TO LIFT AGAIN ON SATURDAY...
BEFORE MORPHING INTO STRATOCUMULUS. RESTRICTED CEILINGS AT KRDU...
KFAY... AND KRWI MAY TAKE MOST OF THE MORNING TO LIFT TO VFR. WINDS
ON SATURDAY SHOULD BE LIGHTER AS THE AREA OF SURFACE HIGH
PRESSURE... CURRENTLY LOCATED OVER NEW ENGLAND... MOVES OFF TO THE
NORTHWEST. THIS WILL ALLOW THE A PIECE OF THE SURFACE RIDGE TO BREAK
OFF AND ALLOW A BAGGY HIGH TO FORM OVER THE MID ATLANTIC REGION.
MEANWHILE AND AREA OF LOW PRESSURE WILL REMAIN OFF THE MID ATLANTIC
COAST. THIS ALL WILL LEAD TO WINDS BE A BIT LIGHTER FOR SATURDAY...
GENERALLY RANGING FROM 7 TO 11 KTS ACROSS THE AREA... WITH GUST FROM
15 TO 18 KTS POSSIBLE.
BEYOND 18Z SATURDAY... GENERAL VFR CONDITIONS WILL PERSIST THROUGH
MIDWEEK WITH HIGH PRESSURE RIDGING IN FROM THE NORTH. HOWEVER...
PERSISTENT NORTHEASTERLY FLOW WILL LIKELY BRING IN PERIODS OF
CLOUDINESS... POTENTIALLY IN THE MVFR CATEGORY AT TIMES.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BSD
NEAR TERM...BSD
SHORT TERM...VINCENT
LONG TERM...RHJ
AVIATION...BSD
000
FXUS62 KILM 191752
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
153 PM EDT FRI SEP 19 2008
.SYNOPSIS...
HIGH PRESSURE ACROSS THE NORTHEAST WILL RIDGE INTO THE CAROLINAS
THROUGH THE WEEKEND AND BRING COOLER THAN NORMAL TEMPERATURES TO THE
REGION. A TROUGH OF LOW PRESSURE WILL DEVELOP OFFSHORE AND MOVE JUST
CLOSE ENOUGH TO THE AREA TO INCREASE THE CHANCE OF SHOWERS LATE IN
THE WEEKEND AND INTO EARLY NEXT WEEK...MAINLY ALONG THE COASTAL
COUNTIES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 9 AM FRIDAY...BREEZY NORTHEAST WINDS THIS AFTERNOON ARE THE
RESULT OF A PRESSURE GRADIENT BETWEEN A HIGH CENTERED OVER MAINE AND
A FRONTAL BOUNDARY WELL OFF THE COAST. ANOTHER RAIN FREE DAY OVER
LAND IS FORECAST AS MOISTURE CONTINUES TO BE LIMITED. MORNING
SOUNDINGS ALSO SHOW AN INVERSION AROUND 825 MB FROM THE HIGH PRESSURE
RIDGE. THIS IS CONFIRMED BY THE 12 UTC RUC WHICH SHOWS AROUND 90
PERCENT OF THE AREA BEING STABLE. THE ONLY AREA THAT SHOWS ANY
INSTABILITY THIS AFTERNOON BEING EASTERN BRUNSWICK AND NEW HANOVER
COUNTY. WITH THE CAP AT 825 MB DO NOT EXPECT ANY PRECIPITATION OVER
THIS AREA THIS AFTERNOON JUST SOME CONVECTIVE ROLES.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...STILL EXPECTING A COOL AND RELATIVELY DRY
WEEKEND AS HIGH PRESSURE ANCHORED TO THE NORTH AND AN OLD FRONT AND
LOW PRESSURE TO THE EAST WILL BE THE MAIN PLAYERS. THE GFS HAS
TRENDED A LITTLE DRIER WITH THE QPF...WHICH WASNT OVERLY IMPRESSIVE
IN THE FIRST PLACE AS THE SHIELD HAS JOGGED TO THE EAST. THE FLOW
HAS BACKED TO A MORE NORTHERLY DIRECTION AS WELL PROBABLY DUE TO A
WEAK CLOSED CIRCULATION DEVELOPING OVER THE GULF STREAM. ALL OF THIS
SAID...HAVE TRIMMED POPS BACK EVER SO SLIGHTLY TO REPRESENT THIS
TREND...MAINLY CONFINING THEM TO THE COASTAL COUNTIES WITH THE
EXCEPTION OF LATE SATURDAY INTO SUNDAY MORNING WHEN A FEW SPRINKLES
COULD MIGRATE INLAND.
SOME SIGNIFICANT DIFFERENCES REGARDING THE TEMPERATURE GUIDANCE FOR
THE PERIOD WITH THE MET NUMBERS A CATEGORY COOLER IN SOME INSTANCES.
A FEW WEEKS AGO DURING THE HEAT OF THE SUMMER THE SOLUTION WOULD BE
SIMPLE...GO WITH THE MET. WITH THE FALL QUICKLY APPROACHING AND THE
FACT THE MAV NUMBERS HAVE BEEN BETTER AT LEAST DURING THE INITIAL
STAGES OF THIS AIR MASS THE SOLUTION IS A BIT MORE COMPLEX. WILL
UNDERCUT THE MAV NUMBERS A DEGREE OR TWO AS THE MET NUMBERS JUST
SEEM TOO COOL.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...STILL A LOT OF UNCERTAINTY REGARDING THE POSSIBLE
DEVELOPMENT OF LOW PRESSURE OFF THE COAST WHICH WILL BE THE FOCUS
OF THE EXTENDED OR MORE SPECIFICALLY THE LATTER HALF OF THE
EXTENDED...FROM WEDNESDAY ON. THE LATEST OPERATIONAL GFS HAS
SHIFTED THE LOW PRESSURE TO THE SOUTH AND EAST. THE ENSEMBLE
MEMBERS SEEM TO HAVE SOMETHING FOR EVERYONE...WITH LOW PRESSURE
FROM THE BAHAMAS ALL THE WAY TO THE NORTH JUST EAST OF HATTERAS.
OBVIOUSLY THERE IS STILL NOTHING TO HANG OUR HATS ON AND I SUSPECT
IT WILL REMAIN SO FOR THE NEXT FEW DAYS. I TRIMMED BACK POPS AND
CLOUD COVER SLIGHTLY TO REPRESENT A TREND IF NOTHING ELSE BUT
CONFIDENCE IN LOWER THAN USUAL IN THE EXTENDED.
&&
.AVIATION /18Z FRIDAY THROUGH TUESDAY/...
AVIATION PROBLEMS WILL BE WITH GUSTING WINDS AT THE COASTAL TAFS
WITH GUST EXPECTED TO REACH AROUND 25 KNOTS TONIGHT . ALSO...MODELS
ARE INDICATING LIFR/IFR STRATUS ALONG THE COAST AFTER 09 UTC. BUFR
SOUNDINGS ARE SHOWING STRATUS LAYER A BIT HIGHER IN THE MVFR RANGE
AT THE SAME TIME. SO HAVE FAVORED BUFR SOUNDINGS OVER THE NUMERICAL
GUIDANCE.
OUTLOOK THROUGH MONDAY...WITH TROUGH OF LOW PRESSURE AND MODELS
STILL NOT HONING IN ON A SIMILAR SOLUTION THERE CONTINUES TO BE
HIGHER THAN NORMAL UNCERTAINTY IN THIS PERIOD. CONDITIONS WILL
DRIVEN BY THE LOCATION AND TIMING OF THE LOW PRESSURE CENTERS THAT
TRANSVERSE THE OFFSHORE BOUNDARY AND THE DISTANCE TO THE TAFS SITES.
THE INLAND TAF SITES WILL GENERALLY BE VFR WHILE COASTAL SITES HAVE
A BETTER CHANCE OF SEEING SHOWERS AND LOWER CEILING.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF NOON FRIDAY...A TIGHT PRESSURE GRADIENT RESULTING FROM HIGH
PRESSURE OVER MAINE AND AN OLD FRONT OFF THE COAST IS PRODUCING
STRONG NORTHEAST WINDS. AT NOON FRYING PAN WAS REPORTING NORTHEAST
WINDS OF 27 KNOTS AND SEAS OF 8.5 FEET. CLOSE TO THE COAST SEAS 4 TO
5 FEET WERE BEING OBSERVED. AS THE PRESSURE GRADIENT CONTINUE
THROUGH TONIGHT SEAS AND WINDS WILL REMAIN HIGH AND SMALL CRAFT
CONDITIONS WILL CONTINUE INTO SATURDAY.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...A NORTH TO NORTHEAST FLOW WILL PREVAIL THROUGH
THE PERIOD. THE DILEMMA IS WHAT WILL BE THE MAGNITUDE OF THE FLOW AS
THE NAM/WRF IS MUCH STRONGER WITH THE GRADIENT DUE TO THE CLOSED LOW
OVER THE GULF STREAM BEING DEEPER. THERE IS A GOOD 10 TO 12 KNOTS
DIFFERENCE IN THE MARINE GUIDANCE FOR 41013 WHEN COMPARING THE NAM
AND MAV BULLETINS. I LIKE THE GFS BUT CANT DISREGARD THE NAM
COMPLETELY AND WILL INCREASE THE GFS WINDS ANS SEAS A BIT ACROSS THE
BOARD. WITH THIS IN MIND...EXPECT SMALL CRAFT CONDITIONS TO CONTINUE
SATURDAY AND WILL EXTEND THROUGH THE DAY WITH SUFFICIENT CONFIDENCE.
COULD BE A SIMILAR SITUATION SUNDAY AS THE NAM CONTINUES WITH THE
ROBUST SOLUTION. FOR NOW HAVE WINDS AND SEAS DROPPING BELOW FLAG
CRITERIA BUT SUBSEQUENT SHIFTS WILL HAVE TO MONITOR TRENDS CLOSELY.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 AM FRIDAY...NORTHEAST FLOW THROUGH THE PERIOD...MOST LIKELY
BELOW FLAG CRITERIA. NO CHANGES TO THE EXTENDED COASTAL WATERS
FORECAST THIS MORNING.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT SATURDAY FOR AMZ250-252-
254-256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...HAWKINS
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...HAWKINS
000
FXUS62 KRAH 191734
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
133 PM EDT FRI SEP 19 2008
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL EXTEND INTO THE MID ATLANTIC REGION
THROUGH THE WEEKEND...BRINGING COOL AND DRY CONDITIONS TO CENTRAL
NORTH CAROLINA.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1030 AM FRIDAY...
HIGH PRESSURE LOCATED OVER NEW ENGLAND CONTINUES TO RIDGE DOWN THE
EASTERN SEABOARD. THIS WILL YIELD ANOTHER PLEASANT DRY EARLY FALL
LIKE DAY ACROSS CENTRAL NORTH CAROLINA. WINDS WILL BE A BIT GUSTY
OUT OF THE NORTHEAST TODAY AS THE PRESSURE GRADIENT REMAINS TIGHT
AND COUPLED WITH STRONGER WINDS ALOFT MIXING DOWN TO THE SURFACE.
EXPECT WINDS TO GENERALLY BE BETWEEN 10 TO 15 MPH... WITH GUST AS
HIGH AS 25 MPH... ESPECIALLY IN THE COASTAL PLAIN WHERE THE PRESSURE
GRADIENT WILL BE THE TIGHTEST.
CLOUD COVER WILL LIKELY HINDER TEMPERATURES A BIT TODAY... AS A VERY
WEAK SURFACE TO 850 MB BOUNDARY LOCATED OVER SOUTHERN VIRGINIA
PUSHES SOUTH INTO CENTRAL NC. BOTH THE NAM AND GFS BUFR SOUNDINGS
INDICATED THE BEST MOISTURE PROFILE TO BE IN THE NORTHWEST PIEDMONT.
VISIBLE SATELLITE IMAGERY THIS MORNING DEPICTS CLOUDS ALREADY
BEGINNING TO MOVE INTO NORTHERN PORTIONS OF CENTRAL NORTH
CAROLINA... WITH THE THICKEST CLOUDS LOCATED OVER THE NORTHWEST
PIEDMONT. CURRENTLY CLOUD BASE ARE AT OR LESS THAN A THOUSAND FEET
ACROSS NORTHERN PORTIONS OF THE STATE. THE LOW STRATUS THIS MORNING
WILL QUICKLY LIFT TO A STRATOCUMULUS DECK OF CLOUDS. THE CLOUDS
COUPLED WITH 1000-850 MB THICKNESS VALUES ABOUT 10 METERS LESS THAN
YESTERDAY WILL YIELD TEMPERATURES AT BIT COOLER TODAY THAN
YESTERDAY. HOWEVER... TEMPERATURES WILL AGAIN BE PLEASANT TODAY...
WITH HIGHS GENERALLY IN THE MID TO UPPER 70S... EXCEPT IN THE
NORTHWEST WHERE TEMPERATURES ARE GETTING OFF TO A SLOW START THANKS
TO THE THICKEST CLOUD COVER. HIGH TEMPS IN THE NORTHWEST MAY
STRUGGLE TO MAKE IT OUT OF THE LOW 70S TODAY... THANKS IN PART TO
THICK CLOUD COVER MOVING IN FROM SOUTHERN VIRGINIA.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 230 AM FRIDAY...
HIGH PRESSURE CONTINUES TO BUILD DOWN THE COAST FRIDAY NIGHT THROUGH
SATURDAY... HOWEVER THE SYSTEM BECOME QUITE BAGGY SUNDAY AND SUNDAY
NIGHT AS A HIGH CENTER SETTLE OVER NORTHWEST NORTH CAROLINA. VARYING
AMOUNTS OF CLOUD COVER THROUGH THE PERIOD WITH THE HIGHEST
CONCENTRATION ALONG THE COAST IN CONJUNCTION WITH AN OFFSHORE LOW
PRESSURE CENTER. LOWS IN THE MID TO UPPER 50S FRIDAY NIGHT AND
SATURDAY NIGHT AND IN UPPER 50S TO LOWER 60S SOUTHEAST SUNDAY NIGHT.
SLIGHT WARMING TREND THROUGH THE PERIOD...WITH HIGHS IN THE MID TO
UPPER 70S SATURDAY AND UPPER 70S TO AROUND 80 SUNDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 AM FRIDAY...
ANOTHER COOL HIGH PRESSURE AREA WILL BUILD SOUTH ACROSS THE AREA
FROM EASTERN CANADA. IT WILL MAINTAIN ITS PRESENCE AND NORTHEAST
FLOW THROUGH THE PERIOD. THE MAIN CHANGE WILL BE A RETURN TO COOLER
TEMPERATURES AFTER MONDAY WITH HIGH GENERALLY IN THE MID TO UPPER
70S. LOWS WILL BE IN THE 50S. A DRY FORECAST WILL BE MAINTAINED...
HOWEVER VARYING AMOUNTS OF CLOUDS WILL PREVAIL THROUGH THE PERIOD AS
A LOW PRESSURE SYSTEM OFFSHORE ENHANCES NORTHEAST FLOW ESPECIALLY
OVER THE EAST.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 130 PM FRIDAY...
A PERSISTENT LOW LEVEL NORTHEASTERLY FLOW WILL CONTINUE TO ALLOW LOW
LEVEL MOISTURE TO STREAM INTO THE REGION FROM OFF THE ATLANTIC
THROUGH AT LEAST SATURDAY... AS HIGH PRESSURE EXTENDS INTO THE MID
ATLANTIC REGION FROM THE NEW ENGLAND AREA. THIS WILL RESULT IN
SCATTERED TO BROKEN CLOUD COVER THIS AFTERNOON ACROSS THE AREA...
WITH CLOUD BASES EXPECTED TO RANGE FROM 3500FT TO 5000FT. WINDS WILL
REMAIN GUSTY ACROSS THE AREA THROUGH SUNSET AS THE PRESSURE GRADIENT
ACROSS THE AREA REMAINS TIGHT. AFTER MIXING ENDS WITH THE SETTING OF
THE SUN... STILL EXPECTED WINDS FROM RALEIGH EASTWARD TO REMAIN
BETWEEN 6 TO 10 KTS... WITH WINDS A BIT WEAKER AT KINT AND KGSO...
AS THESE SITES ARE CLOSER TO THE RIDGE AXIS. LOW LEVEL WIND SHEAR
WILL BE POSSIBLE AGAIN OVERNIGHT TOWARDS SUNRISE AS WINDS BETWEEN
ONE TO TWO THOUSAND FEET OFF THE GROUND WILL BE NEAR 25 KTS AT
KRDU... KFAY... AND KRWI. HOWEVER... WITH WINDS AT THE SURFACE
PROGGED TO BE A BIT STRONGER THIS MORNING WILL LEAVE MENTION OF LLWS
OUT OF THE TAFS FOR NOW. HOWEVER... LATER SHIFT WILL NEED TO MONITOR
THE POTENTIAL FOR LLWS.
LOW STRATUS LOOKS TO BE ON TAP AGAIN FOR TOMORROW MORNING... AS 925
MB MOISTURE INCREASES OVERNIGHT IN THE PERSISTENT NORTHEASTERLY
FLOW. THUS... EXPECT IFR... POSSIBLY LIFR... AT KRDU... KRWI... AND
KFAY. KGSO AND KINT SHOULD NOT SEE AS MUCH STRATUS DUE IN PART TO
THEIR PROXIMITY TO THE RIDGE AXIS. THUS... WILL ONLY MENTION MVFR
CEILINGS AND VISIBILITIES AT THIS TIME.
THE LOW CLOUDS WILL LIKELY BE SLOW TO LIFT AGAIN ON SATURDAY...
BEFORE MORPHING INTO STRATOCUMULUS. RESTRICTED CEILINGS AT KRDU...
KFAY... AND KRWI MAY TAKE MOST OF THE MORNING TO LIFT TO VFR. WINDS
ON SATURDAY SHOULD BE LIGHTER AS THE AREA OF SURFACE HIGH
PRESSURE... CURRENTLY LOCATED OVER NEW ENGLAND... MOVES OFF TO THE
NORTHWEST. THIS WILL ALLOW THE A PIECE OF THE SURFACE RIDGE TO BREAK
OFF AND ALLOW A BAGGY HIGH TO FORM OVER THE MID ATLANTIC REGION.
MEANWHILE AND AREA OF LOW PRESSURE WILL REMAIN OFF THE MID ATLANTIC
COAST. THIS ALL WILL LEAD TO WINDS BE A BIT LIGHTER FOR SATURDAY...
GENERALLY RANGING FROM 7 TO 11 KTS ACROSS THE AREA... WITH GUST FROM
15 TO 18 KTS POSSIBLE.
BEYOND 18Z SATURDAY... GENERAL VFR CONDITIONS WILL PERSIST THROUGH
MIDWEEK WITH HIGH PRESSURE RIDGING IN FROM THE NORTH. HOWEVER...
PERSISTENT NORTHEASTERLY FLOW WILL LIKELY BRING IN PERIODS OF
CLOUDINESS... POTENTIALLY IN THE MVFR CATEGORY AT TIMES.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BSD
NEAR TERM...BSD
SHORT TERM...RHJ
LONG TERM...RHJ
AVIATION...BSD
000
FXUS62 KILM 191626
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1230 PM EDT FRI SEP 19 2008
.SYNOPSIS...
HIGH PRESSURE ACROSS THE NORTHEAST WILL RIDGE INTO THE CAROLINAS
THROUGH THE WEEKEND AND BRING COOLER THAN NORMAL TEMPERATURES TO THE
REGION. A TROUGH OF LOW PRESSURE WILL DEVELOP OFFSHORE AND MOVE JUST
CLOSE ENOUGH TO THE AREA TO INCREASE THE CHANCE OF SHOWERS LATE IN
THE WEEKEND AND INTO EARLY NEXT WEEK...MAINLY ALONG THE COASTAL
COUNTIES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 9 AM FRIDAY...BREEZY NORTHEAST WINDS THIS AFTERNOON ARE THE
RESULT OF A PRESSURE GRADIENT BETWEEN A HIGH CENTERED OVER MAINE AND
A FRONTAL BOUNDARY WELL OFF THE COAST. ANOTHER RAIN FREE DAY OVER
LAND IS FORECAST AS MOISTURE CONTINUES TO BE LIMITED. MORNING
SOUNDINGS ALSO SHOW AN INVERSION AROUND 825 MB FROM THE HIGH PRESSURE
RIDGE. THIS IS CONFIRMED BY THE 12 UTC RUC WHICH SHOWS AROUND 90
PERCENT OF THE AREA BEING STABLE. THE ONLY AREA THAT SHOWS ANY
INSTABILITY THIS AFTERNOON BEING EASTERN BRUNSWICK AND NEW HANOVER
COUNTY. WITH THE CAP AT 825 MB DO NOT EXPECT ANY PRECIPITATION OVER
THIS AREA THIS AFTERNOON JUST SOME CONVECTIVE ROLES.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...STILL EXPECTING A COOL AND RELATIVELY DRY
WEEKEND AS HIGH PRESSURE ANCHORED TO THE NORTH AND AN OLD FRONT AND
LOW PRESSURE TO THE EAST WILL BE THE MAIN PLAYERS. THE GFS HAS
TRENDED A LITTLE DRIER WITH THE QPF...WHICH WASNT OVERLY IMPRESSIVE
IN THE FIRST PLACE AS THE SHIELD HAS JOGGED TO THE EAST. THE FLOW
HAS BACKED TO A MORE NORTHERLY DIRECTION AS WELL PROBABLY DUE TO A
WEAK CLOSED CIRCULATION DEVELOPING OVER THE GULF STREAM. ALL OF THIS
SAID...HAVE TRIMMED POPS BACK EVER SO SLIGHTLY TO REPRESENT THIS
TREND...MAINLY CONFINING THEM TO THE COASTAL COUNTIES WITH THE
EXCEPTION OF LATE SATURDAY INTO SUNDAY MORNING WHEN A FEW SPRINKLES
COULD MIGRATE INLAND.
SOME SIGNIFICANT DIFFERENCES REGARDING THE TEMPERATURE GUIDANCE FOR
THE PERIOD WITH THE MET NUMBERS A CATEGORY COOLER IN SOME INSTANCES.
A FEW WEEKS AGO DURING THE HEAT OF THE SUMMER THE SOLUTION WOULD BE
SIMPLE...GO WITH THE MET. WITH THE FALL QUICKLY APPROACHING AND THE
FACT THE MAV NUMBERS HAVE BEEN BETTER AT LEAST DURING THE INITIAL
STAGES OF THIS AIR MASS THE SOLUTION IS A BIT MORE COMPLEX. WILL
UNDERCUT THE MAV NUMBERS A DEGREE OR TWO AS THE MET NUMBERS JUST
SEEM TOO COOL.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...STILL A LOT OF UNCERTAINTY REGARDING THE POSSIBLE
DEVELOPMENT OF LOW PRESSURE OFF THE COAST WHICH WILL BE THE FOCUS
OF THE EXTENDED OR MORE SPECIFICALLY THE LATTER HALF OF THE
EXTENDED...FROM WEDNESDAY ON. THE LATEST OPERATIONAL GFS HAS
SHIFTED THE LOW PRESSURE TO THE SOUTH AND EAST. THE ENSEMBLE
MEMBERS SEEM TO HAVE SOMETHING FOR EVERYONE...WITH LOW PRESSURE
FROM THE BAHAMAS ALL THE WAY TO THE NORTH JUST EAST OF HATTERAS.
OBVIOUSLY THERE IS STILL NOTHING TO HANG OUR HATS ON AND I SUSPECT
IT WILL REMAIN SO FOR THE NEXT FEW DAYS. I TRIMMED BACK POPS AND
CLOUD COVER SLIGHTLY TO REPRESENT A TREND IF NOTHING ELSE BUT
CONFIDENCE IN LOWER THAN USUAL IN THE EXTENDED.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS THROUGH THE FORECAST PERIOD. TIGHT GRADIENT TODAY
WILL RESULT IN STRONG BOUNDARY LAYER WINDS ONCE AIRMASS BECOMES
WELL MIXED...A COUPLE OF HOURS AFTER DAYBREAK. FLAT CU DECK
DEVELOP IN THE AFTERNOON BUT CONDITIONS REMAIN VFR. WINDS WILL
DIMINISH SOMEWHAT TOWARD THE END OF THE PERIOD.
OUTLOOK THROUGH MONDAY...QUITE A BIT OF UNCERTAINTY SATURDAY THROUGH
TUESDAY. CONTINUED NORTHEAST FLOW...WITH LOW PRESSURE POSSIBLY
SETTING UP CLOSE ENOUGH TO SHORE TO AFFECT COASTAL TERMINALS WITH
LOWER CEILINGS AND RAIN SATURDAY/SUNDAY. IF THE LOW SETS UP FURTHER
OFFSHORE...LOOK FOR VFR CONDITIONS...HOWEVER WINDY CONDITIONS ARE
EXPECTED SATURDAY...MONDAY AND TUESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF NOON FRIDAY...A TIGHT PRESSURE GRADIENT RESULTING FROM HIGH
PRESSURE OVER MAINE AND AN OLD FRONT OFF THE COAST IS PRODUCING
STRONG NORTHEAST WINDS. AT NOON FRYING PAN WAS REPORTING NORTHEAST
WINDS OF 27 KNOTS AND SEAS OF 8.5 FEET. CLOSE TO THE COAST SEAS 4 TO
5 FEET WERE BEING OBSERVED. AS THE PRESSURE GRADIENT CONTINUE
THROUGH TONIGHT SEAS AND WINDS WILL REMAIN HIGH AND SMALL CRAFT
CONDITIONS WILL CONTINUE INTO SATURDAY.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...A NORTH TO NORTHEAST FLOW WILL PREVAIL THROUGH
THE PERIOD. THE DILEMMA IS WHAT WILL BE THE MAGNITUDE OF THE FLOW AS
THE NAM/WRF IS MUCH STRONGER WITH THE GRADIENT DUE TO THE CLOSED LOW
OVER THE GULF STREAM BEING DEEPER. THERE IS A GOOD 10 TO 12 KNOTS
DIFFERENCE IN THE MARINE GUIDANCE FOR 41013 WHEN COMPARING THE NAM
AND MAV BULLETINS. I LIKE THE GFS BUT CANT DISREGARD THE NAM
COMPLETELY AND WILL INCREASE THE GFS WINDS ANS SEAS A BIT ACROSS THE
BOARD. WITH THIS IN MIND...EXPECT SMALL CRAFT CONDITIONS TO CONTINUE
SATURDAY AND WILL EXTEND THROUGH THE DAY WITH SUFFICIENT CONFIDENCE.
COULD BE A SIMILAR SITUATION SUNDAY AS THE NAM CONTINUES WITH THE
ROBUST SOLUTION. FOR NOW HAVE WINDS AND SEAS DROPPING BELOW FLAG
CRITERIA BUT SUBSEQUENT SHIFTS WILL HAVE TO MONITOR TRENDS CLOSELY.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 AM FRIDAY...NORTHEAST FLOW THROUGH THE PERIOD...MOST LIKELY
BELOW FLAG CRITERIA. NO CHANGES TO THE EXTENDED COASTAL WATERS
FORECAST THIS MORNING.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT SATURDAY FOR AMZ250-252-
254-256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...HAWKINS
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...III
000
FXUS62 KRAH 191456
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1056 AM EDT FRI SEP 19 2008
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL EXTEND INTO THE MID ATLANTIC REGION THROUGH
THE WEEKEND...BRINGING COOL AND DRY CONDITIONS TO CENTRAL NORTH
CAROLINA.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1030 AM FRIDAY...
HIGH PRESSURE LOCATED OVER NEW ENGLAND CONTINUES TO RIDGE DOWN THE
EASTERN SEABOARD. THIS WILL YIELD ANOTHER PLEASANT DRY EARLY FALL
LIKE DAY ACROSS CENTRAL NORTH CAROLINA. WINDS WILL BE A BIT GUSTY
OUT OF THE NORTHEAST TODAY AS THE PRESSURE GRADIENT REMAINS TIGHT
AND COUPLED WITH STRONGER WINDS ALOFT MIXING DOWN TO THE SURFACE.
EXPECT WINDS TO GENERALLY BE BETWEEN 10 TO 15 MPH... WITH GUST AS
HIGH AS 25 MPH... ESPECIALLY IN THE COASTAL PLAIN WHERE THE PRESSURE
GRADIENT WILL BE THE TIGHTEST.
CLOUD COVER WILL LIKELY HINDER TEMPERATURES A BIT TODAY... AS A VERY
WEAK SURFACE TO 850 MB BOUNDARY LOCATED OVER SOUTHERN VIRGINIA
PUSHES SOUTH INTO CENTRAL NC. BOTH THE NAM AND GFS BUFR SOUNDINGS
INDICATED THE BEST MOISTURE PROFILE TO BE IN THE NORTHWEST PIEDMONT.
VISIBLE SATELLITE IMAGERY THIS MORNING DEPICTS CLOUDS ALREADY
BEGINNING TO MOVE INTO NORTHERN PORTIONS OF CENTRAL NORTH
CAROLINA... WITH THE THICKEST CLOUDS LOCATED OVER THE NORTHWEST
PIEDMONT. CURRENTLY CLOUD BASE ARE AT OR LESS THAN A THOUSAND FEET
ACROSS NORTHERN PORTIONS OF THE STATE. THE LOW STRATUS THIS MORNING
WILL QUICKLY LIFT TO A STRATOCUMULUS DECK OF CLOUDS. THE CLOUDS
COUPLED WITH 1000-850 MB THICKNESS VALUES ABOUT 10 METERS LESS THAN
YESTERDAY WILL YIELD TEMPERATURES AT BIT COOLER TODAY THAN
YESTERDAY. HOWEVER... TEMPERATURES WILL AGAIN BE PLEASANT TODAY...
WITH HIGHS GENERALLY IN THE MID TO UPPER 70S... EXCEPT IN THE
NORTHWEST WHERE TEMPERATURES ARE GETTING OFF TO A SLOW START THANKS
TO THE THICKEST CLOUD COVER. HIGH TEMPS IN THE NORTHWEST MAY
STRUGGLE TO MAKE IT OUT OF THE LOW 70S TODAY... THANKS IN PART TO
THICK CLOUD COVER MOVING IN FROM SOUTHERN VIRGINIA.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 230 AM FRIDAY...
HIGH PRESSURE CONTINUES TO BUILD DOWN THE COAST FRIDAY NIGHT THROUGH
SATURDAY... HOWEVER THE SYSTEM BECOME QUITE BAGGY SUNDAY AND SUNDAY
NIGHT AS A HIGH CENTER SETTLE OVER NORTHWEST NORTH CAROLINA. VARYING
AMOUNTS OF CLOUD COVER THROUGH THE PERIOD WITH THE HIGHEST
CONCENTRATION ALONG THE COAST IN CONJUNCTION WITH AN OFFSHORE LOW
PRESSURE CENTER. LOWS IN THE MID TO UPPER 50S FRIDAY NIGHT AND
SATURDAY NIGHT AND IN UPPER 50S TO LOWER 60S SOUTHEAST SUNDAY NIGHT.
SLIGHT WARMING TREND THROUGH THE PERIOD...WITH HIGHS IN THE MID TO
UPPER 70S SATURDAY AND UPPER 70S TO AROUND 80 SUNDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 AM FRIDAY...
ANOTHER COOL HIGH PRESSURE AREA WILL BUILD SOUTH ACROSS THE AREA
FROM EASTERN CANADA. IT WILL MAINTAIN ITS PRESENCE AND NORTHEAST
FLOW THROUGH THE PERIOD. THE MAIN CHANGE WILL BE A RETURN TO COOLER
TEMPERATURES AFTER MONDAY WITH HIGH GENERALLY IN THE MID TO UPPER
70S. LOWS WILL BE IN THE 50S. A DRY FORECAST WILL BE MAINTAINED...
HOWEVER VARYING AMOUNTS OF CLOUDS WILL PREVAIL THROUGH THE PERIOD AS
A LOW PRESSURE SYSTEM OFFSHORE ENHANCES NORTHEAST FLOW ESPECIALLY
OVER THE EAST.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
AS OF 1030 AM FRIDAY...
SUSTAINED WINDS ARE EXPECTED TO BE 10-15 KT ACROSS THE ENTIRE
REGION...WITH GUSTS OF 20 KT OR SLIGHTLY HIGHER AT RDU/FAY/RWI.
WHILE GUSTS WILL DIMINISH CLOSE TO SUNSET...SUSTAINED WINDS WILL
STAY CLOSE TO 10 KT IN THE EAST DUE TO THE PERSISTENT STRONG SFC
PRESSURE GRADIENT. ANOTHER EPISODE OF LLWS POSSIBLE EARLY SATURDAY
MORNING IF SFC WINDS DECREASE SUBSTANTIALLY.
A WEAK SFC-850 MB BOUNDARY LOCATED OVER SOUTHERN VIRGINIA WILL PUSH
FURTHER SOUTH TODAY. BROKEN TO OVERCAST LOW STRATUS HAS MOVED INTO
THE NORTHWEST PIEDMONT... WHILE STRATOCUMULUS HAS DEVELOPED
BEHIND THIS FEATURE OVER OTHER PORTIONS OF CENTRAL NORTH CAROLINA.
IFR/MVFR CIGS ARE EXPECTED AT KINT AND KGSO THROUGH EARLY
AFTERNOON... BEFORE CEILINGS LIFT TO A VFR STRATOCUMULUS DECK OF
CLOUDS. ELSEWHERE POCKETS OF MVFR STRATOCUMULUS WILL QUICKLY LIFT
TO VFR STRATOCUMULUS.
THE BEST MOISTURE PROFILES WILL BE LOCATED OVER THE TRIAD...SO
EXPECTING PERIODS OF BROKEN VFR CIGS DURING THE AFTERNOON HOURS...
WITH CLOUD COVER MORE SCATTERED IN NATURE FURTHER EAST TOWARD RWI.
MODEL GUIDANCE IN GOOD AGREEMENT ON BRINGING IN ANOTHER SURGE OF
LOW LEVEL MOISTURE INTO THE REGION FROM THE EAST OVERNIGHT. WILL
INTRODUCE A LOW END MVFR CIGS AT RWI/FAY/RDU CLOSE TO DAYBREAK
SATURDAY.
GENERAL VFR CONDITIONS WILL PERSIST THROUGH MIDWEEK WITH HIGH
PRESSURE RIDGING IN FROM THE NORTH. HOWEVER...PERSISTENT
NORTHEASTERLY FLOW WILL LIKELY BRING IN PERIODS OF CLOUDINESS...
POTENTIALLY IN THE MVFR CATEGORY AT TIMES.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BSD
NEAR TERM...BSD
SHORT TERM...RHJ
LONG TERM...RHJ
AVIATION...BSD/JFB
000
FXUS62 KMHX 191359
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
959 AM EDT FRI SEP 19 2008
.SYNOPSIS...
STRONG HIGH PRESSURE WILL BUILD INTO THE AREA FROM NEW ENGLAND
TODAY. A WAVE OF LOW PRESSURE WILL MOVE NORTHEAST ALONG A SLOW
MOVING FRONTAL SYSTEM OFF THE SOUTHEAST COAST ON SATURDAY AND
SUNDAY. STRONG HIGH PRESSURE WILL AGAIN BUILD INTO THE AREA FROM
THE NORTH EARLY TO MID NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NICE FALL LIKE DAY ON TAP FOR THE MOST PART THOUGH STIFF NE WINDS
EXPECTED ESPECIALLY ALONG THE COAST...ASSOCIATED WITH A 1036 MB HIGH
OVER VERMONT PER THE 19/12Z NCEP SFC ANALYSIS. 12Z MHX SOUNDING
REVEALED A PWAT OF .88 INCHES WITH EXTREMELY DRY...SUBSIDENT AIR
NOTED OVER THE AREA IN WV IMAGERY ROTATING AROUND AN UPPER TROUGH
AXIS NEAR THE OBX AND RIDGING JUST TO OUR W. ALL OF THE ABOVE SHOULD
KEEP PRECIP AT BAY TODAY WITH PERIODS OF SCU EXPECTED WITH THE NE
FLOW. FORECAST LOOKS ON TRACK SO NOT MANY CHANGES THIS UPDATE...WITH
HIGHS PLEASANT IN THE M-U70S. SEE CFWMHX PRODUCTS AND MARINE
DISCUSSION BELOW FOR INFO ON COASTAL THREATS FROM STRONG NE FLOW.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
MODELS IN GENERAL AGREEMENT ON LIFTING THE DEVELOPING OFFSHORE
SFC WAVE NNE ALONG THE STALLED BNDRY THIS WEEKEND. HOWEVER GFS
APPEARS TO BE THROWING DEEPER MOISTURE (AND SUBSEQUENT PCPN CHCS)
TOO FAR INLAND. WILL LEAN TO A DRYER MODEL CONSENSUS AND KEEP
PCPN CHCS PINNED CLOSER TO THE COAST. A STRAY SHOWER CUD SNEAK IN
FARTHER INLAND AT JUST ABOUT ANYTIME DURING THE WEEKEND BUT EXPECT
MOST ACTIVITY WILL REMAIN RIGHT ALONG THE COAST (AND OFFSHORE) AS
DRYER AIR LIKELY WINS OUT OVER INLAND AREAS. SEASONABLY COOL CONDS
WILL REMAIN ON SATURDAY (HIGHS M-U70S) WITH A STIFF ONSHORE BREEZE
AND SCT/BKN SC CLOUDS. A FEW DEGS MILDER ON SUNDAY (HIGHS U70S/NR
80) AS SFC LOW PULLS FARTHER OFFSHORE ALLOWING ADDITIONAL SUN AND
WEAKER ONSHORE FLOW.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
STRONG SFC HIGH PRES RIDGING IN FROM THE NORTH WILL REINFORCE
OVER THE AREA EARLY TO MID NEXT WEEK FOR MORE MOSUNNY/SEASONABLY
COOL CONDS.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
MAIN CONCERN TODAY IS NE WINDS GUSTING TO AROUND 25 KT OTHERWISE
VFR CONDITIONS WILL OCCUR THROUGH THIS EVENING. THERE IS STILL
SOME UNCERTAINTY ON HOW MUCH MOISTURE FROM A LOW OFF THE COAST
GETS THROWN BACK INLAND ON SATURDAY. AT THE VERY LEAST THERE
IS A POTENTIAL FOR MVFR TO IFR CEILINGS LATE TONIGHT AND
ESPECIALLY FRIDAY. BEST CHANCE FOR ANY RAINFALL WILL AT THE
COASTAL TAF SITES FRIDAY AFTERNOON AND NIGHT.
THE NE FLOW WILL CONTINUE THROUGH THE REST OF THE FORECAST...WITH
IMPROVED CONDITIONS EXPECTED SUN AND MON.
&&
.MARINE...
NO SIGNIFICANT CHANGES TO THE CURRENT FORECAST. THE GRADIENT
BETWEEN STRONG HIGH PRESSURE TO THE NORTH AND WEAK LOW PRESSURE
ALONG A STALLED FRONTAL BOUNDARY TO THE SE WILL PRODUCE STRONG
SMALL CRAFT ADVISORY CONDITIONS (25-30 KT) WITH A FEW GUSTS TO 35
KT. THESE CONDITIONS WILL PERSIST THROUGH TONIGHT WITH SEAS
REACHING 10 FT OR HIGHER.
THE COMBO OF STRONG ONSHORE WINDS...HIGH ASTRO TIDES AND BUILDING
SEAS WILL LEAD TO HIGH SURF ADVRY CONDITIONS FROM HATTERAS NORTH
STARTING 12Z THROUGH SAT MORN. HIGH WILL GRAD WEAKEN OVER THE
WEEKEND AND WILL SEE WINDS SLOWLY DIMINISH. THE NAM IS TRYING TO
DEVELOP A STRONGER LOW OFFSHORE ON SAT THAN THE 00Z GFS...BUT WITH
THE NAM POORER IN THESE SITUATIONS WILL FAVOR THE GFS FOR NOW.
DESPITE LOWERING WINDS LONG NE FETCH WILL KEEP SEAS AOA SCA LVLS
FROM LOOKOUT N. STARTING EARLY NEXT WEEK ANOTHER STRONG HIGH WILL
BE BUILDING TO THE N WITH MDLS SHOWING LOW PRES DEVELOPING TO THE
S BY MIDWEEK. THIS WILL AGAIN LEAD TO INCREASING N/NE WINDS MON
INTO TUE. AT THIS TIME LOOKS LIKE STRONGEST WINDS WILL BE MAINLY
BEYOND THIS FCST PD AS LOW PRES IS EXPECTED TO LIFT N TOWARD NC
WED/THU TIME FRAME. IF LOW DOES DEVELOP WILL HAVE POTENTIAL FOR AT
LEAST GALES MID PART OF NEXT WEEK WITH THREAT OF OVERWASH...BUT
HAVE PLENTY OF TIME TO WATCH THIS EVOLVE.
.RIP CURRENTS...STRONG WINDS AND BUILDING SEAS WILL LEAD TO HIGH
RIP THREAT FRI FOR ALL EAST FACING BEACHES FROM LOOKOUT N AND A
MODERATE THREAT FROM SURF CITY TO BOGUE INLET.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...HIGH SURF ADVISORY UNTIL 8 AM EDT SATURDAY FOR NCZ103.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT SATURDAY FOR AMZ130-135.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT TUESDAY FOR AMZ150-152-154-
156.
SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR AMZ158.
&&
$$
SYNOPSIS...BTC
NEAR TERM...MW
SHORT TERM...BTC
LONG TERM...BTC
AVIATION...JME/SJ
MARINE...JME/SJ
000
FXUS62 KILM 191333
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
934 AM EDT FRI SEP 19 2008
.SYNOPSIS...
HIGH PRESSURE ACROSS THE NORTHEAST WILL RIDGE INTO THE CAROLINAS
THROUGH THE WEEKEND AND BRING COOLER THAN NORMAL TEMPERATURES TO THE
REGION. A TROUGH OF LOW PRESSURE WILL DEVELOP OFFSHORE AND MOVE JUST
CLOSE ENOUGH TO THE AREA TO INCREASE THE CHANCE OF SHOWERS LATE IN
THE WEEKEND AND INTO EARLY NEXT WEEK...MAINLY ALONG THE COASTAL
COUNTIES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 9 AM FRIDAY...BREEZY NORTHEAST WINDS THIS AFTERNOON ARE THE
RESULT OF A PRESSURE GRADIENT BETWEEN A HIGH CENTERED OVER MAINE
AND A FRONTAL BOUNDARY WELL OFF THE COAST. ANOTHER RAIN FREE DAY
OVER LAND IS FORECAST AS MOISTURE CONTINUES TO BE LIMITED. MORNING
SOUNDINGS ALSO SHOW AN INVERSION AROUND 825 MB FROM THE HIGH PRESSURE
RIDGE. THIS IS CONFIRMED BY THE 12 UTC RUC WHICH SHOWS AROUND 90
PERCENT OF THE AREA BEING STABLE. THE ONLY AREA THAT SHOWS ANY
INSTABILITY THIS AFTERNOON BEING EASTERN BRUNSWICK AND NEW HANOVER
COUNTY. WITH THE CAP AT 825 MB DO NOT EXPECT ANY PRECIPITATION OVER
THIS AREA THIS AFTERNOON JUST SOME CONVECTIVE ROLES.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...STILL EXPECTING A COOL AND RELATIVELY DRY WEEKEND AS
HIGH PRESSURE ANCHORED TO THE NORTH AND AN OLD FRONT AND LOW
PRESSURE TO THE EAST WILL BE THE MAIN PLAYERS. THE GFS HAS TRENDED A
LITTLE DRIER WITH THE QPF...WHICH WASNT OVERLY IMPRESSIVE IN THE
FIRST PLACE AS THE SHIELD HAS JOGGED TO THE EAST. THE FLOW HAS
BACKED TO A MORE NORTHERLY DIRECTION AS WELL PROBABLY DUE TO A WEAK
CLOSED CIRCULATION DEVELOPING OVER THE GULF STREAM. ALL OF THIS
SAID...HAVE TRIMMED POPS BACK EVER SO SLIGHTLY TO REPRESENT THIS
TREND...MAINLY CONFINING THEM TO THE COASTAL COUNTIES WITH THE
EXCEPTION OF LATE SATURDAY INTO SUNDAY MORNING WHEN A FEW SPRINKLES
COULD MIGRATE INLAND.
SOME SIGNIFICANT DIFFERENCES REGARDING THE TEMPERATURE GUIDANCE FOR
THE PERIOD WITH THE MET NUMBERS A CATEGORY COOLER IN SOME INSTANCES.
A FEW WEEKS AGO DURING THE HEAT OF THE SUMMER THE SOLUTION WOULD BE
SIMPLE...GO WITH THE MET. WITH THE FALL QUICKLY APPROACHING AND THE
FACT THE MAV NUMBERS HAVE BEEN BETTER AT LEAST DURING THE INITIAL
STAGES OF THIS AIR MASS THE SOLUTION IS A BIT MORE COMPLEX. WILL
UNDERCUT THE MAV NUMBERS A DEGREE OR TWO AS THE MET NUMBERS JUST
SEEM TOO COOL.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...STILL A LOT OF UNCERTAINTY REGARDING THE POSSIBLE
DEVELOPMENT OF LOW PRESSURE OFF THE COAST WHICH WILL BE THE FOCUS
OF THE EXTENDED OR MORE SPECIFICALLY THE LATTER HALF OF THE
EXTENDED...FROM WEDNESDAY ON. THE LATEST OPERATIONAL GFS HAS
SHIFTED THE LOW PRESSURE TO THE SOUTH AND EAST. THE ENSEMBLE
MEMBERS SEEM TO HAVE SOMETHING FOR EVERYONE...WITH LOW PRESSURE
FROM THE BAHAMAS ALL THE WAY TO THE NORTH JUST EAST OF HATTERAS.
OBVIOUSLY THERE IS STILL NOTHING TO HANG OUR HATS ON AND I SUSPECT
IT WILL REMAIN SO FOR THE NEXT FEW DAYS. I TRIMMED BACK POPS AND
CLOUD COVER SLIGHTLY TO REPRESENT A TREND IF NOTHING ELSE BUT
CONFIDENCE IN LOWER THAN USUAL IN THE EXTENDED.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS THROUGH THE FORECAST PERIOD. TIGHT GRADIENT TODAY
WILL RESULT IN STRONG BOUNDARY LAYER WINDS ONCE AIRMASS BECOMES
WELL MIXED...A COUPLE OF HOURS AFTER DAYBREAK. FLAT CU DECK
DEVELOP IN THE AFTERNOON BUT CONDITIONS REMAIN VFR. WINDS WILL
DIMINISH SOMEWHAT TOWARD THE END OF THE PERIOD.
OUTLOOK THROUGH MONDAY...QUITE A BIT OF UNCERTAINTY SATURDAY THROUGH
TUESDAY. CONTINUED NORTHEAST FLOW...WITH LOW PRESSURE POSSIBLY
SETTING UP CLOSE ENOUGH TO SHORE TO AFFECT COASTAL TERMINALS WITH
LOWER CEILINGS AND RAIN SATURDAY/SUNDAY. IF THE LOW SETS UP FURTHER
OFFSHORE...LOOK FOR VFR CONDITIONS...HOWEVER WINDY CONDITIONS ARE
EXPECTED SATURDAY...MONDAY AND TUESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 9 AM FRIDAY...A TIGHT PRESSURE GRADIENT RESULTING FROM HIGH
PRESSURE OVER MAINE AND AN OLD FRONT OFF THE COAST IS PRODUCING
STRONG NORTHEAST WINDS. AT 9 AM FRYING PAN WAS REPORTING NORTHEAST
WINDS OF 25 KNOTS AND SEAS OF 8 FEET. CLOSE TO THE COAST SEAS AROUND
4 FEET WERE BEING OBSERVED. AS THE PRESSURE GRADIENT CONTINUE THROUGH
TONIGHT SEAS AND WINDS WILL REMAIN HIGH AND SMALL CRAFT CONDITIONS
WILL CONTINUE INTO SATURDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT SATURDAY FOR AMZ250-252-
254-256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...HAWKINS
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...III
000
FXUS62 KRAH 191130
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
730 AM EDT FRI SEP 19 2008
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL BUILD DOWN THE ATLANTIC SEABOARD THROUGH
THE WEEKEND...BRINGING COOL AND DRY CONDITIONS TO CENTRAL NORTH
CAROLINA.
&&
.NEAR TERM /TODAY/...
AS OF 215 AM FRIDAY...
HIGH PRESSURE BUILDING DOWN THE ATLANTIC COAST WILL COMBINE WITH AN
INVERTED TROUGH ALONG THE COAST... THE RESULT WILL BE INCREASING
NORTHEAST WINDS AT 10 TO 125 MPH WITH GUSTS TO 25 MPH DURING THE
AFTERNOON. CLOUDINESS ADVECTING SOUTH DUE TO THE NORTHEAST FLOW
WILL INCREASE ACROSS THE AREA TODAY... RESULTING IN PARTLY SUNNY
SKIES. THE CLOUDS WILL HOLD TEMPERATURES DOWN A FEW DEGREES OVER
HIGHS OF THURSDAY...THEY WILL BE IT HE MID TO UPPER 70S.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 230 AM FRIDAY...
HIGH PRESSURE CONTINUES TO BUILD DOWN THE COAST FRIDAY NIGHT THROUGH
SATURDAY... HOWEVER THE SYSTEM BECOME QUITE BAGGY SUNDAY AND SUNDAY
NIGHT AS A HIGH CENTER SETTLE OVER NORTHWEST NORTH CAROLINA. VARYING
AMOUNTS OF CLOUD COVER THROUGH THE PERIOD WITH THE HIGHEST
CONCENTRATION ALONG THE COAST IN CONJUNCTION WITH AN OFFSHORE LOW
PRESSURE CENTER. LOWS IN THE MID TO UPPER 50S FRIDAY NIGHT AND
SATURDAY NIGHT AND IN UPPER 50S TO LOWER 60S SOUTHEAST SUNDAY NIGHT.
SLIGHT WARMING TREND THROUGH THE PERIOD...WITH HIGHS IN THE MID TO
UPPER 70S SATURDAY AND UPPER 70S TO AROUND 80 SUNDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 AM FRIDAY...
ANOTHER COOL HIGH PRESSURE AREA WILL BUILD SOUTH ACROSS THE AREA
FROM EASTERN CANADA. IT WILL MAINTAIN ITS PRESENCE AND NORTHEAST
FLOW THROUGH THE PERIOD. THE MAIN CHANGE WILL BE A RETURN TO COOLER
TEMPERATURES AFTER MONDAY WITH HIGH GENERALLY IN THE MID TO UPPER
70S. LOWS WILL BE IN THE 50S. A DRY FORECAST WILL BE MAINTAINED...
HOWEVER VARYING AMOUNTS OF CLOUDS WILL PREVAIL THROUGH THE PERIOD AS
A LOW PRESSURE SYSTEM OFFSHORE ENHANCES NORTHEAST FLOW ESPECIALLY
OVER THE EAST.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 730 AM FRIDAY...
LOCAL AREA WIND PROFILES SHOW WINDS OF 20-30 KT IN THE LOWEST 2000
FT THIS MORNING. WHILE THIS PRODUCED LOW LEVEL WIND SHEAR EARLIER
THIS MORNING...MIXING WILL SOON COMMENCE RESULTING IN GUSTY SFC
WINDS INSTEAD OF LLWS. SUSTAINED WINDS ARE EXPECTED TO BE 10-15 KT
ACROSS THE ENTIRE REGION...WITH GUSTS OF 20 KT OR SLIGHTLY HIGHER AT
RDU/FAY/RWI. WHILE GUSTS WILL DIMINISH CLOSE TO SUNSET...SUSTAINED
WINDS WILL STAY CLOSE TO 10 KT IN THE EAST DUE TO THE PERSISTENT
STRONG SFC PRESSURE GRADIENT. ANOTHER EPISODE OF LLWS POSSIBLE EARLY
SATURDAY MORNING IF SFC WINDS DECREASE SUBSTANTIALLY.
A WEAK SFC-850 MB BOUNDARY LOCATED OVER SOUTHERN VIRGINIA WILL PUSH
FURTHER SOUTH TODAY. BROKEN STRATOCUMULUS HAS DEVELOPED BEHIND THIS
FEATURE OVER VIRGINIA AND THIS CLOUD DECK SHOULD MOVE INTO PORTIONS
OF CENTRAL NORTH CAROLINA THIS MORNING. THE BEST MOISTURE PROFILES
WILL BE LOCATED OVER THE TRIAD...SO EXPECTING PERIODS OF BROKEN VFR
CIGS... WITH CLOUD COVER MORE SCATTERED IN NATURE FURTHER EAST
TOWARD RWI. MODEL GUIDANCE IN GOOD AGREEMENT ON BRINGING IN ANOTHER
SURGE OF LOW LEVEL MOISTURE INTO THE REGION FROM THE EAST OVERNIGHT.
WILL INTRODUCE A LOW END MVFR CIGS AT RWI/FAY/RDU CLOSE TO DAYBREAK
SATURDAY.
GENERAL VFR CONDITIONS WILL PERSIST THROUGH MIDWEEK WITH HIGH
PRESSURE RIDGING IN FROM THE NORTH. HOWEVER...PERSISTENT
NORTHEASTERLY FLOW WILL LIKELY BRING IN PERIODS OF CLOUDINESS...
POTENTIALLY IN THE MVFR CATEGORY AT TIMES.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RHJ
NEAR TERM...RHJ
SHORT TERM...RHJ
LONG TERM...RHJ
AVIATION...JFB
000
FXUS62 KILM 191126
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
726 AM EDT FRI SEP 19 2008
.SYNOPSIS...
HIGH PRESSURE ACROSS THE NORTHEAST WILL RIDGE INTO THE CAROLINAS
THROUGH THE WEEKEND AND BRING COOLER THAN NORMAL TEMPERATURES TO THE
REGION. A TROUGH OF LOW PRESSURE WILL DEVELOP OFFSHORE AND MOVE JUST
CLOSE ENOUGH TO THE AREA TO INCREASE THE CHANCE OF SHOWERS LATE IN
THE WEEKEND AND INTO EARLY NEXT WEEK...MAINLY ALONG THE COASTAL
COUNTIES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM FRIDAY...ANOTHER BREEZY DAY TODAY AS SFC HIGH OVER NEW
ENGLAND CONTINUES TO BUILD DOWN THE E COAST TODAY. ELONGATED SFC LOW
TAKING SHAPE ALONG STALLED FRONT OFF THE E COAST WILL STRENGTHEN
SLIGHTLY AS IT SLOWLY RETROGRADES AND PINCHES THE SFC GRADIENT. MID
LEVEL DRY AIR AND CAPPING WILL AGAIN KEEP SKIES MOSTLY CLEAR WITH
ONLY A FEW AFTN CU DEVELOPING. VERTICAL EXTENT OF CU MAY BE A LITTLE
HIGHER THAN YESTERDAY...BUT STILL NOT ENOUGH TO PRODUCE ANY PRECIP.
HIGHS WILL BE NEAR TO SLIGHTLY BELOW CLIMO.
CLOUDS BEGIN TO INCREASE LATE TONIGHT AS SFC LOW/TROF OFF THE E
COAST IS SLOWLY PUSHED W BY SFC AND MID LEVEL RIDGING. LOW AND MID
LEVEL MOISTURE WILL BE INCREASING OVERNIGHT BUT LACK OF ANY FORCING
MECHANISM WILL PROBABLY KEEP MEASURABLE PRECIP OUT OF THE CWA
THROUGH THE PERIOD. SOME ISOLATED SHOWERS MAY DEVELOP ACROSS THE
WATERS AND MOVE INLAND CLOSER TO MORNING...BUT THESE WOULD BE SHORT
LIVED ONCE THEY MOVED ONSHORE. INCREASING CLOUD COVER AND BREEZY
CONDITIONS WILL HELP KEEP LOWS NEAR CLIMO FRI NIGHT.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...STILL EXPECTING A COOL AND RELATIVELY DRY WEEKEND AS
HIGH PRESSURE ANCHORED TO THE NORTH AND AN OLD FRONT AND LOW
PRESSURE TO THE EAST WILL BE THE MAIN PLAYERS. THE GFS HAS TRENDED A
LITTLE DRIER WITH THE QPF...WHICH WASNT OVERLY IMPRESSIVE IN THE
FIRST PLACE AS THE SHIELD HAS JOGGED TO THE EAST. THE FLOW HAS
BACKED TO A MORE NORTHERLY DIRECTION AS WELL PROBABLY DUE TO A WEAK
CLOSED CIRCULATION DEVELOPING OVER THE GULF STREAM. ALL OF THIS
SAID...HAVE TRIMMED POPS BACK EVER SO SLIGHTLY TO REPRESENT THIS
TREND...MAINLY CONFINING THEM TO THE COASTAL COUNTIES WITH THE
EXCEPTION OF LATE SATURDAY INTO SUNDAY MORNING WHEN A FEW SPRINKLES
COULD MIGRATE INLAND.
SOME SIGNIFICANT DIFFERENCES REGARDING THE TEMPERATURE GUIDANCE FOR
THE PERIOD WITH THE MET NUMBERS A CATEGORY COOLER IN SOME INSTANCES.
A FEW WEEKS AGO DURING THE HEAT OF THE SUMMER THE SOLUTION WOULD BE
SIMPLE...GO WITH THE MET. WITH THE FALL QUICKLY APPROACHING AND THE
FACT THE MAV NUMBERS HAVE BEEN BETTER AT LEAST DURING THE INITIAL
STAGES OF THIS AIR MASS THE SOLUTION IS A BIT MORE COMPLEX. WILL
UNDERCUT THE MAV NUMBERS A DEGREE OR TWO AS THE MET NUMBERS JUST
SEEM TOO COOL.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...STILL A LOT OF UNCERTAINTY REGARDING THE POSSIBLE
DEVELOPMENT OF LOW PRESSURE OFF THE COAST WHICH WILL BE THE FOCUS
OF THE EXTENDED OR MORE SPECIFICALLY THE LATTER HALF OF THE
EXTENDED...FROM WEDNESDAY ON. THE LATEST OPERATIONAL GFS HAS
SHIFTED THE LOW PRESSURE TO THE SOUTH AND EAST. THE ENSEMBLE
MEMBERS SEEM TO HAVE SOMETHING FOR EVERYONE...WITH LOW PRESSURE
FROM THE BAHAMAS ALL THE WAY TO THE NORTH JUST EAST OF HATTERAS.
OBVIOUSLY THERE IS STILL NOTHING TO HANG OUR HATS ON AND I SUSPECT
IT WILL REMAIN SO FOR THE NEXT FEW DAYS. I TRIMMED BACK POPS AND
CLOUD COVER SLIGHTLY TO REPRESENT A TREND IF NOTHING ELSE BUT
CONFIDENCE IN LOWER THAN USUAL IN THE EXTENDED.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS THROUGH THE FORECAST PERIOD. TIGHT GRADIENT TODAY
WILL RESULT IN STRONG BOUNDARY LAYER WINDS ONCE AIRMASS BECOMES
WELL MIXED...A COUPLE OF HOURS AFTER DAYBREAK. FLAT CU DECK
DEVELOP IN THE AFTERNOON BUT CONDITIONS REMAIN VFR. WINDS WILL
DIMINISH SOMEWHAT TOWARD THE END OF THE PERIOD.
OUTLOOK THROUGH MONDAY...QUITE A BIT OF UNCERTAINTY SATURDAY THROUGH
TUESDAY. CONTINUED NORTHEAST FLOW...WITH LOW PRESSURE POSSIBLY
SETTING UP CLOSE ENOUGH TO SHORE TO AFFECT COASTAL TERMINALS WITH
LOWER CEILINGS AND RAIN SATURDAY/SUNDAY. IF THE LOW SETS UP FURTHER
OFFSHORE...LOOK FOR VFR CONDITIONS...HOWEVER WINDY CONDITIONS ARE
EXPECTED SATURDAY...MONDAY AND TUESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM FRIDAY...STRONG NE FLOW WILL CONTINUE THROUGH THE PERIOD
WITH GRADIENT REMAINING PINCHED AS SFC HIGH BUILD IN FROM THE N AND
SFC LOW/TROF OFF THE COAST DRIFTS SLOWLY W. BOTH WINDS AND SEAS WILL
REMAIN ABOVE SCA THRESHOLDS THROUGH THE PERIOD...REQUIRING THE
CONTINUATION OF FLAGS FOR ALL ZONES INTO SAT. PROLONGED PERIOD OF
STRONG NE FLOW WILL RESULT IN DOMINANT WAVE PERIODS INCREASING TO 8
TO 10 SECONDS BY SAT AM.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT SATURDAY FOR AMZ250-252-
254-256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...III
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...III/DL
000
FXUS62 KMHX 190720
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
320 AM EDT FRI SEP 19 2008
.SYNOPSIS...
STRONG HIGH PRESSURE WILL BUILD INTO THE AREA FROM NEW ENGLAND
TODAY. A WAVE OF LOW PRESSURE WILL MOVE NORTHEAST ALONG A SLOW
MOVING FRONTAL SYSTEM OFF THE SOUTHEAST COAST ON SATURDAY AND
SUNDAY. STRONG HIGH PRESSURE WILL AGAIN BUILD INTO THE AREA FROM
THE NORTH EARLY TO MID NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SEASONABLY COOL TEMPS EXPECTED TODAY AS STRONG SFC HIGH PRES
CONTS TO BUILD EAST OF THE MTNS FROM NORTHERN NEW ENG. HIGHS
LARGELY IN THE M-U70S WITH A FEW 80 DEG READINGS PSBL IN THE
NORMALLY WARMER INLAND LOCATIONS. PRES GRADIENT BTWN THE HIGH TO
THE NORTH AND WAVE OF LOW PRES DEVELOPING ALONG STALLED FNTL BNDRY
WELL OFF SE COAST WILL BRING WINDY CONDS ALONG THE COAST WITH
BREEZY CONDS INLAND. LOW LVL MOISTURE TRAPPED UNDER SUBSIDENCE
INVERSION WILL LEAD TO SCT OCNL BKN SC CLOUDS TODAY. EXPECT MOST
PCPN TO REMAIN OFFSHORE HUGGING THE BETTER BAROCLINICITY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
MODELS IN GENERAL AGREEMENT ON LIFTING THE DEVELOPING OFFSHORE
SFC WAVE NNE ALONG THE STALLED BNDRY THIS WEEKEND. HOWEVER GFS
APPEARS TO BE THROWING DEEPER MOISTURE (AND SUBSEQUENT PCPN CHCS)
TOO FAR INLAND. WILL LEAN TO A DRYER MODEL CONCENSUS AND KEEP
PCPN CHCS PINNED CLOSER TO THE COAST. A STRAY SHOWER CUD SNEAK IN
FARTHER INLAND AT JUST ABOUT ANYTIME DURING THE WEEKEND BUT EXPECT
MOST ACTIVITY WILL REMAIN RIGHT ALONG THE COAST (AND OFFSHORE) AS
DRYER AIR LIKELY WINS OUT OVER INLAND AREAS. SEASONABLY COOL CONDS
WILL REMAIN ON SATURDAY (HIGHS M-U70S) WITH A STIFF ONSHORE BREEZE
AND SCT/BKN SC CLOUDS. A FEW DEGS MILDER ON SUNDAY (HIGHS U70S/NR
80) AS SFC LOW PULLS FARTHER OFFSHORE ALLOWING ADDITIONAL SUN AND
WEAKER ONSHORE FLOW.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
STRONG SFC HIGH PRES RIDGING IN FROM THE NORTH WILL REINFORCE
OVER THE AREA EARLY TO MID NEXT WEEK FOR MORE MOSUNNY/SEASONABLY
COOL CONDS.
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
SOME LOW LEVEL MOISTURE STREAMING INTO THE REGION WILL GENERATE
SOME 3-4K FT CEILINGS LATE MORNING THROUGH THE AFT. MEANWHILE...WINDS
WILL GUST INTO THE LOWER TO MID 20S AS THE PRESSURE GRADIENT
BETWEEN THE STRONG HIGH TO THE N AND THE LOW OFFSHORE TIGHTENS
OVER THE AREA. TONIGHT THE WINDS WILL COME DOWN AS AN INVERSION
SETS UP. WILL SEE SOME OF THAT LOW LVL MOISTURE GET TRAPPED...AND
CEILINGS WILL DROP TO AROUND 2K FT...WITH SOME AREAS AS LOW AS 1K
FT LATE.
THE NE FLOW WILL CONTINUE THROUGH THE REST OF THE FORECAST...WITH
IMPROVED CONDITIONS EXPECTED SUN AND MON.
&&
.MARINE...
NO SIGNIFICANT CHANGE TO FORECAST AS CONDITIONS STILL LOOK
CONDUCIVE FOR PROLONGED SMALL CRAFT AND POSSIBLE GALE CONDITIONS
THOUGH NEXT WEEKEND. THIS IS THE RESULT OF BACK TO BACK STRONG
HIGH PRES CENTERS BUILDING OVER THE NE. THE FIRST ONE OVER NEW
ENGLAND CURRENTLY COMBINED WITH AN AREA OF LOW PRES OFFSHORE IS
INCREASING WINDS TO SOLID SCA. THE PRES GRAD WILL TIGHTEN
SLIGHTLY...WITH WINDS 25 TO 30 KT WITH GUSTS TO 35 KT POSSIBLE.
OFFSHORE WATERS CARRYING GALE CONDITIONS...MAINLY FOR GULF STREAM
FOR TODAY. THE STRONG WINDS WILL LEAD TO BUILDING SEAS WITH 8 TO
11 FEET EXPECTED CNTRL AND NRN WTRS FRI WITH 5 TO 8 FT S. THE
COMBO OF STRONG ONSHORE WINDS...HIGH ASTRO TIDES AND BUILDING SEAS
WILL LEAD TO HIGH SURF ADVRY CONDITIONS FROM HATTERAS NORTH
STARTING 12Z THROUGH SAT MORN. HIGH WILL GRAD WEAKEN OVER THE
WEEKEND AND WILL SEE WINDS SLOWLY DIMINISH. THE NAM IS TRYING TO
DEVELOP A STRONGER LOW OFFSHORE ON SAT THAN THE 00Z GFS...BUT WITH
THE NAM POORER IN THESE SITUATIONS WILL FAVOR THE GFS FOR NOW.
DESPITE LOWERING WINDS LONG NE FETCH WILL KEEP SEAS AOA SCA LVLS
FROM LOOKOUT N. STARTING EARLY NEXT WEEK ANOTHER STRONG HIGH WILL
BE BUILDING TO THE N WITH MDLS SHOWING LOW PRES DEVELOPING TO THE
S BY MIDWEEK. THIS WILL AGAIN LEAD TO INCREASING N/NE WINDS MON
INTO TUE. AT THIS TIME LOOKS LIKE STRONGEST WINDS WILL BE MAINLY
BEYOND THIS FCST PD AS LOW PRES IS EXPECTED TO LIFT N TOWARD NC
WED/THU TIME FRAME. IF LOW DOES DEVELOP WILL HAVE POTENTIAL FOR AT
LEAST GALES MID PART OF NEXT WEEK WITH THREAT OF OVERWASH...BUT
HAVE PLENTY OF TIME TO WATCH THIS EVOLVE.
.RIP CURRENTS...STRONG WINDS AND BUILDING SEAS WILL LEAD TO HIGH
RIP THREAT FRI FOR ALL EAST FACING BEACHES FROM LOOKOUT N.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...HIGH SURF ADVISORY FROM 8 AM THIS MORNING TO 8 AM EDT SATURDAY
FOR NCZ103.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT SATURDAY FOR AMZ130-135.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT TUESDAY FOR AMZ150-152-154-
156.
SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR AMZ158.
&&
$$
SYNOPSIS...BTC
NEAR TERM...BTC
SHORT TERM...BTC
LONG TERM...BTC
AVIATION...SJ
MARINE...SJ
000
FXUS62 KRAH 190705
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
300 AM EDT FRI SEP 19 2008
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL BUILD DOWN THE ATLANTIC SEABOARD THROUGH
THE WEEKEND...BRINGING COOL AND DRY CONDITIONS TO CENTRAL NORTH
CAROLINA.
&&
.NEAR TERM /TODAY/...
AS OF 215 AM FRIDAY...
HIGH PRESSURE BUILDING DOWN THE ATLANTIC COAST WILL COMBINE WITH AN
INVERTED TROUGH ALONG THE COAST... THE RESULT WILL BE INCREASING
NORTHEAST WINDS AT 10 TO 125 MPH WITH GUSTS TO 25 MPH DURING THE
AFTERNOON. CLOUDINESS ADVECTING SOUTH DUE TO THE NORTHEAST FLOW
WILL INCREASE ACROSS THE AREA TODAY... RESULTING IN PARTLY SUNNY
SKIES. THE CLOUDS WILL HOLD TEMPERATURES DOWN A FEW DEGREES OVER
HIGHS OF THURSDAY...THEY WILL BE IT HE MID TO UPPER 70S.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 230 AM FRIDAY...
HIGH PRESSURE CONTINUES TO BUILD DOWN THE COAST FRIDAY NIGHT THROUGH
SATURDAY... HOWEVER THE SYSTEM BECOME QUITE BAGGY SUNDAY AND SUNDAY
NIGHT AS A HIGH CENTER SETTLE OVER NORTHWEST NORTH CAROLINA. VARYING
AMOUNTS OF CLOUD COVER THROUGH THE PERIOD WITH THE HIGHEST
CONCENTRATION ALONG THE COAST IN CONJUNCTION WITH AN OFFSHORE LOW
PRESSURE CENTER. LOWS IN THE MID TO UPPER 50S FRIDAY NIGHT AND
SATURDAY NIGHT AND IN UPPER 50S TO LOWER 60S SOUTHEAST SUNDAY NIGHT.
SLIGHT WARMING TREND THROUGH THE PERIOD...WITH HIGHS IN THE MID TO
UPPER 70S SATURDAY AND UPPER 70S TO AROUND 80 SUNDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 AM FRIDAY...
ANOTHER COOL HIGH PRESSURE AREA WILL BUILD SOUTH ACROSS THE AREA
FROM EASTERN CANADA. IT WILL MAINTAIN ITS PRESENCE AND NORTHEAST
FLOW THROUGH THE PERIOD. THE MAIN CHANGE WILL BE A RETURN TO COOLER
TEMPERATURES AFTER MONDAY WITH HIGH GENERALLY IN THE MID TO UPPER
70S. LOWS WILL BE IN THE 50S. A DRY FORECAST WILL BE MAINTAINED...
HOWEVER VARYING AMOUNTS OF CLOUDS WILL PREVAIL THROUGH THE PERIOD AS
A LOW PRESSURE SYSTEM OFFSHORE ENHANCES NORTHEAST FLOW ESPECIALLY
OVER THE EAST.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 2 AM FRIDAY...
LOW LEVEL RIDGING BUILDING IN FROM THE NORTHEAST COMBINED WITH A
WEAK LOW AND SFC TROUGH OVER THE WESTERN ATLANTIC HAS TIGHTENED THE
LOW LEVEL GRADIENT ACROSS EASTERN NORTH CAROLINA. LOCAL RADAR WIND
PROFILES AND THE RALEIGH AIR QUALITY PROFILE CONFIRM THAT WINDS HAVE
INCREASE TO 25-35KT IN THE 1-2 KFT LAYER FROM RDU SOUTH AND EAST.
MEANWHILE...THE NOCTURNAL INVERSION HAS KEPT WINDS JUST AROUND 5 KT
AT THE SFC. THIS IS CURRENTLY RESULTING IN LOW LEVEL WIND SHEAR AT
RDU/FAY/RWI AND SHOULD PERSIST THROUGH DAYBREAK. THE GRADIENT FLOW
IS 5-10 KT WEAKER AT GSO/INT...THUS LLWS HAS NOT BEEN INCLUDED IN
THE TAFS THERE. THE OTHER CONCERN FOR THE DAYBREAK HOURS IS THE
ADVECTION OF LOW LEVEL MOISTURE UNDER THE NORTHEAST WIND FLOW. VFR
CIGS (GENERALLY 5-7 KFT) HAVE DEVELOPED IN CENTRAL VIRGINIA.
MEANWHILE...ADDITIONAL LOWER STRATUS WITH BASES AROUND 2 KFT HAS
DEVELOPED JUST OFFSHORE THE SE VA/NE NC COASTS. THIS MOISTURE SHOULD
CONTINUE TO ADVECT SOUTHWESTWARD AND MAY RESULT IN LOW END MVFR CIGS
AT RDU/RWI/FAY BETWEEN 10-13Z.
SCATTERED TO BROKEN VFR STRATOCUMULUS IS EXPECTED TO LINGER THROUGH
MUCH OF THE DAY UNDER THE PERSISTENT MOIST NORTHEAST FLOW. CLOUDS
SHOULD DIMINISH IN THE EVENING AS THE HIGHEST LOW LEVEL MOISTURE
MOVES FURTHER SOUTH AND WEST. WINDS ARE APT TO BE BREEZY
TODAY...PARTICULARLY AT THE EASTERN TERMINALS WHERE THE GRADIENT IS
TIGHTER. SUSTAINED WINDS EXPECTED TO BE 10-15 KT ACROSS THE ENTIRE
REGION...WITH GUSTS OF 20 KT OR SLIGHTLY HIGHER AT RDU/FAY/RWI.
WHILE GUSTS WILL DIMINISH CLOSE TO SUNSET...SUSTAINED WINDS WILL
STAY CLOSE TO 10 KT IN THE EAST DUE TO THE PERSISTENT STRONG SFC
PRESSURE GRADIENT. ANOTHER EPISODE OF LLWS POSSIBLE EARLY SATURDAY
MORNING IF SFC WINDS DECREASE SUBSTANTIALLY.
ANOTHER PERIOD OF CLOUDINESS MAY OCCUR SATURDAY AND SATURDAY NIGHT
AS MOISTURE POOLS ALONG A TROUGH POSITIONED ALONG THE COAST. A
SECOND PERIOD OF LOW STRATUS IS EXPECTED MONDAY NIGHT. OTHERWISE VFR
CONDITIONS EXPECTED.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RHJ
NEAR TERM...RHJ
SHORT TERM...RHJ
LONG TERM...RHJ
AVIATION...JFB
000
FXUS62 KILM 190653
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
253 AM EDT FRI SEP 19 2008
.SYNOPSIS...
HIGH PRESSURE ACROSS THE NORTHEAST WILL RIDGE INTO THE CAROLINAS
THROUGH THE WEEKEND AND BRING COOLER THAN NORMAL TEMPERATURES TO THE
REGION. A TROUGH OF LOW PRESSURE WILL DEVELOP OFFSHORE AND MOVE JUST
CLOSE ENOUGH TO THE AREA TO INCREASE THE CHANCE OF SHOWERS LATE IN
THE WEEKEND AND INTO EARLY NEXT WEEK...MAINLY ALONG THE COASTAL
COUNTIES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM FRIDAY...ANOTHER BREEZY DAY TODAY AS SFC HIGH OVER NEW
ENGLAND CONTINUES TO BUILD DOWN THE E COAST TODAY. ELONGATED SFC LOW
TAKING SHAPE ALONG STALLED FRONT OFF THE E COAST WILL STRENGTHEN
SLIGHTLY AS IT SLOWLY RETROGRADES AND PINCHES THE SFC GRADIENT. MID
LEVEL DRY AIR AND CAPPING WILL AGAIN KEEP SKIES MOSTLY CLEAR WITH
ONLY A FEW AFTN CU DEVELOPING. VERTICAL EXTENT OF CU MAY BE A LITTLE
HIGHER THAN YESTERDAY...BUT STILL NOT ENOUGH TO PRODUCE ANY PRECIP.
HIGHS WILL BE NEAR TO SLIGHTLY BELOW CLIMO.
CLOUDS BEGIN TO INCREASE LATE TONIGHT AS SFC LOW/TROF OFF THE E
COAST IS SLOWLY PUSHED W BY SFC AND MID LEVEL RIDGING. LOW AND MID
LEVEL MOISTURE WILL BE INCREASING OVERNIGHT BUT LACK OF ANY FORCING
MECHANISM WILL PROBABLY KEEP MEASURABLE PRECIP OUT OF THE CWA
THROUGH THE PERIOD. SOME ISOLATED SHOWERS MAY DEVELOP ACROSS THE
WATERS AND MOVE INLAND CLOSER TO MORNING...BUT THESE WOULD BE SHORT
LIVED ONCE THEY MOVED ONSHORE. INCREASING CLOUD COVER AND BREEZY
CONDITIONS WILL HELP KEEP LOWS NEAR CLIMO FRI NIGHT.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...STILL EXPECTING A COOL AND RELATIVELY DRY WEEKEND AS
HIGH PRESSURE ANCHORED TO THE NORTH AND AN OLD FRONT AND LOW
PRESSURE TO THE EAST WILL BE THE MAIN PLAYERS. THE GFS HAS TRENDED A
LITTLE DRIER WITH THE QPF...WHICH WASNT OVERLY IMPRESSIVE IN THE
FIRST PLACE AS THE SHIELD HAS JOGGED TO THE EAST. THE FLOW HAS
BACKED TO A MORE NORTHERLY DIRECTION AS WELL PROBABLY DUE TO A WEAK
CLOSED CIRCULATION DEVELOPING OVER THE GULF STREAM. ALL OF THIS
SAID...HAVE TRIMMED POPS BACK EVER SO SLIGHTLY TO REPRESENT THIS
TREND...MAINLY CONFINING THEM TO THE COASTAL COUNTIES WITH THE
EXCEPTION OF LATE SATURDAY INTO SUNDAY MORNING WHEN A FEW SPRINKLES
COULD MIGRATE INLAND.
SOME SIGNIFICANT DIFFERENCES REGARDING THE TEMPERATURE GUIDANCE FOR
THE PERIOD WITH THE MET NUMBERS A CATEGORY COOLER IN SOME INSTANCES.
A FEW WEEKS AGO DURING THE HEAT OF THE SUMMER THE SOLUTION WOULD BE
SIMPLE...GO WITH THE MET. WITH THE FALL QUICKLY APPROACHING AND THE
FACT THE MAV NUMBERS HAVE BEEN BETTER AT LEAST DURING THE INITIAL
STAGES OF THIS AIR MASS THE SOLUTION IS A BIT MORE COMPLEX. WILL
UNDERCUT THE MAV NUMBERS A DEGREE OR TWO AS THE MET NUMBERS JUST
SEEM TOO COOL.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...STILL A LOT OF UNCERTAINTY REGARDING THE POSSIBLE
DEVELOPMENT OF LOW PRESSURE OFF THE COAST WHICH WILL BE THE FOCUS
OF THE EXTENDED OR MORE SPECIFICALLY THE LATTER HALF OF THE
EXTENDED...FROM WEDNESDAY ON. THE LATEST OPERATIONAL GFS HAS
SHIFTED THE LOW PRESSURE TO THE SOUTH AND EAST. THE ENSEMBLE
MEMBERS SEEM TO HAVE SOMETHING FOR EVERYONE...WITH LOW PRESSURE
FROM THE BAHAMAS ALL THE WAY TO THE NORTH JUST EAST OF HATTERAS.
OBVIOUSLY THERE IS STILL NOTHING TO HANG OUR HATS ON AND I SUSPECT
IT WILL REMAIN SO FOR THE NEXT FEW DAYS. I TRIMMED BACK POPS AND
CLOUD COVER SLIGHTLY TO REPRESENT A TREND IF NOTHING ELSE BUT
CONFIDENCE IN LOWER THAN USUAL IN THE EXTENDED.
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS THROUGH THE FORECAST PERIOD. TIGHT GRADIENT SETS UP
FOR FRIDAY. KEPT THE WINDS UP AS BUFKIT SHOWS STRONG WINDS AT THE
BOUNDARY LAYER...WITH THINGS MIXING PRETTY GOOD A COUPLE OF HOURS
AFTER DAYBREAK. WILL BITE ON THE STRATA CU DECK BEGINNING FRIDAY
AFTERNOON. SHOULD REMAIN VFR. WINDS WILL DIMINISH SOMEWHAT TOWARD
THE END OF THE 24 HOUR FORECAST PERIOD.
OUTLOOK THROUGH MONDAY...QUITE A BIT OF UNCERTAINTY SATURDAY THROUGH
TUESDAY. CONTINUED NORTHEAST FLOW...WITH LOW PRESSURE POSSIBLY
SETTING UP CLOSE ENOUGH TO SHORE TO AFFECT COASTAL TERMINALS WITH
LOWER CEILINGS AND RAIN SATURDAY/SUNDAY. IF THE LOW SETS UP FURTHER
OFFSHORE...LOOK FOR VFR CONDITIONS...HOWEVER WINDY CONDITIONS ARE
EXPECTED SATURDAY...MONDAY AND TUESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM FRIDAY...STRONG NE FLOW WILL CONTINUE THROUGH THE PERIOD
WITH GRADIENT REMAINING PINCHED AS SFC HIGH BUILD IN FROM THE N AND
SFC LOW/TROF OFF THE COAST DRIFTS SLOWLY W. BOTH WINDS AND SEAS WILL
REMAIN ABOVE SCA THRESHOLDS THROUGH THE PERIOD...REQUIRING THE
CONTINUATION OF FLAGS FOR ALL ZONES INTO SAT. PROLONGED PERIOD OF
STRONG NE FLOW WILL RESULT IN DOMINANT WAVE PERIODS INCREASING TO 8
TO 10 SECONDS BY SAT AM.
&&
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...A NORTH TO NORTHEAST FLOW WILL PREVAIL THROUGH THE
PERIOD. THE DILEMMA IS WHAT WILL BE THE MAGNITUDE OF THE FLOW AS
THE NAM/WRF IS MUCH STRONGER WITH THE GRADIENT DUE TO THE CLOSED
LOW OVER THE GULF STREAM BEING DEEPER. THERE IS A GOOD 10 TO 12
KNOTS DIFFERENCE IN THE MARINE GUIDANCE FOR 41013 WHEN COMPARING
THE NAM AND MAV BULLETINS. I LIKE THE GFS BUT CANT DISREGARD THE
NAM COMPLETELY AND WILL INCREASE THE GFS WINDS ANS SEAS A BIT
ACROSS THE BOARD. WITH THIS IN MIND...EXPECT SMALL CRAFT
CONDITIONS TO CONTINUE SATURDAY AND WILL EXTEND THROUGH THE DAY
WITH SUFFICIENT CONFIDENCE.
COULD BE A SIMILAR SITUATION SUNDAY AS THE NAM CONTINUES WITH THE
ROBUST SOLUTION. FOR NOW HAVE WINDS AND SEAS DROPPING BELOW FLAG
CRITERIA BUT SUBSEQUENT SHIFTS WILL HAVE TO MONITOR TRENDS CLOSELY.
&&
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 AM FRIDAY...NORTHEAST FLOW THROUGH THE PERIOD...MOST LIKELY BELOW
FLAG CRITERIA. NO CHANGES TO THE EXTENDED COASTAL WATERS FORECAST
THIS MORNING.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 6 PM EDT
SATURDAY FOR AMZ250-252-254-256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...III
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...III/DL
000
FXUS62 KRAH 190650
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
245 AM EDT FRI SEP 19 2008
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL BUILD DOWN THE ATLANTIC SEABOARD THROUGH
THE WEEKEND...BRINGING COOL AND DRY CONDITIONS TO CENTRAL NORTH
CAROLINA.
&&
.NEAR TERM /TODAY/...
AS OF 215 AM FRIDAY...
HIGH PRESSURE BUILDING DOWN THE ATLANTIC COAST WILL COMBINE WITH AN
INVERTED TROUGH ALONG THE COAST... THE RESULT WILL BE INCREASING
NORTHEAST WINDS AT 10 TO 125 MPH WITH GUSTS TO 25 MPH DURING THE
AFTERNOON. CLOUDINESS ADVECTING SOUTH DUE TO THE NORTHEAST FLOW
WILL INCREASE ACROSS THE AREA TODAY... RESULTING IN PARTLY SUNNY
SKIES. THE CLOUDS WILL HOLD TEMPERATURES DOWN A FEW DEGREES OVER
HIGHS OF THURSDAY...THEY WILL BE IT HE MID TO UPPER 70S.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 230 AM FRIDAY...
HIGH PRESSURE CONTINUES TO BUILD DOWN THE COAST FRIDAY NIGHT THROUGH
SATURDAY... HOWEVER THE SYSTEM BECOME QUITE BAGGY SUNDAY AND SUNDAY
NIGHT AS A HIGH CENTER SETTLE OVER NORTHWEST NORTH CAROLINA. VARYING
AMOUNTS OF CLOUD COVER THROUGH THE PERIOD WITH THE HIGHEST
CONCENTRATION ALONG THE COAST IN CONJUNCTION WITH AN OFFSHORE LOW
PRESSURE CENTER. LOWS IN THE MID TO UPPER 50S FRIDAY NIGHT AND
SATURDAY NIGHT AND IN UPPER 50S TO LOWER 60S SOUTHEAST SUNDAY NIGHT.
SLIGHT WARMING TREND THROUGH THE PERIOD...WITH HIGHS IN THE MID TO
UPPER 70S SATURDAY AND UPPER 70S TO AROUND 80 SUNDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 245 PM THURSDAY...
MONDAY THROUGH WEDNESDAY...UPPER LEVEL RIDGE WILL BUILD FROM TX
INTO THE GREAT LAKES/SOUTHERN ONTARIO THROUGH THIS PERIOD WITH
BAGGY UPPER LEVEL TROUGH OFF THE NEW ENGLAND COAST EXTENDING SOUTH
SOUTHWEST TO THE VICINITY OF THE SOUTHEAST UNITED STATES THE
BUILDING UPPER LEVEL RIDGE TO OUR WEST SHOULD STRENGTHEN A NORTH-
SOUTH SURFACE RIDGE FROM QUEBEC SOUTHWARD ALONG THE EASTERN
SEABOARD. THIS WEATHER PATTERN USUALLY SIGNALS A DRY AND SLIGHTLY
COOLER THAN NORMAL CONDITIONS FOR CENTRAL NORTH CAROLINA.
FOR WEDNESDAY THROUGH THURSDAY...MEDIUM RANGE GUIDANCE IN
REASONABLY GOOD AGREEMENT DEPICTING THE UPPER LEVEL RIDGE CLOSING
OFF AND DRIFTING SLOWLY EAST ACROSS NEW ENGLAND. THIS IS TURN
DEVELOPS A WEAK CLOSED UPPER LEVEL LOW OVER THE SOUTHEAST UNITED
STATES WHICH INDUCES SURFACE CYCLOGENESIS OFF THE GA/SC COAST.
WHILE NOT OUT OF THE REALM OF POSSIBILITIES...THIS TYPE OF PATTERN
IS A BIT ANOMALOUS TO THIS TIME OF YEAR AND THE UPPER LEVEL LOW IS
RATHER WEAK. WHILE BAROCLINICITY MAY INCREASE OFFSHORE WITH THE
COOLER AIR ASSOCIATED WITH THE BUILDING RIDGE CROSSING THE WARM
WATERS LEADING TO SOME CYCLOGENESIS...MODELS MAY BE UNDERPLAYING
THE DRY AIR AND SUBSIDENCE ASSOCIATED WITH THE SURFACE RIDGE OVER
CENTRAL NORTH CAROLINA. THUS...PREFER TO KEEP WEDNESDAY INTO
THURSDAY DRY WITH TEMPERATURES REMAINING SLIGHTLY BELOW NORMAL.
THE CONTRAST BETWEEN THE SURFACE RIDGE AND THE CONDITIONS OFFSHORE
MAY LEAD TO ENHANCE LOW LEVEL NORTHEAST FLOW OVER THE EASTERN
COUNTIES. FOR NOW...WILL MAINTAIN NEAR SURFACE WINDS THU AROUND
15 KNOTS.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 2 AM FRIDAY...
LOW LEVEL RIDGING BUILDING IN FROM THE NORTHEAST COMBINED WITH A
WEAK LOW AND SFC TROUGH OVER THE WESTERN ATLANTIC HAS TIGHTENED THE
LOW LEVEL GRADIENT ACROSS EASTERN NORTH CAROLINA. LOCAL RADAR WIND
PROFILES AND THE RALEIGH AIR QUALITY PROFILE CONFIRM THAT WINDS HAVE
INCREASE TO 25-35KT IN THE 1-2 KFT LAYER FROM RDU SOUTH AND EAST.
MEANWHILE...THE NOCTURNAL INVERSION HAS KEPT WINDS JUST AROUND 5 KT
AT THE SFC. THIS IS CURRENTLY RESULTING IN LOW LEVEL WIND SHEAR AT
RDU/FAY/RWI AND SHOULD PERSIST THROUGH DAYBREAK. THE GRADIENT FLOW
IS 5-10 KT WEAKER AT GSO/INT...THUS LLWS HAS NOT BEEN INCLUDED IN
THE TAFS THERE. THE OTHER CONCERN FOR THE DAYBREAK HOURS IS THE
ADVECTION OF LOW LEVEL MOISTURE UNDER THE NORTHEAST WIND FLOW. VFR
CIGS (GENERALLY 5-7 KFT) HAVE DEVELOPED IN CENTRAL VIRGINIA.
MEANWHILE...ADDITIONAL LOWER STRATUS WITH BASES AROUND 2 KFT HAS
DEVELOPED JUST OFFSHORE THE SE VA/NE NC COASTS. THIS MOISTURE SHOULD
CONTINUE TO ADVECT SOUTHWESTWARD AND MAY RESULT IN LOW END MVFR CIGS
AT RDU/RWI/FAY BETWEEN 10-13Z.
SCATTERED TO BROKEN VFR STRATOCUMULUS IS EXPECTED TO LINGER THROUGH
MUCH OF THE DAY UNDER THE PERSISTENT MOIST NORTHEAST FLOW. CLOUDS
SHOULD DIMINISH IN THE EVENING AS THE HIGHEST LOW LEVEL MOISTURE
MOVES FURTHER SOUTH AND WEST. WINDS ARE APT TO BE BREEZY
TODAY...PARTICULARLY AT THE EASTERN TERMINALS WHERE THE GRADIENT IS
TIGHTER. SUSTAINED WINDS EXPECTED TO BE 10-15 KT ACROSS THE ENTIRE
REGION...WITH GUSTS OF 20 KT OR SLIGHTLY HIGHER AT RDU/FAY/RWI.
WHILE GUSTS WILL DIMINISH CLOSE TO SUNSET...SUSTAINED WINDS WILL
STAY CLOSE TO 10 KT IN THE EAST DUE TO THE PERSISTENT STRONG SFC
PRESSURE GRADIENT. ANOTHER EPISODE OF LLWS POSSIBLE EARLY SATURDAY
MORNING IF SFC WINDS DECREASE SUBSTANTIALLY.
ANOTHER PERIOD OF CLOUDINESS MAY OCCUR SATURDAY AND SATURDAY NIGHT
AS MOISTURE POOLS ALONG A TROUGH POSITIONED ALONG THE COAST. A
SECOND PERIOD OF LOW STRATUS IS EXPECTED MONDAY NIGHT. OTHERWISE VFR
CONDITIONS EXPECTED.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RHJ
NEAR TERM...RHJ
SHORT TERM...RHJ
LONG TERM...
AVIATION...JFB
000
FXUS62 KRAH 190603
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
203 AM EDT FRI SEP 19 2008
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL EXTEND DOWN THE EAST COAST THROUGH THE
WEEKEND...BRINGING COOL AND DRY CONDITIONS TO CENTRAL NORTH CAROLINA.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 1030 PM THURSDAY...
DRY AND COMFORTABLY COOL CONDITIONS EXPECTED OVERNIGHT. A 1031 MB
SURFACE HIGH CENTERED OVER SOUTHERN QUEBEC THIS EVENING WILL
CONTINUE TO BUILD SOUTHWARD INTO OUR REGION TONIGHT. THE CURRENT
CLEAR SKIES SHOULD REMAIN SO MOST OF THE NIGHT... AND ALLOW
TEMPERATURES TO DIP TO BETWEEN 54 AND 59 DEGREES FOR OVERNIGHT LOW
TEMPERATURES. HOWEVER... SOME CLOUD COVER MAY INCREASE FROM THE
NORTH JUST PRIOR TO SUNRISE... AS MOISTURE CURRENTLY CENTERED AROUND
5 THSD FT INVOF A WEAK SURFACE TO H85 BACKDOOR FRONT OVER THE
DELMARVA THIS EVENING SPREADS SOUTHWESTWARD. THIS MAY RESULT IN A
PERIOD OF SCATTERED TO BROKEN STRATOCUMULUS/STRATUS SPREADING INTO
OUR AREA ON NORTHEAST FLOW BY DAYBREAK. IN FACT... THE MODELS
SUGGEST A SECOND SATURATED (STRATUS) LAYER MAY DEVELOP BETWEEN 1 AND
2 THSD FEET... AS THE LOW LEVELS COOL AND THE BAND OF MOISTURE
ARRIVES. THIS POSSIBILITY IS SUPPORTED BY THE UPSTREAM WALLOPS
ISLAND RAOB THAT REVEALS A SECONDARY INVERSION AND RELATIVELY MOIST
LAYER ALREADY AROUND 1200 FT.
A NOCTURNAL LOW LEVEL JET HAS ALSO DEVELOPED ABOVE THE DECOUPLED
SURFACE LAYER OVER THE COASTAL PLAIN OF NC PER RALNC AIR QUALITY
PROFILER AND KMHX VWP WIND DATA. IN FACT... THEY INDICATE WINDS
AROUND 2 THSD FT HAVE INCREASED TO BETWEEN 25 AND 35 KNOTS OVER THE
EASTERN THIRD OF THE STATE.... HIGHEST ALONG THE COAST. THIS LLJ IS
EXPECTED TO PERSIST IN THESE AREAS OVERNIGHT... AND MAY RESULTANTLY
AFFECT AVIATION INTERESTS - SEE AVIATION AFD BELOW. -MWS
AS OF 215 PM THURSDAY...
FOR FRIDAY... THE PRESSURE GRADIENT WILL CONTINUE TO TIGHTEN AS THE
SURFACE HIGH MOVES EAST WITH THE BAROCLINIC ZONE STILL SITTING OFF
THE COAST. AS THE LOW LEVEL INVERSION MIXES OUT IN THE MORNING... WE
SHOULD SEE PREVAILING NORTHEAST WINDS QUICKLY JUMP UP TO 10-20 MPH
WITH SOME GUSTS TO 25 MPH. OTHERWISE... THE AFOREMENTIONED BATCH OF
CLOUDS SHOULD CONTINUE MOVING SOUTHWEST TO THE SOUTHERN CWA FRIDAY
MORNING... LEAVING MOSTLY SUNNY SKIES... ALTHOUGH A FEW FLAT
CONVECTIVE CUMULUS MAY POP UP THROUGH THE AFTERNOON. WITH
THICKNESSES EXPECTED TO BE ONLY MARGINALLY LOWER THAN TODAY...
TEMPERATURES SHOULD FOLLOW SUIT... WITH HIGHS IN THE IN THE 76-81
RANGE. -GIH
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 245 PM THURSDAY...
FRIDAY NIGHT THROUGH SATURDAY...DRY AIR SURFACE RIDGE WILL STRETCH
FROM THE SOUTHERN NEW ENGLAND COAST TO THE WESTERN CAROLINAS.
MEANWHILE AN AREA OF LOW PRESSURE WILL MEANDER OFF CAPE FEAR. THE
DIFFERENCE IN PRESSURE BETWEEN THE RIDGE AND THE LOW OFFSHORE WILL
CREATE A STEADY NE FLOW OVER THE AREA WITH THE STEADY/BREEZY WINDS
EXPECTED EAST OF HIGHWAY 1. THIS CIRCULATION PATTERN WILL ADVECT
POCKETS OF MOISTURE IN THE LOWEST 10000FT FEET. THIS WILL RESULT IN
PERIODS OF CLOUDINESS...AGAIN MAINLY EAST OF HIGHWAY 1. MECHANISMS
FOR LIFT TO GENERATE PRECIPITATION ARE ABSENT SO DO NOT EXPECT ANY
PRECIPITATION THROUGH THE PERIOD.
THE LOW LEVEL NE FLOW WILL RESULT IN MAX TEMPS SLIGHTLY
COOLER THAN NORMAL. THICKNESSES WITH FULL TO PARTIAL SUN SUPPORT MAX
TEMPS MAINLY IN THE MID 70S. A STEADY NE WIND FRIDAY NIGHT WILL KEEP
THE BOUNDARY LAYER WELL MIXED. THIS SHOULD RESULT IN TEMPS A COUPLE
OF DEGREES WARMER THAN NORMALLY OCCUR WHEN THE WINDS DECOUPLE AT THE
SURFACE. USED A BLAND OF MOS TEMP GUIDANCE FOR MIN TEMP FORECAST FRI
NIGHT/SATURDAY MORNING.
SATURDAY NIGHT THROUGH SUNDAY NIGHT...NOT MUCH CHANGE IN THE
SENSIBLE WEATHER THROUGH THIS PERIOD. SURFACE RIDGE AXIS WILL
CONTINUE OVER THE WESTERN CAROLINAS WHILE SURFACE LOW OFFSHORE OF
CAPE FEAR IS FORECAST TO WEAKEN/DISSIPATE. RELAXING OF PRESSURE
GRADIENT WILL LEAD TO A WEAKER WIND FIELD. THE WEAKER NORTHEAST
FETCH WILL RESULT IN LESS CLOUDINESS BELOW 10000 FEET. HOWEVER...MAY
SEE SOME ENHANCEMENT OF HIGH LEVEL CLOUDINESS AS FLOW ALOFT BACKS AND
STRENGTHENS IN RESPONSE TO A MINOR SHORT WAVE THAT SHEARS NORTHEAST
ACROSS THE OHIO VALLEY. THUS EXPECT A CONTINUATION OF PARTLY CLOUDY
SKIES.
THICKNESSES SUNDAY REBOUND 10 TO 13 METERS FROM SATURDAY THICKNESSES.
THE MODERATING AIR MASS COUPLED WITH A WEAKER NE SURFACE FLOW
SHOULD TRANSLATES TO MAX TEMPERATURES 3 TO 5 DEGREES WARMER SUNDAY
COMPARED TO SATURDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 245 PM THURSDAY...
MONDAY THROUGH WEDNESDAY...UPPER LEVEL RIDGE WILL BUILD FROM TX
INTO THE GREAT LAKES/SOUTHERN ONTARIO THROUGH THIS PERIOD WITH
BAGGY UPPER LEVEL TROUGH OFF THE NEW ENGLAND COAST EXTENDING SOUTH
SOUTHWEST TO THE VICINITY OF THE SOUTHEAST UNITED STATES THE
BUILDING UPPER LEVEL RIDGE TO OUR WEST SHOULD STRENGTHEN A NORTH-
SOUTH SURFACE RIDGE FROM QUEBEC SOUTHWARD ALONG THE EASTERN
SEABOARD. THIS WEATHER PATTERN USUALLY SIGNALS A DRY AND SLIGHTLY
COOLER THAN NORMAL CONDITIONS FOR CENTRAL NORTH CAROLINA.
FOR WEDNESDAY THROUGH THURSDAY...MEDIUM RANGE GUIDANCE IN
REASONABLY GOOD AGREEMENT DEPICTING THE UPPER LEVEL RIDGE CLOSING
OFF AND DRIFTING SLOWLY EAST ACROSS NEW ENGLAND. THIS IS TURN
DEVELOPS A WEAK CLOSED UPPER LEVEL LOW OVER THE SOUTHEAST UNITED
STATES WHICH INDUCES SURFACE CYCLOGENESIS OFF THE GA/SC COAST.
WHILE NOT OUT OF THE REALM OF POSSIBILITIES...THIS TYPE OF PATTERN
IS A BIT ANOMALOUS TO THIS TIME OF YEAR AND THE UPPER LEVEL LOW IS
RATHER WEAK. WHILE BAROCLINICITY MAY INCREASE OFFSHORE WITH THE
COOLER AIR ASSOCIATED WITH THE BUILDING RIDGE CROSSING THE WARM
WATERS LEADING TO SOME CYCLOGENESIS...MODELS MAY BE UNDERPLAYING
THE DRY AIR AND SUBSIDENCE ASSOCIATED WITH THE SURFACE RIDGE OVER
CENTRAL NORTH CAROLINA. THUS...PREFER TO KEEP WEDNESDAY INTO
THURSDAY DRY WITH TEMPERATURES REMAINING SLIGHTLY BELOW NORMAL.
THE CONTRAST BETWEEN THE SURFACE RIDGE AND THE CONDITIONS OFFSHORE
MAY LEAD TO ENHANCE LOW LEVEL NORTHEAST FLOW OVER THE EASTERN
COUNTIES. FOR NOW...WILL MAINTAIN NEAR SURFACE WINDS THU AROUND
15 KNOTS.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 2 AM FRIDAY...
LOW LEVEL RIDGING BUILDING IN FROM THE NORTHEAST COMBINED WITH A
WEAK LOW AND SFC TROUGH OVER THE WESTERN ATLANTIC HAS TIGHTENED THE
LOW LEVEL GRADIENT ACROSS EASTERN NORTH CAROLINA. LOCAL RADAR WIND
PROFILES AND THE RALEIGH AIR QUALITY PROFILE CONFIRM THAT WINDS HAVE
INCREASE TO 25-35KT IN THE 1-2 KFT LAYER FROM RDU SOUTH AND EAST.
MEANWHILE...THE NOCTURNAL INVERSION HAS KEPT WINDS JUST AROUND 5 KT
AT THE SFC. THIS IS CURRENTLY RESULTING IN LOW LEVEL WIND SHEAR AT
RDU/FAY/RWI AND SHOULD PERSIST THROUGH DAYBREAK. THE GRADIENT FLOW
IS 5-10 KT WEAKER AT GSO/INT...THUS LLWS HAS NOT BEEN INCLUDED IN
THE TAFS THERE. THE OTHER CONCERN FOR THE DAYBREAK HOURS IS THE
ADVECTION OF LOW LEVEL MOISTURE UNDER THE NORTHEAST WIND FLOW. VFR
CIGS (GENERALLY 5-7 KFT) HAVE DEVELOPED IN CENTRAL VIRGINIA.
MEANWHILE...ADDITIONAL LOWER STRATUS WITH BASES AROUND 2 KFT HAS
DEVELOPED JUST OFFSHORE THE SE VA/NE NC COASTS. THIS MOISTURE SHOULD
CONTINUE TO ADVECT SOUTHWESTWARD AND MAY RESULT IN LOW END MVFR CIGS
AT RDU/RWI/FAY BETWEEN 10-13Z.
SCATTERED TO BROKEN VFR STRATOCUMULUS IS EXPECTED TO LINGER THROUGH
MUCH OF THE DAY UNDER THE PERSISTENT MOIST NORTHEAST FLOW. CLOUDS
SHOULD DIMINISH IN THE EVENING AS THE HIGHEST LOW LEVEL MOISTURE
MOVES FURTHER SOUTH AND WEST. WINDS ARE APT TO BE BREEZY
TODAY...PARTICULARLY AT THE EASTERN TERMINALS WHERE THE GRADIENT IS
TIGHTER. SUSTAINED WINDS EXPECTED TO BE 10-15 KT ACROSS THE ENTIRE
REGION...WITH GUSTS OF 20 KT OR SLIGHTLY HIGHER AT RDU/FAY/RWI.
WHILE GUSTS WILL DIMINISH CLOSE TO SUNSET...SUSTAINED WINDS WILL
STAY CLOSE TO 10 KT IN THE EAST DUE TO THE PERSISTENT STRONG SFC
PRESSURE GRADIENT. ANOTHER EPISODE OF LLWS POSSIBLE EARLY SATURDAY
MORNING IF SFC WINDS DECREASE SUBSTANTIALLY.
ANOTHER PERIOD OF CLOUDINESS MAY OCCUR SATURDAY AND SATURDAY NIGHT
AS MOISTURE POOLS ALONG A TROUGH POSITIONED ALONG THE COAST. A
SECOND PERIOD OF LOW STRATUS IS EXPECTED MONDAY NIGHT. OTHERWISE VFR
CONDITIONS EXPECTED.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS/HARTFIELD
AVIATION...JFB
000
FXUS62 KILM 190545
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
145 AM EDT FRI SEP 19 2008
.SYNOPSIS...
HIGH PRESSURE ACROSS THE NORTHEAST WILL RIDGE INTO THE CAROLINAS
INTO THE WEEKEND AND BRING COOLER THAN NORMAL TEMPERATURES TO THE
REGION. A TROUGH OF LOW PRESSURE WILL DEVELOP OFFSHORE AND MOVE
CLOSE ENOUGH TO THE AREA TO INCREASE THE CHANCE OF SHOWERS LATE IN
THE WEEKEND AND INTO EARLY NEXT WEEK...MAINLY ALONG THE COASTAL
COUNTIES. TEMPERATURES WILL REMAIN SLIGHTLY BELOW NORMAL THROUGH THE
PERIOD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 9 PM THURSDAY...LATEST SAT IMAGERY 11-3.9 MICRON... INDICATES
CLOUDINESS WELL OFFSHORE ASSOCIATED WITH THE SFC BAROCLINIC ZONE
OTHERWISE KNOWN AS THE STALLED FRONTAL BOUNDARY...WILL NOT AFFECT
THE ILM CWA. THE STRATOCU CLOUDS OVER THE ATL WATERS CLOSER TO THE
CAROLINA COASTS DEPICTED BY SAT IMAGERY...IS MAINLY ASSOCIATED
WITHIN THE LOW LEVEL NE FLOW. TRAJECTORIES WITH THIS FLOW INDICATE
SOME OF THESE CLOUDS COULD SPORADICALLY AFFECT SOUTHEAST GEORGETOWN
COUNTY THRUOUT THE NITE. AS A RESULT...CLEAR SKIES TO PREVAIL
OVERNITE ACROSS ALL AREAS...WITH MSTLY CLEAR INDICATED FOR
GEORGETOWN CNTY.
A SOMEWHAT TIGHTENED SFC PRESSURE GRADIENT TO EXIST OVER THE ILM CWA
OVERNIGHT...TIGHTER AS YOU MOVE CLOSER TO THE COAST AND OVER THE
ADJACENT ATLANTIC WATERS. THIS IN RESPONSE TO THE PRESSURE GRADIENT
BETWEEN THE 1020+ SFC HIGH ACROSS SOUTHERN NEW ENGLAND...AND A
DEVELOPING SFC LOW WELL OFFSHORE FROM GA-SC ALONG THE STALLED SFC
BOUNDARY. UNLESS A STRONG SFC BASED INVERSION DEVELOPS
OVERNITE...WOULD THINK N TO NE WINDS WOULD ATLEAST STAY IN THAT 5
MPH RANGE...HIER AS YOU MOVE TO THE IMMEDIATE COAST. CURRENT MIN
TEMP FCST BASED ON A MIXED BNDRY LAYER AND WILL THERE4 LEAVE AS IS.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...NOT MUCH CHANGE FROM THE PREVIOUS FORECAST
WITH HIGH ENTRENCHED ACROSS THE NORTHEAST AND RIDGING INTO THE
CAROLINAS WE CAN EXPECT A SUNNY DAY ACROSS THE REGION ON FRIDAY
WITH AN INCREASE IN CLOUDS ON SATURDAY ESPECIALLY ALONG THE
COASTAL COUNTIES AS TROUGH OFFSHORE MOVES TO THE WEST AND MODELS
STILL SHOWING INCREASE IN RH VALUES. HAVE KEPT THE PREVIOUS
MENTIONED SHOWERS ALONG THE COASTAL COUNTIES AND SLIGHT CHANCE
ACROSS THE ADJACENT INLAND COUNTIES. TEMPS TO RUN SLIGHTLY BELOW
NORMAL FOR THE NEXT FEW DAYS AS NE WIND FLOW ACROSS THE REGION
KEEPS US COOLER THAN NORMAL.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...A 500 MB SPLIT FLOW ACROSS THE EASTERN HALF
OF THE U.S. WILL BRING THE POSSIBILITY OF AN EXTENDED PERIOD OF
UNSETTLED WEATHER TO THE CAROLINAS. UPPER LEVEL RIDGING ACROSS THE
OHIO VALLEY ON SUNDAY WILL AMPLIFY INTO A CLOSED HIGH OVER THE GREAT
LAKES TUESDAY INTO WEDNESDAY. BOTH THE ECMWF AND THE GFS NOW
INDICATE VORTICITY SOUTH OF THE UPPER RIDGE WILL CONSOLIDATE INTO AN
UPPER LOW OVER THE CAROLINAS WEDNESDAY INTO THURSDAY. THIS LOOKS
LIKE A REX BLOCK ON 500 MB PROGS...BUT SHOULD BE TOO PROGRESSIVE A
PATTERN TO TECHNICALLY CALL A BLOCK.
AT THE SURFACE A STALLED FRONT JUST OFFSHORE WILL DO LITTLE SUNDAY
THROUGH TUESDAY. COOL AND DRY NORTHEAST LOW-LEVEL FLOW ON THE INLAND
SIDE OF THIS BOUNDARY WILL KEEP TEMPERATURES A FEW DEGREES BELOW
NORMAL. ONCE THE UPPER LOW FORMS ON WEDNESDAY...SURFACE LOW PRESSURE
WILL BEGIN TO DEVELOP ALONG THE FRONT OFFSHORE. A STRENGTHENING
EASTERLY (ONSHORE) FLOW AROUND THE UPPER LOW SHOULD ADVECT DEEP
LAYER MOISTURE BACK INTO THE AREA LATE WEDNESDAY INTO THURSDAY.
AN INTERESTING ASPECT TO CONSIDER WITH THIS SCENARIO IS HOW MANY
TROPICAL CHARACTERISTICS A SLOW-MOVING FRONTAL LOW COULD PICK UP
WHILE OVER THE GULF STREAM FOR SEVERAL DAYS. THE HPC EXTENDED
DISCUSSION GIVES MORE DETAILS ABOUT POSSIBLE IMPACTS SHOULD AN
SUBTROPICAL TRANSITION OCCUR. MORE MUNDANE TO CONSIDER...BUT
SITUATIONS SUCH AS THESE OFTEN WRAP CONSIDERABLE DRY AIR IN FROM THE
NORTH WHICH LIMITS THE WEST AND NORTHWESTWARD PENETRATION OF RAIN.
THE UPPER LOW INLAND MAY MITIGATE THIS SOME...BUT MANY POSSIBILITIES
REMAIN OPEN. SINCE THIS IS STILL A 6 AND 7 DAY FORECAST WE HAVE ONLY
RAISED POPS 10-20% ABOVE CLIMATOLOGY UNTIL DETAILS CAN GET HAMMERED
OUT OVER THE NEXT FEW DAYS.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS THROUGH THE FORECAST PERIOD. TIGHT GRADIENT SETS UP
FOR FRIDAY. KEPT THE WINDS UP AS BUFKIT SHOWS STRONG WINDS AT THE
BOUNDARY LAYER...WITH THINGS MIXING PRETTY GOOD A COUPLE OF HOURS
AFTER DAYBREAK. WILL BITE ON THE STRATA CU DECK BEGINNING FRIDAY
AFTERNOON. SHOULD REMAIN VFR. WINDS WILL DIMINISH SOMEWHAT TOWARD
THE END OF THE 24 HOUR FORECAST PERIOD.
OUTLOOK THROUGH MONDAY...QUITE A BIT OF UNCERTAINTY SATURDAY THROUGH
TUESDAY. CONTINUED NORTHEAST FLOW...WITH LOW PRESSURE POSSIBLY
SETTING UP CLOSE ENOUGH TO SHORE TO AFFECT COASTAL TERMINALS WITH
LOWER CEILINGS AND RAIN SATURDAY/SUNDAY. IF THE LOW SETS UP FURTHER
OFFSHORE...LOOK FOR VFR CONDITIONS...HOWEVER WINDY CONDITIONS ARE
EXPECTED SATURDAY...MONDAY AND TUESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 9 PM THURSDAY...SFC RIDGING ACROSS THE AREA WATERS EMINATING
FROM A 1020+ HIGH CENTERED OVER SOUTHERN NEW ENGLAND...WILL INTERACT
WITH A SFC LOW TRYING TO DEVELOP ALONG A STALLED BOUNDARY WELL
OFFSHORE FROM THE SE U.S. COAST. THIS INTERACTION WILL RESULT IN A
TIGHTENING OF THE SFC PRESSURE GRADIENT ACROSS THE WATERS LATER
TONIGHT THROUGH MUCH OF THE SHORT TERM PERIOD. AS A RESULT...N-NE
SUSTAINED WINDS WILL FURTHER INCREASE TO SCA CRITERIA AROUND OR JUST
AFTER SUNRISE FRIDAY. SEAS WILL PRIMARILY BE COMPRISED OF THE WIND
DRIVEN LOW PERIOD WASH MACHINE TYPE WAVES...AND WILL ALSO INCREASE
OVERNITE TO JUST BELOW SCA CRITERIA BY SUNRISE. AS USUAL...THE N TO
NE WINDS WILL CAUSE A RANGE OF SEAS DUE TO THE CONFIGURATION OF THE
COASTLINE...AND THE LACK OF ANY TYPE OR SIZE TO AN ONSHORE SWELL
COMPONENT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 6 PM EDT THIS
AFTERNOON FOR AMZ250-252-254-256.
&&
$$
SYNOPSIS...MAC
NEAR TERM...MBB
SHORT TERM...MAC
LONG TERM...TRA
AVIATION...DL/III
000
FXUS62 KILM 190243
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
955 PM EDT THU SEP 18 2008
.SYNOPSIS...
HIGH PRESSURE ACROSS THE NORTHEAST WILL RIDGE INTO THE CAROLINAS
INTO THE WEEKEND AND BRING COOLER THAN NORMAL TEMPERATURES TO THE
REGION. A TROUGH OF LOW PRESSURE WILL DEVELOP OFFSHORE AND MOVE
CLOSE ENOUGH TO THE AREA TO INCREASE THE CHANCE OF SHOWERS LATE IN
THE WEEKEND AND INTO EARLY NEXT WEEK...MAINLY ALONG THE COASTAL
COUNTIES. TEMPERATURES WILL REMAIN SLIGHTLY BELOW NORMAL THROUGH THE
PERIOD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 9 PM THURSDAY...LATEST SAT IMAGERY 11-3.9 MICRON... INDICATES
CLOUDINESS WELL OFFSHORE ASSOCIATED WITH THE SFC BAROCLINIC ZONE
OTHERWISE KNOWN AS THE STALLED FRONTAL BOUNDARY...WILL NOT AFFECT
THE ILM CWA. THE STRATOCU CLOUDS OVER THE ATL WATERS CLOSER TO THE
CAROLINA COASTS DEPICTED BY SAT IMAGERY...IS MAINLY ASSOCIATED
WITHIN THE LOW LEVEL NE FLOW. TRAJECTORIES WITH THIS FLOW INDICATE
SOME OF THESE CLOUDS COULD SPORADICALLY AFFECT SOUTHEAST GEORGETOWN
COUNTY THRUOUT THE NITE. AS A RESULT...CLEAR SKIES TO PREVAIL
OVERNITE ACROSS ALL AREAS...WITH MSTLY CLEAR INDICATED FOR
GEORGETOWN CNTY.
A SOMEWHAT TIGHTENED SFC PRESSURE GRADIENT TO EXIST OVER THE ILM CWA
OVERNIGHT...TIGHTER AS YOU MOVE CLOSER TO THE COAST AND OVER THE
ADJACENT ATLANTIC WATERS. THIS IN RESPONSE TO THE PRESSURE GRADIENT
BETWEEN THE 1020+ SFC HIGH ACROSS SOUTHERN NEW ENGLAND...AND A
DEVELOPING SFC LOW WELL OFFSHORE FROM GA-SC ALONG THE STALLED SFC
BOUNDARY. UNLESS A STRONG SFC BASED INVERSION DEVELOPS
OVERNITE...WOULD THINK N TO NE WINDS WOULD ATLEAST STAY IN THAT 5
MPH RANGE...HIER AS YOU MOVE TO THE IMMEDIATE COAST. CURRENT MIN
TEMP FCST BASED ON A MIXED BNDRY LAYER AND WILL THERE4 LEAVE AS IS.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...NOT MUCH CHANGE FROM THE PREVIOUS FORECAST
WITH HIGH ENTRENCHED ACROSS THE NORTHEAST AND RIDGING INTO THE
CAROLINAS WE CAN EXPECT A SUNNY DAY ACROSS THE REGION ON FRIDAY
WITH AN INCREASE IN CLOUDS ON SATURDAY ESPECIALLY ALONG THE
COASTAL COUNTIES AS TROUGH OFFSHORE MOVES TO THE WEST AND MODELS
STILL SHOWING INCREASE IN RH VALUES. HAVE KEPT THE PREVIOUS
MENTIONED SHOWERS ALONG THE COASTAL COUNTIES AND SLIGHT CHANCE
ACROSS THE ADJACENT INLAND COUNTIES. TEMPS TO RUN SLIGHTLY BELOW
NORMAL FOR THE NEXT FEW DAYS AS NE WIND FLOW ACROSS THE REGION
KEEPS US COOLER THAN NORMAL.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...A 500 MB SPLIT FLOW ACROSS THE EASTERN HALF
OF THE U.S. WILL BRING THE POSSIBILITY OF AN EXTENDED PERIOD OF
UNSETTLED WEATHER TO THE CAROLINAS. UPPER LEVEL RIDGING ACROSS THE
OHIO VALLEY ON SUNDAY WILL AMPLIFY INTO A CLOSED HIGH OVER THE GREAT
LAKES TUESDAY INTO WEDNESDAY. BOTH THE ECMWF AND THE GFS NOW
INDICATE VORTICITY SOUTH OF THE UPPER RIDGE WILL CONSOLIDATE INTO AN
UPPER LOW OVER THE CAROLINAS WEDNESDAY INTO THURSDAY. THIS LOOKS
LIKE A REX BLOCK ON 500 MB PROGS...BUT SHOULD BE TOO PROGRESSIVE A
PATTERN TO TECHNICALLY CALL A BLOCK.
AT THE SURFACE A STALLED FRONT JUST OFFSHORE WILL DO LITTLE SUNDAY
THROUGH TUESDAY. COOL AND DRY NORTHEAST LOW-LEVEL FLOW ON THE INLAND
SIDE OF THIS BOUNDARY WILL KEEP TEMPERATURES A FEW DEGREES BELOW
NORMAL. ONCE THE UPPER LOW FORMS ON WEDNESDAY...SURFACE LOW PRESSURE
WILL BEGIN TO DEVELOP ALONG THE FRONT OFFSHORE. A STRENGTHENING
EASTERLY (ONSHORE) FLOW AROUND THE UPPER LOW SHOULD ADVECT DEEP
LAYER MOISTURE BACK INTO THE AREA LATE WEDNESDAY INTO THURSDAY.
AN INTERESTING ASPECT TO CONSIDER WITH THIS SCENARIO IS HOW MANY
TROPICAL CHARACTERISTICS A SLOW-MOVING FRONTAL LOW COULD PICK UP
WHILE OVER THE GULF STREAM FOR SEVERAL DAYS. THE HPC EXTENDED
DISCUSSION GIVES MORE DETAILS ABOUT POSSIBLE IMPACTS SHOULD AN
SUBTROPICAL TRANSITION OCCUR. MORE MUNDANE TO CONSIDER...BUT
SITUATIONS SUCH AS THESE OFTEN WRAP CONSIDERABLE DRY AIR IN FROM THE
NORTH WHICH LIMITS THE WEST AND NORTHWESTWARD PENETRATION OF RAIN.
THE UPPER LOW INLAND MAY MITIGATE THIS SOME...BUT MANY POSSIBILITIES
REMAIN OPEN. SINCE THIS IS STILL A 6 AND 7 DAY FORECAST WE HAVE ONLY
RAISED POPS 10-20% ABOVE CLIMATOLOGY UNTIL DETAILS CAN GET HAMMERED
OUT OVER THE NEXT FEW DAYS.
&&
.AVIATION /00Z THURSDAY THROUGH TUESDAY/...
VFR CONDITIONS THROUGH THE FORECAST PERIOD. TIGHT GRADIENT SETS UP
FOR FRIDAY. BUMPED THE WINDS UP A BIT AS BUFKIT SHOWS STRONG WINDS
AT THE BOUNDARY LAYER...WITH THINGS MIXING PRETTY GOOD A COUPLE OF
HOURS AFTER DAYBREAK. WINDS WILL DIMINISH SOMEWHAT TOWARD THE END OF
THE 24 HOUR FORECAST PERIOD.
OUTLOOK THROUGH MONDAY...QUITE A BIT OF UNCERTAINTY SATURDAY THROUGH
TUESDAY. CONTINUED NORTHEAST FLOW...WITH LOW PRESSURE POSSIBLY
SETTING UP CLOSE ENOUGH TO SHORE TO AFFECT COASTAL TERMINALS WITH
LOWER CEILINGS AND RAIN SATURDAY/SUNDAY. IF THE LOW SETS UP FURTHER
OFFSHORE...LOOK FOR VFR CONDITIONS...HOWEVER WINDY CONDITIONS ARE
EXPECTED SATURDAY...MONDAY AND TUESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 9 PM THURSDAY...SFC RIDGING ACROSS THE AREA WATERS EMINATING
FROM A 1020+ HIGH CENTERED OVER SOUTHERN NEW ENGLAND...WILL INTERACT
WITH A SFC LOW TRYING TO DEVELOP ALONG A STALLED BOUNDARY WELL
OFFSHORE FROM THE SE U.S. COAST. THIS INTERACTION WILL RESULT IN A
TIGHTENING OF THE SFC PRESSURE GRADIENT ACROSS THE WATERS LATER
TONIGHT THROUGH MUCH OF THE SHORT TERM PERIOD. AS A RESULT...N-NE
SUSTAINED WINDS WILL FURTHER INCREASE TO SCA CRITERIA AROUND OR JUST
AFTER SUNRISE FRIDAY. SEAS WILL PRIMARILY BE COMPRISED OF THE WIND
DRIVEN LOW PERIOD WASH MACHINE TYPE WAVES...AND WILL ALSO INCREASE
OVERNITE TO JUST BELOW SCA CRITERIA BY SUNRISE. AS USUAL...THE N TO
NE WINDS WILL CAUSE A RANGE OF SEAS DUE TO THE CONFIGURATION OF THE
COASTLINE...AND THE LACK OF ANY TYPE OR SIZE TO AN ONSHORE SWELL
COMPONENT.
&&
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...WILL KEEP THE MENTION OF SCA FOR FRIDAY AS
NE FLOW INCREASES ACROSS THE OFFSHORE WATERS AND SEAS KICK UP TO
6-8 FEET WITH NEARSHORE SEAS RUNNING 2-5. WINDS WILL RUN BETWEEN
20 TO 25 KTS WITH GUSTS TO 30 KTS. CONDITIONS WILL START TO
IMPROVE BY SATURDAY AFTERNOON WITH WINDS ABATING A BIT AND SEAS
WILL COME DOWN AS WELL. WITH OFFSHORE TROUGH MOVING TO THE WEST ON
SATURDAY WILL KEEP THE MENTION OF CHANCE OF SHOWERS BASICALLY
THROUGH THE PERIOD.
&&
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 PM THURSDAY...AS OF 3 PM WEDNESDAY...A STALLED FRONT WILL
REMAIN OFFSHORE SUNDAY THROUGH MONDAY. A LARGE AND UNSEASONABLY
STRONG HIGH PRESSURE OVER NEW ENGLAND WILL SLOWLY RIDGE SOUTH AND
PRODUCE A PERIOD OF MODERATE NORTHEASTERLY WINDS ACROSS THE
WATERS. WINDS ON SUNDAY 10-15 KT WILL INCREASE CLOSER TO 20 KT BY
MONDAY NIGHT AS THE GRADIENT TIGHTENS FURTHER.
BEYOND THE SCOPE OF OUR 5-DAY FORECAST BUT STILL WORTH A MENTION...
MODELS ARE BECOMING MORE INSISTENT THAT A NOR`EASTER OR PERHAPS A
HYBRID/SUBTROPICAL SYSTEM MAY DEVELOP ALONG THE CAROLINA COAST NEXT
WEDNESDAY OR THURSDAY. THIS IS STILL 6 AND 7 DAYS OUT BUT IS WORTHY
OF CONSIDERATION FOR PLANNING PURPOSES GIVEN THE POTENTIAL IMPACT ON
THE MARINE COMMUNITY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT FRIDAY FOR
AMZ250- 252-254-256.
&&
$$
SYNOPSIS...CAROPOLO
NEAR TERM...HOEHLER
SHORT TERM...CAROPOLO
LONG TERM...ARMSTRONG
AVIATION...LOEWENTHAL
000
FXUS62 KRAH 190232
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1032 PM EDT THU SEP 18 2008
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL EXTEND DOWN THE EAST COAST THROUGH THE
WEEKEND...BRINGING COOL AND DRY CONDITIONS TO CENTRAL NORTH CAROLINA.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 1030 PM THURSDAY...
DRY AND COMFORTABLY COOL CONDITIONS EXPECTED OVERNIGHT. A 1031 MB
SURFACE HIGH CENTERED OVER SOUTHERN QUEBEC THIS EVENING WILL
CONTINUE TO BUILD SOUTHWARD INTO OUR REGION TONIGHT. THE CURRENT
CLEAR SKIES SHOULD REMAIN SO MOST OF THE NIGHT... AND ALLOW
TEMPERATURES TO DIP TO BETWEEN 54 AND 59 DEGREES FOR OVERNIGHT LOW
TEMPERATURES. HOWEVER... SOME CLOUD COVER MAY INCREASE FROM THE
NORTH JUST PRIOR TO SUNRISE... AS MOISTURE CURRENTLY CENTERED AROUND
5 THSD FT INVOF A WEAK SURFACE TO H85 BACKDOOR FRONT OVER THE
DELMARVA THIS EVENING SPREADS SOUTHWESTWARD. THIS MAY RESULT IN A
PERIOD OF SCATTERED TO BROKEN STRATOCUMULUS/STRATUS SPREADING INTO
OUR AREA ON NORTHEAST FLOW BY DAYBREAK. IN FACT... THE MODELS
SUGGEST A SECOND SATURATED (STRATUS) LAYER MAY DEVELOP BETWEEN 1 AND
2 THSD FEET... AS THE LOW LEVELS COOL AND THE BAND OF MOISTURE
ARRIVES. THIS POSSIBILITY IS SUPPORTED BY THE UPSTREAM WALLOPS
ISLAND RAOB THAT REVEALS A SECONDARY INVERSION AND RELATIVELY MOIST
LAYER ALREADY AROUND 1200 FT.
A NOCTURNAL LOW LEVEL JET HAS ALSO DEVELOPED ABOVE THE DECOUPLED
SURFACE LAYER OVER THE COASTAL PLAIN OF NC PER RALNC AIR QUALITY
PROFILER AND KMHX VWP WIND DATA. IN FACT... THEY INDICATE WINDS
AROUND 2 THSD FT HAVE INCREASED TO BETWEEN 25 AND 35 KNOTS OVER THE
EASTERN THIRD OF THE STATE.... HIGHEST ALONG THE COAST. THIS LLJ IS
EXPECTED TO PERSIST IN THESE AREAS OVERNIGHT... AND MAY RESULTANTLY
AFFECT AVIATION INTERESTS - SEE AVIATION AFD BELOW. -MWS
AS OF 215 PM THURSDAY...
FOR FRIDAY... THE PRESSURE GRADIENT WILL CONTINUE TO TIGHTEN AS THE
SURFACE HIGH MOVES EAST WITH THE BAROCLINIC ZONE STILL SITTING OFF
THE COAST. AS THE LOW LEVEL INVERSION MIXES OUT IN THE MORNING... WE
SHOULD SEE PREVAILING NORTHEAST WINDS QUICKLY JUMP UP TO 10-20 MPH
WITH SOME GUSTS TO 25 MPH. OTHERWISE... THE AFOREMENTIONED BATCH OF
CLOUDS SHOULD CONTINUE MOVING SOUTHWEST TO THE SOUTHERN CWA FRIDAY
MORNING... LEAVING MOSTLY SUNNY SKIES... ALTHOUGH A FEW FLAT
CONVECTIVE CUMULUS MAY POP UP THROUGH THE AFTERNOON. WITH
THICKNESSES EXPECTED TO BE ONLY MARGINALLY LOWER THAN TODAY...
TEMPERATURES SHOULD FOLLOW SUIT... WITH HIGHS IN THE IN THE 76-81
RANGE. -GIH
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 245 PM THURSDAY...
FRIDAY NIGHT THROUGH SATURDAY...DRY AIR SURFACE RIDGE WILL STRETCH
FROM THE SOUTHERN NEW ENGLAND COAST TO THE WESTERN CAROLINAS.
MEANWHILE AN AREA OF LOW PRESSURE WILL MEANDER OFF CAPE FEAR. THE
DIFFERENCE IN PRESSURE BETWEEN THE RIDGE AND THE LOW OFFSHORE WILL
CREATE A STEADY NE FLOW OVER THE AREA WITH THE STEADY/BREEZY WINDS
EXPECTED EAST OF HIGHWAY 1. THIS CIRCULATION PATTERN WILL ADVECT
POCKETS OF MOISTURE IN THE LOWEST 10000FT FEET. THIS WILL RESULT IN
PERIODS OF CLOUDINESS...AGAIN MAINLY EAST OF HIGHWAY 1. MECHANISMS
FOR LIFT TO GENERATE PRECIPITATION ARE ABSENT SO DO NOT EXPECT ANY
PRECIPITATION THROUGH THE PERIOD.
THE LOW LEVEL NE FLOW WILL RESULT IN MAX TEMPS SLIGHTLY
COOLER THAN NORMAL. THICKNESSES WITH FULL TO PARTIAL SUN SUPPORT MAX
TEMPS MAINLY IN THE MID 70S. A STEADY NE WIND FRIDAY NIGHT WILL KEEP
THE BOUNDARY LAYER WELL MIXED. THIS SHOULD RESULT IN TEMPS A COUPLE
OF DEGREES WARMER THAN NORMALLY OCCUR WHEN THE WINDS DECOUPLE AT THE
SURFACE. USED A BLAND OF MOS TEMP GUIDANCE FOR MIN TEMP FORECAST FRI
NIGHT/SATURDAY MORNING.
SATURDAY NIGHT THROUGH SUNDAY NIGHT...NOT MUCH CHANGE IN THE
SENSIBLE WEATHER THROUGH THIS PERIOD. SURFACE RIDGE AXIS WILL
CONTINUE OVER THE WESTERN CAROLINAS WHILE SURFACE LOW OFFSHORE OF
CAPE FEAR IS FORECAST TO WEAKEN/DISSIPATE. RELAXING OF PRESSURE
GRADIENT WILL LEAD TO A WEAKER WIND FIELD. THE WEAKER NORTHEAST
FETCH WILL RESULT IN LESS CLOUDINESS BELOW 10000 FEET. HOWEVER...MAY
SEE SOME ENHANCEMENT OF HIGH LEVEL CLOUDINESS AS FLOW ALOFT BACKS AND
STRENGTHENS IN RESPONSE TO A MINOR SHORT WAVE THAT SHEARS NORTHEAST
ACROSS THE OHIO VALLEY. THUS EXPECT A CONTINUATION OF PARTLY CLOUDY
SKIES.
THICKNESSES SUNDAY REBOUND 10 TO 13 METERS FROM SATURDAY THICKNESSES.
THE MODERATING AIR MASS COUPLED WITH A WEAKER NE SURFACE FLOW
SHOULD TRANSLATES TO MAX TEMPERATURES 3 TO 5 DEGREES WARMER SUNDAY
COMPARED TO SATURDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 245 PM THURSDAY...
MONDAY THROUGH WEDNESDAY...UPPER LEVEL RIDGE WILL BUILD FROM TX
INTO THE GREAT LAKES/SOUTHERN ONTARIO THROUGH THIS PERIOD WITH
BAGGY UPPER LEVEL TROUGH OFF THE NEW ENGLAND COAST EXTENDING SOUTH
SOUTHWEST TO THE VICINITY OF THE SOUTHEAST UNITED STATES THE
BUILDING UPPER LEVEL RIDGE TO OUR WEST SHOULD STRENGTHEN A NORTH-
SOUTH SURFACE RIDGE FROM QUEBEC SOUTHWARD ALONG THE EASTERN
SEABOARD. THIS WEATHER PATTERN USUALLY SIGNALS A DRY AND SLIGHTLY
COOLER THAN NORMAL CONDITIONS FOR CENTRAL NORTH CAROLINA.
FOR WEDNESDAY THROUGH THURSDAY...MEDIUM RANGE GUIDANCE IN
REASONABLY GOOD AGREEMENT DEPICTING THE UPPER LEVEL RIDGE CLOSING
OFF AND DRIFTING SLOWLY EAST ACROSS NEW ENGLAND. THIS IS TURN
DEVELOPS A WEAK CLOSED UPPER LEVEL LOW OVER THE SOUTHEAST UNITED
STATES WHICH INDUCES SURFACE CYCLOGENESIS OFF THE GA/SC COAST.
WHILE NOT OUT OF THE REALM OF POSSIBILITIES...THIS TYPE OF PATTERN
IS A BIT ANOMALOUS TO THIS TIME OF YEAR AND THE UPPER LEVEL LOW IS
RATHER WEAK. WHILE BAROCLINICITY MAY INCREASE OFFSHORE WITH THE
COOLER AIR ASSOCIATED WITH THE BUILDING RIDGE CROSSING THE WARM
WATERS LEADING TO SOME CYCLOGENESIS...MODELS MAY BE UNDERPLAYING
THE DRY AIR AND SUBSIDENCE ASSOCIATED WITH THE SURFACE RIDGE OVER
CENTRAL NORTH CAROLINA. THUS...PREFER TO KEEP WEDNESDAY INTO
THURSDAY DRY WITH TEMPERATURES REMAINING SLIGHTLY BELOW NORMAL.
THE CONTRAST BETWEEN THE SURFACE RIDGE AND THE CONDITIONS OFFSHORE
MAY LEAD TO ENHANCE LOW LEVEL NORTHEAST FLOW OVER THE EASTERN
COUNTIES. FOR NOW...WILL MAINTAIN NEAR SURFACE WINDS THU AROUND
15 KNOTS.
&&
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
AS OF 905 PM...
WIND SPEEDS ABOVE THE BOUNDARY LAYER ARE BEGINNING TO INCREASE AS
THIS AIR LOSES THE INFLUENCE OF FRICTION WITH THE SURFACE. THE
PRESSURE GRADIENT IS TIGHTEST TO THE EAST AND THE FORECAST OF LOW
LEVEL WIND SHEAR IN THE EAST TOWARD MORNING IS RETAINED.
CLOUDS IN VIRGINIA HAVE LARGELY DISSIPATED. THE MOISTURE
ASSOCIATED WITH THESE CLOUDS WILL ADVANCE INTO NORTH CAROLINA ON
NORTHEAST FLOW TONIGHT AND ADVECT WEST TOWARD THE MOUNTAINS DURING
THE MORNING. EXPECT MOSTLY SCATTERED CLOUDS...BUT SOME LOW VFR
CEILINGS ARE POSSIBLE DURING THE MORNING HOURS.
A LOW PRESSURE CENTER OFF THE CAROLINA COAST WILL DRIFT WEST AND
CONTINUE TO KEEP A SIGNIFICANT PRESSURE GRADIENT OVER NORTH
CAROLINA. LOW LEVEL WIND SHEAR IS LIKELY TO BE A THREAT AGAIN
FRIDAY NIGHT.
ANOTHER PERIOD OF CLOUDINESS MAY OCCUR SATURDAY AND SATURDAY NIGHT
AS MOISTURE POOLS ALONG A TROUGH POSITIONED ALONG THE COAST.
A SECOND PERIOD OF LOW STRATUS IS EXPECTED MONDAY NIGHT. OTHERWISE
VFR CONDITIONS EXPECTED.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS/HARTFIELD
000
FXUS62 KMHX 190124
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
920 PM EDT THU SEP 18 2008
.SYNOPSIS...
STRONG HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE NE STATES
THROUGH FRIDAY AND MOVE E THROUGH SATURDAY...AS A SLOW MOVING
FRONTAL SYSTEM REMAINS OFFSHORE. AN EVEN STRONGER AREA OF HIGH
PRESSURE IS EXPECTED TO BUILD INTO THE AREA EARLY TO MID NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
MINOR GRID UPDATE FOR SKY COVER EARLY THIS EVENING...OTRW FCST ON
TRACK AND NO ZFP UPDATE PLANNED. CAA WILL PRODUCE HIGH AND DRY
CONDITIONS MOST AREAS OVERNIGHT. STLT IMAGERY INDICATES SOME SCU OFF
NRN OUTER BANKS WHICH WILL SPREAD IN OVERNIGHT WITH NE WINDS. TEMPS
OK.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
MAIN STORY THIS FORECAST PERIOD WILL BE COASTAL IMPACTS FROM THE
LONG FETCH OF STRONG NE/ENE WINDS SETTING UP OFF THE EAST
COAST...ASSOCIATED WITH THE INTERACTION BETWEEN HIGH PRESSURE MOVING
E FROM NEW ENGLAND AND THE WAVY FRONTAL SYSTEM OFFSHORE. WE ARE
EXPECTING SOME MINOR OCEAN OVERWASH AND BEACH EROSION FROM THIS
PATTERN AT NORMAL PRONE AREAS IN THE OUTER BANKS (PORTIONS OF HWY 12
NEAR KITTY HAWK/PEA ISLAND/RODANTHE)...IN ADDITION TO A VERY HIGH
RISK OF RIP CURRENTS AND DANGEROUS SURF CONDITIONS. THESE IMPACTS
WILL BY FAR BE FELT THE MOST AT EAST FACING BEACHES ALONG THE OUTER
BANKS AND A MUCH LESSER EXTENT AT SOUTH FACING BEACHES DUE TO THE
PREVAILING NE WIND AND WAVE DIRECTION. AT THIS POINT WINDS ARE
EXPECTED TO BE JUST BELOW WIND ADVISORY CRITERIA ON THE OBX BUT WE
WILL CONTINUE TO MONITOR THE SITUATION. SEE MARINE DISCUSSION BELOW
FOR MORE INFO.
REALLY NOT MUCH CHANGE TO THE PUBLIC GRIDS DURING THE SHORT TERM
WITH DRY FORECAST THROUGH FRI EVENING ASSOCIATED WITH DEEP HIGH
PRESSURE AFFECTING THE AREA. NWP GUIDANCE IN FAIR AGREEMENT THAT
FRONT OFFSHORE WILL CREEP BACK TOWARDS THE COAST AS WE MOVE INTO AND
THROUGH THE WEEKEND. ADDITIONALLY...FLOW ALOFT WILL GRADUALLY BECOME
SW OVER THE WEEKEND BETWEEN RIDGING OFFSHORE AND TROUGHING TO OUR W
ALLOWING DEEPER MOISTURE FROM THE GULF TO SLOWLY INCREASE. FOR THESE
REASONS WILL KEEP A SLIGHT CHANCE OF SHOWERS MAINLY FOR COASTAL
ZONES FRI NITE THROUGH SUN EXCEPT CHANCE NEAR THE CENTRAL OUTER
BANKS CLOSEST TO SFC SUPPORT AND DEEPEST MOISTURE.
ANOTHER ISSUE WILL BE THE EXTENT OF LOW CLOUDS TO AFFECT THE AREA IN
THE SHORT TERM WITH LOW LVL NE FLOW PUMPING IN ATLC MOISTURE. AT
THIS POINT THINK FRI NITE WILL SEE MORE EXTENSIVE STRATUS ESP NEAR
COAST AS FRESH NE FLOW TRAPS MOISTURE UNDER AN EVEN STRONGER
INVERSION...AS SHORT WAVE MID LVL RIDGING BUILDS OVER THE EC.
PERIODS OF LOWER CLOUDS TO CONTINUE AFFECTING ESP ERN HALF THROUGH
SUN.
TEMPS EXPECTED TO BE SLIGHTLY COOLER TOMORROW WITH 850MB CAA ESP
EARLY IN THE DAY...IN THE M-U70S AREA WIDE AND REALLY NOT CHANGING
MUCH IN THE OBX WITH STIFF NE WINDS. TEMPS A COUPLE DEGREES WARMER
AS WE MOVE THROUGH THE WEEKEND WITH 850 TEMPS COMING UP A TOUCH.
LOWS EXPECTED TO RANGE FROM THE U50S INLAND TO U60S/NR 70 OBX
THROUGH THE PERIOD.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
LITTLE CHANGE TO THE EXTENDED FORECAST WITH SFC HIGH PRES RIDGE
EXTENDING OVER THE AREA FROM THE NE. THIS WILL RESULT IN CONTINUED
NE FLOW OVER THE AREA...WITH TEMPS GENERALLY HIGHS IN UPPER 70S/80.
WILL STILL CONTINUE SLIGHT CHANCE FOR POPS ALONG THE COAST FOR MUCH
OF THE PERIOD WITH TROUGH LINGERING. BOTH GFS/ECMWF/HPC SHOW LOW
PRESSURE DEVELOPING OFF THE COAST MID/LATE NEXT WEEK...SO WILL NEED
TO KEEP AN EYE ON THAT AS WE GET INTO NEXT WEEK.
&&
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
CLEAR SKIES OVERNIGHT WITH A LIGHT NORTHEAST SURFACE WIND. FORECAST
SOUNDINGS SHOW DRY LOW LEVELS SO NOT EXPECTING ANY FOG. EXPECTING A
SCT-BKN STRATOCU DECK TO COME IN AROUND 12-13Z AND LINGER THROUGH
THE DAY. NORTHEAST WINDS WILL INCREASE AS PRESSURE GRADIENT TIGHTENS
IN BETWEEN HIGH PRESSURE BUILDING INTO NEW ENGLAND AND A STATIONARY
FRONT OFF THE SOUTHEAST COAST. SPEEDS WILL INCREASE TO AROUND 15
KNOTS SUSTAINED WITH GUSTS IN THE MID 20S FROM LATE MORNING ON.
AS CSTL TRF BECOMES MORE DEFINED FRI NIGHT INTO SAT HAVE BETTER CHC
OF SOME LOWER CIGS WITH MVFR CONDITIONS DEVELOPING. LATER SUN
THROUGH EARLY NEXT WEEK ANOTHER STRONG HIGH BUILDS TO THE N WITH
MAINLY VFR EXPECTED.
&&
.MARINE...
BREEZY CONDITIONS ALONG THE COAST THIS EVENING IN BETWEEN HIGH
PRESSURE BUILDING INTO NEW ENGLAND AND THE STATIONARY FRONT
LINGERING OFF THE SOUTHEAST COAST. WINDS WILL INCREASE OVERNIGHT
INTO THURSDAY AS HIGH STRENGTHENS AND GRADIENT TIGHTENS. FORECAST IS
IN VERY GOOD SHAPE ACCORDING TO COASTAL/BUOY OBSERVATIONS. NO
CHANGES NEEDED.
.RIP CURRENTS...STRONG WINDS AND BUILDING SEAS WILL LEAD TO HIGH
RIP THREAT FRI FOR ALL EAST FACING BEACHES FROM LOOKOUT N.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...HIGH SURF ADVISORY FROM 8 AM FRIDAY TO 8 AM EDT SATURDAY FOR
NCZ103.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT SATURDAY FOR AMZ135.
SMALL CRAFT ADVISORY UNTIL 5 AM EDT SATURDAY FOR AMZ130.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR AMZ150-152-154.
SMALL CRAFT ADVISORY UNTIL 5 AM EDT SUNDAY FOR AMZ156.
SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 5 AM EDT SUNDAY
FOR AMZ158.
&&
$$
SYNOPSIS...MW
NEAR TERM...JBM
SHORT TERM...MW
LONG TERM...CQD
AVIATION...HSA
MARINE...HSA
000
FXUS62 KRAH 190113
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
913 PM EDT THU SEP 18 2008
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL EXTEND INTO THE AREA THROUGH THE
WEEKEND...BRINGING COOL AND DRY CONDITIONS TO CENTRAL NORTH CAROLINA.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 215 PM THURSDAY...
SURFACE HIGH PRESSURE WILL CONTINUE TO NOSE SOUTHWARD THROUGH NC
AS ITS CENTER SHIFTS FROM SOUTHEAST ONTARIO EASTWARD TO OFF THE NOVA
SCOTIA COAST BY THE END OF FRIDAY. WITH ANTICYCLONIC FLOW UP THROUGH
THE MID LEVELS AND A GENERALLY DRY AND SUBSIDING COLUMN... THE QUIET
WEATHER WILL PERSIST THROUGH TOMORROW... ALBEIT WITH A COUPLE OF
CAVEATS.
FOR TONIGHT: THE FLAT RAGGED DAYTIME CLOUDS OVER THE SOUTHERN CWA...
WHERE THE SLIGHTLY HIGHER UPPER 50S/LOWER 60S SURFACE DEW POINTS
PERSIST... WILL SOON DISSIPATE... LEAVING CLEAR SKIES. BUT
TRAJECTORIES SUGGEST THAT AN AREA OF LOW LEVEL MOISTURE NOW NOTED
ACROSS NJ/PA WILL ADVECT SSW TOWARD NC LATE TONIGHT INTO FRIDAY
MORNING... AND MODEL PROJECTIONS ON THE 295K SURFACE SUPPORT THIS.
FORECAST SKY COVER REFLECTS AN INCREASE TO PARTLY CLOUDY SKIES FROM
NORTHEAST TO SOUTHWEST LATE TONIGHT THROUGH FRIDAY MORNING. THIS
MOISTURE DOESN`T APPEAR TO BE TERRIBLY DEEP OR EXPANSIVE HOWEVER...
AND THE MODELS AGREE ON WEAK DOWNGLIDE AT THIS LEVEL... SO IT SHOULD
BE MAINLY SCATTERED IN COVERAGE. CURRENT LOWS FROM 55-60 STILL LOOK
REASONABLE GIVEN THE AFTERNOON DROP IN DEW POINTS... THE LATE
ARRIVAL OF THE CLOUDS... AND THE LIGHT BREEZE FROM THE NORTHEAST.
FOR FRIDAY... THE PRESSURE GRADIENT WILL CONTINUE TO TIGHTEN AS THE
SURFACE HIGH MOVES EAST WITH THE BAROCLINIC ZONE STILL SITTING OFF
THE COAST. AS THE LOW LEVEL INVERSION MIXES OUT IN THE MORNING... WE
SHOULD SEE PREVAILING NORTHEAST WINDS QUICKLY JUMP UP TO 10-20 MPH
WITH SOME GUSTS TO 25 MPH. OTHERWISE... THE AFOREMENTIONED BATCH OF
CLOUDS SHOULD CONTINUE MOVING SOUTHWEST TO THE SOUTHERN CWA FRIDAY
MORNING... LEAVING MOSTLY SUNNY SKIES... ALTHOUGH A FEW FLAT
CONVECTIVE CUMULUS MAY POP UP THROUGH THE AFTERNOON. WITH
THICKNESSES EXPECTED TO BE ONLY MARGINALLY LOWER THAN TODAY...
TEMPERATURES SHOULD FOLLOW SUIT... WITH HIGHS IN THE IN THE 76-81
RANGE. -GIH
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 245 PM THURSDAY...
FRIDAY NIGHT THROUGH SATURDAY...DRY AIR SURFACE RIDGE WILL STRETCH
FROM THE SOUTHERN NEW ENGLAND COAST TO THE WESTERN CAROLINAS.
MEANWHILE AN AREA OF LOW PRESSURE WILL MEANDER OFF CAPE FEAR. THE
DIFFERENCE IN PRESSURE BETWEEN THE RIDGE AND THE LOW OFFSHORE WILL
CREATE A STEADY NE FLOW OVER THE AREA WITH THE STEADY/BREEZY WINDS
EXPECTED EAST OF HIGHWAY 1. THIS CIRCULATION PATTERN WILL ADVECT
POCKETS OF MOISTURE IN THE LOWEST 10000FT FEET. THIS WILL RESULT IN
PERIODS OF CLOUDINESS...AGAIN MAINLY EAST OF HIGHWAY 1. MECHANISMS
FOR LIFT TO GENERATE PRECIPITATION ARE ABSENT SO DO NOT EXPECT ANY PRECIPITATION
THROUGH THE PERIOD.
THE LOW LEVEL NE FLOW WILL RESULT IN MAX TEMPS SLIGHTLY
COOLER THAN NORMAL. THICKNESSES WITH FULL TO PARTIAL SUN SUPPORT MAX
TEMPS MAINLY IN THE MID 70S. A STEADY NE WIND FRIDAY NIGHT WILL KEEP
THE BOUNDARY LAYER WELL MIXED. THIS SHOULD RESULT IN TEMPS A COUPLE
OF DEGREES WARMER THAN NORMALLY OCCUR WHEN THE WINDS DECOUPLE AT THE
SURFACE. USED A BLAND OF MOS TEMP GUIDANCE FOR MIN TEMP FORECAST FRI
NIGHT/SATURDAY MORNING.
SATURDAY NIGHT THROUGH SUNDAY NIGHT...NOT MUCH CHANGE IN THE
SENSIBLE WEATHER THROUGH THIS PERIOD. SURFACE RIDGE AXIS WILL
CONTINUE OVER THE WESTERN CAROLINAS WHILE SURFACE LOW OFFSHORE OF
CAPE FEAR IS FORECAST TO WEAKEN/DISSIPATE. RELAXING OF PRESSURE GRADIENT
WILL LEAD TO A WEAKER WIND FIELD. THE WEAKER NORTHEAST FETCH WILL
RESULT IN LESS CLOUDINESS BELOW 10000 FEET. HOWEVER...MAY SEE SOME
ENHANCEMENT OF HIGH LEVEL CLOUDINESS AS FLOW ALOFT BACKS AND
STRENGTHENS IN RESPONSE TO A MINOR SHORT WAVE THAT SHEARS
NORTHEAST ACROSS THE OHIO VALLEY. THUS EXPECT A CONTINUATION OF
PARTLY CLOUDY SKIES.
THICKNESSES SUNDAY REBOUND 10 TO 13 METERS FROM SATURDAY THICKNESSES.
THE MODERATING AIR MASS COUPLED WITH A WEAKER NE SURFACE FLOW
SHOULD TRANSLATES TO MAX TEMPERATURES 3 TO 5 DEGREES WARMER SUNDAY
COMPARED TO SATURDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 245 PM THURSDAY...
MONDAY THROUGH WEDNESDAY...UPPER LEVEL RIDGE WILL BUILD FROM TX
INTO THE GREAT LAKES/SOUTHERN ONTARIO THROUGH THIS PERIOD WITH
BAGGY UPPER LEVEL TROUGH OFF THE NEW ENGLAND COAST EXTENDING SOUTH
SOUTHWEST TO THE VICINITY OF THE SOUTHEAST UNITED STATES THE
BUILDING UPPER LEVEL RIDGE TO OUR WEST SHOULD STRENGTHEN A NORTH-
SOUTH SURFACE RIDGE FROM QUEBEC SOUTHWARD ALONG THE EASTERN
SEABOARD. THIS WEATHER PATTERN USUALLY SIGNALS A DRY AND SLIGHTLY
COOLER THAN NORMAL CONDITIONS FOR CENTRAL NORTH CAROLINA.
FOR WEDNESDAY THROUGH THURSDAY...MEDIUM RANGE GUIDANCE IN
REASONABLY GOOD AGREEMENT DEPICTING THE UPPER LEVEL RIDGE CLOSING
OFF AND DRIFTING SLOWLY EAST ACROSS NEW ENGLAND. THIS IS TURN
DEVELOPS A WEAK CLOSED UPPER LEVEL LOW OVER THE SOUTHEAST UNITED
STATES WHICH INDUCES SURFACE CYCLOGENESIS OFF THE GA/SC COAST.
WHILE NOT OUT OF THE REALM OF POSSIBILITIES...THIS TYPE OF PATTERN
IS A BIT ANOMALOUS TO THIS TIME OF YEAR AND THE UPPER LEVEL LOW IS
RATHER WEAK. WHILE BAROCLINICITY MAY INCREASE OFFSHORE WITH THE
COOLER AIR ASSOCIATED WITH THE BUILDING RIDGE CROSSING THE WARM
WATERS LEADING TO SOME CYCLOGENESIS...MODELS MAY BE UNDERPLAYING
THE DRY AIR AND SUBSIDENCE ASSOCIATED WITH THE SURFACE RIDGE OVER
CENTRAL NORTH CAROLINA. THUS...PREFER TO KEEP WEDNESDAY INTO
THURSDAY DRY WITH TEMPERATURES REMAINING SLIGHTLY BELOW NORMAL.
THE CONTRAST BETWEEN THE SURFACE RIDGE AND THE CONDITIONS OFFSHORE
MAY LEAD TO ENHANCE LOW LEVEL NORTHEAST FLOW OVER THE EASTERN
COUNTIES. FOR NOW...WILL MAINTAIN NEAR SURFACE WINDS THU AROUND
15 KNOTS.
&&
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
AS OF 905 PM...
WIND SPEEDS ABOVE THE BOUNDARY LAYER ARE BEGINNING TO INCREASE AS
THIS AIR LOSES THE INFLUENCE OF FRICTION WITH THE SURFACE. THE
PRESSURE GRADIENT IS TIGHTEST TO THE EAST AND THE FORECAST OF LOW
LEVEL WIND SHEAR IN THE EAST TOWARD MORNING IS RETAINED.
CLOUDS IN VIRGINIA HAVE LARGELY DISSIPATED. THE MOISTURE
ASSOCIATED WITH THESE CLOUDS WILL ADVANCE INTO NORTH CAROLINA ON
NORTHEAST FLOW TONIGHT AND ADVECT WEST TOWARD THE MOUNTAINS DURING
THE MORNING. EXPECT MOSTLY SCATTERED CLOUDS...BUT SOME LOW VFR
CEILINGS ARE POSSIBLE DURING THE MORNING HOURS.
A LOW PRESSURE CENTER OFF THE CAROLINA COAST WILL DRIFT WEST AND
CONTINUE TO KEEP A SIGNIFICANT PRESSURE GRADIENT OVER NORTH
CAROLINA. LOW LEVEL WIND SHEAR IS LIKELY TO BE A THREAT AGAIN
FRIDAY NIGHT.
ANOTHER PERIOD OF CLOUDINESS MAY OCCUR SATURDAY AND SATURDAY NIGHT
AS MOISTURE POOLS ALONG A TROUGH POSITIONED ALONG THE COAST.
A SECOND PERIOD OF LOW STRATUS IS EXPECTED MONDAY NIGHT. OTHERWISE
VFR CONDITIONS EXPECTED.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
000
FXUS62 KILM 182314
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
710 PM EDT THU SEP 18 2008
.SYNOPSIS...
HIGH PRESSURE ACROSS THE NORTHEAST WILL RIDGE INTO THE CAROLINAS
INTO THE WEEKEND AND BRING COOLER THAN NORMAL TEMPERATURES TO THE
REGION. A TROUGH OF LOW PRESSURE WILL DEVELOP OFFSHORE AND MOVE
CLOSE ENOUGH TO THE AREA TO INCREASE THE CHANCE OF SHOWERS LATE IN
THE WEEKEND AND INTO EARLY NEXT WEEK...MAINLY ALONG THE COASTAL
COUNTIES. TEMPERATURES WILL REMAIN SLIGHTLY BELOW NORMAL THROUGH
THE PERIOD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM THURSDAY...SFC CHARTS VERY SIMILAR TO LAST NIGHT WITH
HIGH PRESSURE CENTERED NORTH OF NY STATE RESULTING IN A N TO NE
WIND LOCALLY. IN CONTRAST TO LAST NIGHT...THE FLOW IN THE MID LEVELS
IS A DRY N TO NWRLY DIRECTION IN THE WAKE OF MID LVL TROUGH. OTHER
THAN SOME MINIMAL COVERAGE OF FLAT CU INLAND NEXT FEW HOURS EXPECT
CLEAR SKIES. TEMPS SIMILAR TO LAST NIGHT WITH LOWS IN THE LOW 60S
COAST TO MID/UPPER 50S INLAND (SEE HYDILM FOR MORNING LOWS).
SHOULD WINDS BE JUST A BIT LIGHTER THAN FCST THEN INLAND LOCATIONS
MAY RADIATE BETTER AND BE UP TO A CATEGORY COOLER. THE COAST HAS A
MUCH BETTER CHANCE OF STAYING MIXED ENOUGH FOR THIS TO NOT HAPPEN.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...NOT MUCH CHANGE FROM THE PREVIOUS FORECAST
WITH HIGH ENTRENCHED ACROSS THE NORTHEAST AND RIDGING INTO THE
CAROLINAS WE CAN EXPECT A SUNNY DAY ACROSS THE REGION ON FRIDAY
WITH AN INCREASE IN CLOUDS ON SATURDAY ESPECIALLY ALONG THE
COASTAL COUNTIES AS TROUGH OFFSHORE MOVES TO THE WEST AND MODELS
STILL SHOWING INCREASE IN RH VALUES. HAVE KEPT THE PREVIOUS
MENTIONED SHOWERS ALONG THE COASTAL COUNTIES AND SLIGHT CHANCE
ACROSS THE ADJACENT INLAND COUNTIES. TEMPS TO RUN SLIGHTLY BELOW
NORMAL FOR THE NEXT FEW DAYS AS NE WIND FLOW ACROSS THE REGION
KEEPS US COOLER THAN NORMAL.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...A 500 MB SPLIT FLOW ACROSS THE EASTERN HALF
OF THE U.S. WILL BRING THE POSSIBILITY OF AN EXTENDED PERIOD OF
UNSETTLED WEATHER TO THE CAROLINAS. UPPER LEVEL RIDGING ACROSS THE
OHIO VALLEY ON SUNDAY WILL AMPLIFY INTO A CLOSED HIGH OVER THE GREAT
LAKES TUESDAY INTO WEDNESDAY. BOTH THE ECMWF AND THE GFS NOW
INDICATE VORTICITY SOUTH OF THE UPPER RIDGE WILL CONSOLIDATE INTO AN
UPPER LOW OVER THE CAROLINAS WEDNESDAY INTO THURSDAY. THIS LOOKS
LIKE A REX BLOCK ON 500 MB PROGS...BUT SHOULD BE TOO PROGRESSIVE A
PATTERN TO TECHNICALLY CALL A BLOCK.
AT THE SURFACE A STALLED FRONT JUST OFFSHORE WILL DO LITTLE SUNDAY
THROUGH TUESDAY. COOL AND DRY NORTHEAST LOW-LEVEL FLOW ON THE INLAND
SIDE OF THIS BOUNDARY WILL KEEP TEMPERATURES A FEW DEGREES BELOW
NORMAL. ONCE THE UPPER LOW FORMS ON WEDNESDAY...SURFACE LOW PRESSURE
WILL BEGIN TO DEVELOP ALONG THE FRONT OFFSHORE. A STRENGTHENING
EASTERLY (ONSHORE) FLOW AROUND THE UPPER LOW SHOULD ADVECT DEEP
LAYER MOISTURE BACK INTO THE AREA LATE WEDNESDAY INTO THURSDAY.
AN INTERESTING ASPECT TO CONSIDER WITH THIS SCENARIO IS HOW MANY
TROPICAL CHARACTERISTICS A SLOW-MOVING FRONTAL LOW COULD PICK UP
WHILE OVER THE GULF STREAM FOR SEVERAL DAYS. THE HPC EXTENDED
DISCUSSION GIVES MORE DETAILS ABOUT POSSIBLE IMPACTS SHOULD AN
SUBTROPICAL TRANSITION OCCUR. MORE MUNDANE TO CONSIDER...BUT
SITUATIONS SUCH AS THESE OFTEN WRAP CONSIDERABLE DRY AIR IN FROM THE
NORTH WHICH LIMITS THE WEST AND NORTHWESTWARD PENETRATION OF RAIN.
THE UPPER LOW INLAND MAY MITIGATE THIS SOME...BUT MANY POSSIBILITIES
REMAIN OPEN. SINCE THIS IS STILL A 6 AND 7 DAY FORECAST WE HAVE ONLY
RAISED POPS 10-20% ABOVE CLIMATOLOGY UNTIL DETAILS CAN GET HAMMERED
OUT OVER THE NEXT FEW DAYS.
&&
.AVIATION /00Z THURSDAY THROUGH TUESDAY/...
VFR CONDITIONS THROUGH THE FORECAST PERIOD. TIGHT GRADIENT SETS UP FOR
FRIDAY. BUMPED THE WINDS UP A BIT AS BUFKIT SHOWS STRONG WINDS AT
THE BOUNDARY LAYER...WITH THINGS MIXING PRETTY GOOD A COUPLE OF
HOURS AFTER DAYBREAK. WINDS WILL DIMINISH SOMEWHAT TOWARD THE END OF
THE 24 HOUR FORECAST PERIOD.
OUTLOOK THROUGH MONDAY...QUITE A BIT OF UNCERTAINTY SATURDAY THROUGH
TUESDAY. CONTINUED NORTHEAST FLOW...WITH LOW PRESSURE POSSIBLY
SETTING UP CLOSE ENOUGH TO SHORE TO AFFECT COASTAL TERMINALS WITH
LOWER CEILINGS AND RAIN SATURDAY/SUNDAY. IF THE LOW SETS UP FURTHER
OFFSHORE...LOOK FOR VFR CONDITIONS...HOWEVER WINDY CONDITIONS ARE
EXPECTED SATURDAY...MONDAY AND TUESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM THURSDAY...NORTHEASTERLY FLOW IN A MODERATELY STRONG
GRADIENT WILL CONTINUE. AS WITH PAST FEW NIGHTS SPEEDS MAY
INCREASE LATE AS A LL COASTAL JET FORMS. THE SPEED INCREASE WILL
ALSO BE SYNOPTICALLY FORCED AS LOW PRESSURE BEGINS TO DEVELOP ON
THE FRONT WELL OFFSHORE. NORTHERN ZONES MAY START TO SEE SCA
CONDITIONS BY THE END OF THE PD...WHICH IS BASICALLY WHEN THE
ADVISORY STARTS ANYWAY.
&&
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...WILL KEEP THE MENTION OF SCA FOR FRIDAY AS
NE FLOW INCREASES ACROSS THE OFFSHORE WATERS AND SEAS KICK UP TO
6-8 FEET WITH NEARSHORE SEAS RUNNING 2-5. WINDS WILL RUN BETWEEN
20 TO 25 KTS WITH GUSTS TO 30 KTS. CONDITIONS WILL START TO
IMPROVE BY SATURDAY AFTERNOON WITH WINDS ABATING A BIT AND SEAS
WILL COME DOWN AS WELL. WITH OFFSHORE TROUGH MOVING TO THE WEST ON
SATURDAY WILL KEEP THE MENTION OF CHANCE OF SHOWERS BASICALLY
THROUGH THE PERIOD.
&&
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 PM THURSDAY...AS OF 3 PM WEDNESDAY...A STALLED FRONT WILL
REMAIN OFFSHORE SUNDAY THROUGH MONDAY. A LARGE AND UNSEASONABLY
STRONG HIGH PRESSURE OVER NEW ENGLAND WILL SLOWLY RIDGE SOUTH AND
PRODUCE A PERIOD OF MODERATE NORTHEASTERLY WINDS ACROSS THE
WATERS. WINDS ON SUNDAY 10-15 KT WILL INCREASE CLOSER TO 20 KT BY
MONDAY NIGHT AS THE GRADIENT TIGHTENS FURTHER.
BEYOND THE SCOPE OF OUR 5-DAY FORECAST BUT STILL WORTH A MENTION...
MODELS ARE BECOMING MORE INSISTENT THAT A NOR`EASTER OR PERHAPS A
HYBRID/SUBTROPICAL SYSTEM MAY DEVELOP ALONG THE CAROLINA COAST NEXT
WEDNESDAY OR THURSDAY. THIS IS STILL 6 AND 7 DAYS OUT BUT IS WORTHY
OF CONSIDERATION FOR PLANNING PURPOSES GIVEN THE POTENTIAL IMPACT ON
THE MARINE COMMUNITY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT FRIDAY FOR AMZ250-
252-254-256.
&&
$$
SYNOPSIS...01
NEAR TERM...MBB
SHORT TERM...01
LONG TERM...TRA
AVIATION...43
000
FXUS62 KMHX 181943
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
343 PM EDT THU SEP 18 2008
.SYNOPSIS...
STRONG HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE NE STATES
THROUGH FRIDAY AND MOVE E THROUGH SATURDAY...AS A SLOW MOVING
FRONTAL SYSTEM REMAINS OFFSHORE. AN EVEN STRONGER AREA OF HIGH
PRESSURE IS EXPECTED TO BUILD INTO THE AREA EARLY TO MID NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
SHOULD BE A QUIET...FALL LIKE NIGHT AS A REINFORCING 1030MB + HIGH
PRES AREA BUILDS INTO THE AREA FROM THE NE STATES...AND AN UPPER
TROUGH GRADUALLY SHIFTS OFFSHORE. THIS WILL ALLOW DEEP DRY AIR TO
CONTINUE MOVING OVER THE AREA WHICH WILL ESSENTIALLY GIVE MOST OF
THE AREA ALMOST NO CHANCE OF PRECIP. THE STRONG HIGH PRES BUILDING
INTO THE AREA WILL ALLOW NE WINDS TO CONTINUE OVERNIGHT...AND THUS
THE BETTER MIXED ATMOSPHERE WILL PREVENT TEMPS FROM GETTING QUITE
AS COOL AS THIS MORNINGS MID 50S INLAND AND SHOULD ALSO PREVENT
FOG FORMATION. HOWEVER...850MB CAA WILL BEGIN AGAIN AND SHOULD
STILL ALLOW TEMPS TO DROP INTO THE U50S INLAND WITH 60S NEAR THE
COAST. SOME POTENTIAL FOR STRATUS LATE TONIGHT ESP NR COAST AS WINDS GO
MORE NE AND INCREASE...TRAPPING MOISTURE UNDER DEVELOPING
INVERSION. GIVEN VERY DRY CONDITIONS OVER THE AREA AND UPSTREAM
THINK MODELS MAY BE A LITTLE OVERDONE BUT ENOUGH SUPPORT TO SAY AT
LEAST PARTLY CLOUDY LATE.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
MAIN STORY THIS FORECAST PERIOD WILL BE COASTAL IMPACTS FROM THE
LONG FETCH OF STRONG NE/ENE WINDS SETTING UP OFF THE EAST
COAST...ASSOCIATED WITH THE INTERACTION BETWEEN HIGH PRESSURE MOVING
E FROM NEW ENGLAND AND THE WAVY FRONTAL SYSTEM OFFSHORE. WE ARE
EXPECTING SOME MINOR OCEAN OVERWASH AND BEACH EROSION FROM THIS
PATTERN AT NORMAL PRONE AREAS IN THE OUTER BANKS (PORTIONS OF HWY 12
NEAR KITTY HAWK/PEA ISLAND/RODANTHE)...IN ADDITION TO A VERY HIGH
RISK OF RIP CURRENTS AND DANGEROUS SURF CONDITIONS. THESE IMPACTS
WILL BY FAR BE FELT THE MOST AT EAST FACING BEACHES ALONG THE OUTER
BANKS AND A MUCH LESSER EXTENT AT SOUTH FACING BEACHES DUE TO THE
PREVAILING NE WIND AND WAVE DIRECTION. AT THIS POINT WINDS ARE
EXPECTED TO BE JUST BELOW WIND ADVISORY CRITERIA ON THE OBX BUT WE
WILL CONTINUE TO MONITOR THE SITUATION. SEE MARINE DISCUSSION BELOW
FOR MORE INFO.
REALLY NOT MUCH CHANGE TO THE PUBLIC GRIDS DURING THE SHORT TERM
WITH DRY FORECAST THROUGH FRI EVENING ASSOCIATED WITH DEEP HIGH
PRESSURE AFFECTING THE AREA. NWP GUIDANCE IN FAIR AGREEMENT THAT
FRONT OFFSHORE WILL CREEP BACK TOWARDS THE COAST AS WE MOVE INTO AND
THROUGH THE WEEKEND. ADDITIONALLY...FLOW ALOFT WILL GRADUALLY BECOME SW
OVER THE WEEKEND BETWEEN RIDGING OFFSHORE AND TROUGHING TO OUR W
ALLOWING DEEPER MOISTURE FROM THE GULF TO SLOWLY INCREASE. FOR THESE
REASONS WILL KEEP A SLIGHT CHANCE OF SHOWERS MAINLY FOR COASTAL
ZONES FRI NITE THROUGH SUN EXCEPT CHANCE NEAR THE CENTRAL OUTER
BANKS CLOSEST TO SFC SUPPORT AND DEEPEST MOISTURE.
ANOTHER ISSUE WILL BE THE EXTENT OF LOW CLOUDS TO AFFECT THE AREA IN
THE SHORT TERM WITH LOW LVL NE FLOW PUMPING IN ATLC MOISTURE. AT
THIS POINT THINK FRI NITE WILL SEE MORE EXTENSIVE STRATUS ESP NEAR COAST
AS FRESH NE FLOW TRAPS MOISTURE UNDER AN EVEN STRONGER
INVERSION...AS SHORT WAVE MID LVL RIDGING BUILDS OVER THE EC.
PERIODS OF LOWER CLOUDS TO CONTINUE AFFECTING ESP ERN HALF THROUGH
SUN.
TEMPS EXPECTED TO BE SLIGHTLY COOLER TOMORROW WITH 850MB CAA ESP
EARLY IN THE DAY...IN THE M-U70S AREA WIDE AND REALLY NOT CHANGING
MUCH IN THE OBX WITH STIFF NE WINDS. TEMPS A COUPLE DEGREES WARMER
AS WE MOVE THROUGH THE WEEKEND WITH 850 TEMPS COMING UP A TOUCH.
LOWS EXPECTED TO RANGE FROM THE U50S INLAND TO U60S/NR 70 OBX
THROUGH THE PERIOD.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
LITTLE CHANGE TO THE EXTENDED FORECAST WITH SFC HIGH PRES RIDGE
EXTENDING OVER THE AREA FROM THE NE. THIS WILL RESULT IN CONTINUED
NE FLOW OVER THE AREA...WITH TEMPS GENERALLY HIGHS IN UPPER 70S/80.
WILL STILL CONTINUE SLIGHT CHANCE FOR POPS ALONG THE COAST FOR MUCH
OF THE PERIOD WITH TROUGH LINGERING. BOTH GFS/ECMWF/HPC SHOW LOW
PRESSURE DEVELOPING OFF THE COAST MID/LATE NEXT WEEK...SO WILL NEED
TO KEEP AN EYE ON THAT AS WE GET INTO NEXT WEEK.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
EXPECT CONT PRIMARILY VFR OVERNIGHT. AS STRONG HIGH BUILDS TO THE
N SHLD PRODUCE ENOUGH OF A GRDNT FOR AT LEAST A LIGHT BRZ INLAND
WHICH WOULD LIMIT FOG POTENTIAL. AS LOW LVL FLOW BECOMES MORE NE
LATER TONIGHT AND ESPECIALLY FRI WILL LIKELY SEE MORE LOW LVL
MOISTURE SPREAD ONSHORE...AT THIS TIME APPEARS IF CIGS DO DEVELOP
WOULD BE MAINLY IN VFR RANGE WITH BEST CHC CLOSER TO THE CST. AS
CSTL TRF BECOMES MORE DEFINED FRI NIGHT INTO SAT HAVE BETTER CHC
OF SOME LOWER CIGS WITH MVFR CONDITIONS DEVELOPING. LATER SUN
THROUGH EARLY NEXT WEEK ANOTHER STRONG HIGH BUILDS TO THE N WITH
MAINLY VFR EXPECTED.
&&
.MARINE...
ACTIVE MARINE PD WITH TWO FAIRLY SIGNIFICANT EVENTS. FIRST EVENT
WILL DEVELOP TONIGHT AND CONT INTO SAT AS STRONG HIGH BUILDS TO
THE N WITH WEAK LOW TO THE SE. THIS WILL TIGHTEN UP GRDNT WITH
N/NE INCREASING TO SOLID SCA OVERNIGHT WITH NEAR GALE CONDITIONS
EXPECTED ON FRI. THE STRONG WINDS WILL LEAD TO BUILDING SEAS WITH
8 TO 11 FEET EXPECTED CNTRL AND NRN WTRS FRI WITH 5 TO 8 FT S. THE
COMBO OF STRONG ONSHORE WINDS...HIGH ASTRO TIDES AND BUILDING SEAS
WILL LEAD TO HIGH SURF ADVRY CONDITIONS FROM HATTERAS NORTH
STARTING 12Z FRI THROUGH SAT MORN. HIGH WILL GRAD WEAKEN OVER THE
WEEKEND AND WILL SEE WINDS SLOWLY DIMINISH. DESPITE LOWERING WINDS
LONG NE FETCH WILL KEEP SEAS AOA SCA LVLS FROM OCRACOKE N.
STARTING EARLY NEXT WEEK ANOTHER STRONG HIGH WILL BE BUILDING TO
THE N WITH MDLS SHOWING LOW PRES DEVELOPING TO THE S BY MIDWEEK.
THIS WILL AGAIN LEAD TO INCREASING N/NE WINDS MON INTO TUE. AT
THIS TIME LOOKS LIKE STRONGEST WINDS WILL BE MAINLY BEYOND THIS
FCST PD AS LOW PRES IS EXPECTED TO LIFT N TOWARD NC WED/THU TIME
FRAME. IF LOW DOES DEVELOP WILL HAVE POTENTIAL FOR AT LEAST GALES
MID PART OF NEXT WEEK WITH THREAT OF OVERWASH...BUT HAVE PLENTY OF
TIME TO WATCH THIS EVOLVE.
.RIP CURRENTS...STRONG WINDS AND BUILDING SEAS WILL LEAD TO HIGH
RIP THREAT FRI FOR ALL EAST FACING BEACHES FROM LOOKOUT N.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...HIGH SURF ADVISORY FROM 8 AM FRIDAY TO 8 AM EDT SATURDAY FOR
NCZ103.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT SATURDAY FOR AMZ135.
SMALL CRAFT ADVISORY UNTIL 5 AM EDT SATURDAY FOR AMZ130.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR AMZ150-152-154.
SMALL CRAFT ADVISORY UNTIL 5 AM EDT SUNDAY FOR AMZ156.
SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 5 AM EDT SUNDAY
FOR AMZ158.
&&
$$
SYNOPSIS...MW
NEAR TERM...MW
SHORT TERM...MW
LONG TERM...CQD
AVIATION...RF
MARINE...RF
000
FXUS62 KRAH 181853
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
253 PM EDT THU SEP 18 2008
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL EXTEND INTO THE AREA FROM THE NORTH
THROUGH THE WEEKEND... BRINGING COOL AND DRY CONDITIONS.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 215 PM THURSDAY...
SURFACE HIGH PRESSURE WILL CONTINUE TO NOSE SOUTHWARD THROUGH NC
AS ITS CENTER SHIFTS FROM SOUTHEAST ONTARIO EASTWARD TO OFF THE NOVA
SCOTIA COAST BY THE END OF FRIDAY. WITH ANTICYCLONIC FLOW UP THROUGH
THE MID LEVELS AND A GENERALLY DRY AND SUBSIDING COLUMN... THE QUIET
WEATHER WILL PERSIST THROUGH TOMORROW... ALBEIT WITH A COUPLE OF
CAVEATS.
FOR TONIGHT: THE FLAT RAGGED DAYTIME CLOUDS OVER THE SOUTHERN CWA...
WHERE THE SLIGHTLY HIGHER UPPER 50S/LOWER 60S SURFACE DEW POINTS
PERSIST... WILL SOON DISSIPATE... LEAVING CLEAR SKIES. BUT
TRAJECTORIES SUGGEST THAT AN AREA OF LOW LEVEL MOISTURE NOW NOTED
ACROSS NJ/PA WILL ADVECT SSW TOWARD NC LATE TONIGHT INTO FRIDAY
MORNING... AND MODEL PROJECTIONS ON THE 295K SURFACE SUPPORT THIS.
FORECAST SKY COVER REFLECTS AN INCREASE TO PARTLY CLOUDY SKIES FROM
NORTHEAST TO SOUTHWEST LATE TONIGHT THROUGH FRIDAY MORNING. THIS
MOISTURE DOESN`T APPEAR TO BE TERRIBLY DEEP OR EXPANSIVE HOWEVER...
AND THE MODELS AGREE ON WEAK DOWNGLIDE AT THIS LEVEL... SO IT SHOULD
BE MAINLY SCATTERED IN COVERAGE. CURRENT LOWS FROM 55-60 STILL LOOK
REASONABLE GIVEN THE AFTERNOON DROP IN DEW POINTS... THE LATE
ARRIVAL OF THE CLOUDS... AND THE LIGHT BREEZE FROM THE NORTHEAST.
FOR FRIDAY... THE PRESSURE GRADIENT WILL CONTINUE TO TIGHTEN AS THE
SURFACE HIGH MOVES EAST WITH THE BAROCLINIC ZONE STILL SITTING OFF
THE COAST. AS THE LOW LEVEL INVERSION MIXES OUT IN THE MORNING... WE
SHOULD SEE PREVAILING NORTHEAST WINDS QUICKLY JUMP UP TO 10-20 MPH
WITH SOME GUSTS TO 25 MPH. OTHERWISE... THE AFOREMENTIONED BATCH OF
CLOUDS SHOULD CONTINUE MOVING SOUTHWEST TO THE SOUTHERN CWA FRIDAY
MORNING... LEAVING MOSTLY SUNNY SKIES... ALTHOUGH A FEW FLAT
CONVECTIVE CUMULUS MAY POP UP THROUGH THE AFTERNOON. WITH
THICKNESSES EXPECTED TO BE ONLY MARGINALLY LOWER THAN TODAY...
TEMPERATURES SHOULD FOLLOW SUIT... WITH HIGHS IN THE IN THE 76-81
RANGE. -GIH
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 245 PM THURSDAY...
FRIDAY NIGHT THROUGH SATURDAY...DRY AIR SURFACE RIDGE WILL STRETCH
FROM THE SOUTHERN NEW ENGLAND COAST TO THE WESTERN CAROLINAS.
MEANWHILE AN AREA OF LOW PRESSURE WILL MEANDER OFF CAPE FEAR. THE
DIFFERENCE IN PRESSURE BETWEEN THE RIDGE AND THE LOW OFFSHORE WILL
CREATE A STEADY NE FLOW OVER THE AREA WITH THE STEADY/BREEZY WINDS
EXPECTED EAST OF HIGHWAY 1. THIS CIRCULATION PATTERN WILL ADVECT
POCKETS OF MOISTURE IN THE LOWEST 10000FT FEET. THIS WILL RESULT IN
PERIODS OF CLOUDINESS...AGAIN MAINLY EAST OF HIGHWAY 1. MECHANISMS
FOR LIFT TO GENERATE PRECIP ARE ABSENT SO DO NOT EXPECT ANY PRECIP
THROUGH THE PERIOD.
THE LOW LEVEL NE FLOW WILL RESULT IN MAX TEMPS SLIGHTLY
COOLER THAN NORMAL. THICKNESSES WITH FULL TO PARTIAL SUN SUPPORT MAX
TEMPS MAINLY IN THE MID 70S. A STEADY NE WIND FRIDAY NIGHT WILL KEEP
THE BOUNDARY LAYER WELL MIXED. THIS SHOULD RESULT IN TEMPS A COUPLE
OF DEGREES WARMER THAN NORMALLY OCCUR WHEN THE WINDS DECOUPLE AT THE
SURFACE. USED A BLAND OF MOS TEMP GUIDANCE FOR MIN TEMP FORECAST FRI
NIGHT/SATURDAY MORNING.
SATURDAY NIGHT THROUGH SUNDAY NIGHT...NOT MUCH CHANGE IN THE
SENSIBLE WEATHER THROUGH THIS PERIOD. SURFACE RIDGE AXIS WILL
CONTINUE OVER THE WESTERN CAROLINAS WHILE SURFACE LOW OFFSHORE OF
CAPE FEAR PROGGED TO WEAKEN/DISSIPATE. RELAXING OF PRESSURE GRADIENT
WILL LEAD TO A WEAKER WIND FIELD. THE WEAKER NE FETCH WILL RESULT IN
LESS CLOUDINESS BELOW 10000FT. HOWEVER...MAY SEE SOME ENHANCEMENT OF
HIGH LEVEL CLOUDINESS AS FLOW ALOFT BACKS AND STRENGTHENS IN
RESPONSE TO A MINOR S/W THAT SHEARS NE ACROSS THE OH VALLEY. THUS
EXPECT A CONTINUATION OF PARTLY CLOUDY SKIES.
THICKNESSES SUNDAY REBOUND 10-13M FROM SATURDAY THICKNESSES. THE
MODERATING AIR MASS COUPLED WITH A WEAKER NE SURFACE FLOW SHOULD
TRANSLATES TO MAX TEMPS 3-5 DEGREES WARMER SUN COMPARED TO SATURDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 245 PM THURSDAY...
MON-WED...UPPER LEVEL RIDGE WILL BUILD FROM TX INTO THE GREAT
LAKES/SOUTHERN ONTARIO THROUGH THIS PERIOD WITH BAGGY UPPER LEVEL
TROUGH OFF THE NEW ENGLAND COAST EXTENDING SSW TO THE VICINITY OF
THE SE U.S. THE BUILDING UPPER LEVEL RIDGE TO OUR WEST SHOULD
STRENGTHEN A NORTH-SOUTH SURFACE RIDGE FROM QUEBEC SOUTHWARD ALONG
THE EASTERN SEABOARD. THIS WEATHER PATTERN USUALLY SIGNALS A DRY AND
SLIGHTLY COOLER THAN NORMAL CONDITIONS FOR CENTRAL NC.
FOR WED-THU...MEDIUM RANGE GUIDANCE IN REASONABLY GOOD AGREEMENT
DEPICTING THE UPPER LEVEL RIDGE CLOSING OFF AND DRIFTING SLOWLY EAST
ACROSS NEW ENGLAND. THIS IS TURN DEVELOPS A WEAK CLOSED UPPER LEVEL
LOW OVER THE SE U.S WHICH INDUCES SURFACE CYCLOGENESIS OFF THE GA/SC
COAST. WHILE NOT OUT OF THE REALM OF POSSIBILITIES...THIS TYPE OF
PATTERN IS A BIT ANOMALOUS TO THIS TIME OF YEAR AND THE UPPER LEVEL
LOW IS RATHER WEAK. WHILE BAROCLINICITY MAY INCREASE OFFSHORE WITH
THE COOLER AIR ASSOCIATED WITH THE BUILDING RIDGE CROSSING THE WARM
WATERS LEADING TO SOME CYCLOGENESIS...MODELS MAY BE UNDERPLAYING THE
DRY AIR AND SUBSIDENCE ASSOCIATED WITH THE SURFACE RIDGE OVER
CENTRAL NC. THUS...PREFER TO KEEP WED INTO THU DRY WITH TEMPS
REMAINING SLIGHTLY BELOW NORMAL. THE CONTRAST BETWEEN THE SURFACE
RIDGE AND THE CONDITIONS OFFSHORE MAY LEAD TO ENHANCE LOW LEVEL NE
FLOW OVER TH EASTERN COUNTIES. FOR NOW...WILL MAINTAIN NEAR SURFACE
WINDS THU AROUND 15KTS.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 215 PM THURSDAY...
WHILE VFR CONDITIONS WILL PREVAIL OVER MUCH OF THE NEXT 24 HOURS...
A PERIOD OF MVFR OR IFR CLOUDS ARE POSSIBLE LATE TONIGHT INTO EARLY
FRIDAY MORNING... AND LOW LEVEL WIND SHEAR WILL BE A THREAT LATE
TONIGHT.
AN AREA OF LOW LEVEL MOISTURE WILL ADVECT TO THE SSW INTO CENTRAL NC
LATE TONIGHT INTO FRIDAY MORNING. THIS MOISTURE WILL NOT BE
PARTICULARLY DEEP OR EXPANSIVE HOWEVER... SO MOSTLY SCATTERED CLOUDS
WITH 1200-2000 FT BASES ARE EXPECTED. BUT THEY MAY BRIEFLY GO BROKEN
BETWEEN 09Z AND 14Z... SO AVIATION INTERESTS SHOULD KEEP A CLOSE EYE
ON THE LATEST CONDITIONS AND TERMINAL FORECASTS. ALSO... AS THE
SURFACE BASED INVERSION FORMS LATE TONIGHT... NORTHEAST WINDS ALOFT
AT 1000-2000 FT AGL WILL INCREASE IN RESPONSE TO THE INCREASING
PRESSURE GRADIENT BETWEEN THE SURFACE HIGH TO THE NORTH AND LOWER
PRESSURES TO THE SOUTHEAST. LOW LEVEL WIND SHEAR IS EXPECTED TO
DEVELOP... MOST PREDOMINANTLY AT FAY/RWI. THIS SHOULD MIX OUT
SHORTLY AFTER DAYBREAK WITH HEATING AND MIXING TAKING PLACE. AFTER
14Z... SCATTERED TO BROKEN CLOUDS WITH BASES AOA 3200 FT ARE
EXPECTED THROUGH EARLY FRIDAY AFTERNOON. -GIH
ANOTHER PERIOD OF CLOUDINESS MAY OCCUR SATURDAY NIGHT INTO SUNDAY AS
MOISTURE POOLS ALONG A TROUGH POSITIONED ALONG THE COAST. THE CLOUDS
WILL BE MOST LIKELY IN THE EAST VERSUS THE WEST. -WSS
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RWH
NEAR TERM...HARTFIELD
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...HARTFIELD/WSS
000
FXUS62 KILM 181850
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
250 PM EDT THU SEP 18 2008
.SYNOPSIS...
HIGH PRESSURE ACROSS THE NORTHEAST WILL RIDGE INTO THE CAROLINAS
INTO THE WEEKEND AND BRING COOLER THAN NORMAL TEMPERATURES TO THE
REGION. A TROUGH OF LOW PRESSURE WILL DEVELOP OFFSHORE AND MOVE
CLOSE ENOUGH TO THE AREA TO INCREASE THE CHANCE OF SHOWERS LATE IN
THE WEEKEND AND INTO EARLY NEXT WEEK...MAINLY ALONG THE COASTAL
COUNTIES. TEMPERATURES WILL REMAIN SLIGHTLY BELOW NORMAL THROUGH
THE PERIOD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM THURSDAY...SFC CHARTS VERY SIMILAR TO LAST NIGHT WITH
HIGH PRESSURE CENTERED NORTH OF NY STATE RESULTING IN A N TO NE
WIND LOCALLY. IN CONTRAST TO LAST NIGHT...THE FLOW IN THE MID LEVELS
IS A DRY N TO NWRLY DIRECTION IN THE WAKE OF MID LVL TROUGH. OTHER
THAN SOME MINIMAL COVERAGE OF FLAT CU INLAND NEXT FEW HOURS EXPECT
CLEAR SKIES. TEMPS SIMILAR TO LAST NIGHT WITH LOWS IN THE LOW 60S
COAST TO MID/UPPER 50S INLAND (SEE HYDILM FOR MORNING LOWS).
SHOULD WINDS BE JUST A BIT LIGHTER THAN FCST THEN INLAND LOCATIONS
MAY RADIATE BETTER AND BE UP TO A CATEGORY COOLER. THE COAST HAS A
MUCH BETTER CHANCE OF STAYING MIXED ENOUGH FOR THIS TO NOT HAPPEN.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...NOT MUCH CHANGE FROM THE PREVIOUS FORECAST
WITH HIGH ENTRENCHED ACROSS THE NORTHEAST AND RIDGING INTO THE
CAROLINAS WE CAN EXPECT A SUNNY DAY ACROSS THE REGION ON FRIDAY
WITH AN INCREASE IN CLOUDS ON SATURDAY ESPECIALLY ALONG THE
COASTAL COUNTIES AS TROUGH OFFSHORE MOVES TO THE WEST AND MODELS
STILL SHOWING INCREASE IN RH VALUES. HAVE KEPT THE PREVIOUS
MENTIONED SHOWERS ALONG THE COASTAL COUNTIES AND SLIGHT CHANCE
ACROSS THE ADJACENT INLAND COUNTIES. TEMPS TO RUN SLIGHTLY BELOW
NORMAL FOR THE NEXT FEW DAYS AS NE WIND FLOW ACROSS THE REGION
KEEPS US COOLER THAN NORMAL.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...A 500 MB SPLIT FLOW ACROSS THE EASTERN HALF
OF THE U.S. WILL BRING THE POSSIBILITY OF AN EXTENDED PERIOD OF
UNSETTLED WEATHER TO THE CAROLINAS. UPPER LEVEL RIDGING ACROSS THE
OHIO VALLEY ON SUNDAY WILL AMPLIFY INTO A CLOSED HIGH OVER THE GREAT
LAKES TUESDAY INTO WEDNESDAY. BOTH THE ECMWF AND THE GFS NOW
INDICATE VORTICITY SOUTH OF THE UPPER RIDGE WILL CONSOLIDATE INTO AN
UPPER LOW OVER THE CAROLINAS WEDNESDAY INTO THURSDAY. THIS LOOKS
LIKE A REX BLOCK ON 500 MB PROGS...BUT SHOULD BE TOO PROGRESSIVE A
PATTERN TO TECHNICALLY CALL A BLOCK.
AT THE SURFACE A STALLED FRONT JUST OFFSHORE WILL DO LITTLE SUNDAY
THROUGH TUESDAY. COOL AND DRY NORTHEAST LOW-LEVEL FLOW ON THE INLAND
SIDE OF THIS BOUNDARY WILL KEEP TEMPERATURES A FEW DEGREES BELOW
NORMAL. ONCE THE UPPER LOW FORMS ON WEDNESDAY...SURFACE LOW PRESSURE
WILL BEGIN TO DEVELOP ALONG THE FRONT OFFSHORE. A STRENGTHENING
EASTERLY (ONSHORE) FLOW AROUND THE UPPER LOW SHOULD ADVECT DEEP
LAYER MOISTURE BACK INTO THE AREA LATE WEDNESDAY INTO THURSDAY.
AN INTERESTING ASPECT TO CONSIDER WITH THIS SCENARIO IS HOW MANY
TROPICAL CHARACTERISTICS A SLOW-MOVING FRONTAL LOW COULD PICK UP
WHILE OVER THE GULF STREAM FOR SEVERAL DAYS. THE HPC EXTENDED
DISCUSSION GIVES MORE DETAILS ABOUT POSSIBLE IMPACTS SHOULD AN
SUBTROPICAL TRANSITION OCCUR. MORE MUNDANE TO CONSIDER...BUT
SITUATIONS SUCH AS THESE OFTEN WRAP CONSIDERABLE DRY AIR IN FROM THE
NORTH WHICH LIMITS THE WEST AND NORTHWESTWARD PENETRATION OF RAIN.
THE UPPER LOW INLAND MAY MITIGATE THIS SOME...BUT MANY POSSIBILITIES
REMAIN OPEN. SINCE THIS IS STILL A 6 AND 7 DAY FORECAST WE HAVE ONLY
RAISED POPS 10-20% ABOVE CLIMATOLOGY UNTIL DETAILS CAN GET HAMMERED
OUT OVER THE NEXT FEW DAYS.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
CLEAR SKY EXPECTED THROUGH THE TAF CYCLE. ONLY CHANGE REQUIRING FM
GROUPS WILL BE TO SHOW DIURNAL TREND IN WINDS...A DROP OFF CLOSE TO
SUNSET AND AN INCREASE AFTER SUNRISE TOMORROW. NORTHEASTERLY
GRADIENT REMAINS MODERATELY STRONG SO GUSTY BREEZE EXPECTED AGAIN
FRIDAY.
OUTLOOK THROUGH MONDAY...VFR GENERALLY EXPECTED. HIGH PRESSURE
BUILDS EAST OF NOVA SCOTIA OVER THE WEEKEND. THE FLOW AROUND THIS
HIGH WILL KEEP A FETCH OF AIR OFF THE OCEAN. THE GFS HINTS AT A
COASTAL TROUGH DEVELOPING WITH SHOWERS ALONG COASTAL AREAS AS EARLY
AS SATURDAY AFTERNOON. IF THIS PANS OUT COASTAL TERMINALS MAY SEE
ISOLATED SHOWERS LATE SATURDAY AND SUNDAY BEFORE A NEW AREA OF HIGH
PRESSURE BUILDS SOUTH OUT OF CANADA BY MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM THURSDAY...NORTHEASTERLY FLOW IN A MODERATELY STRONG
GRADIENT WILL CONTINUE. AS WITH PAST FEW NIGHTS SPEEDS MAY
INCREASE LATE AS A LL COASTAL JET FORMS. THE SPEED INCREASE WILL
ALSO BE SYNOPTICALLY FORCED AS LOW PRESSURE BEGINS TO DEVELOP ON
THE FRONT WELL OFFSHORE. NORTHERN ZONES MAY START TO SEE SCA
CONDITIONS BY THE END OF THE PD...WHICH IS BASICALLY WHEN THE
ADVISORY STARTS ANYWAY.
&&
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...WILL KEEP THE MENTION OF SCA FOR FRIDAY AS
NE FLOW INCREASES ACROSS THE OFFSHORE WATERS AND SEAS KICK UP TO
6-8 FEET WITH NEARSHORE SEAS RUNNING 2-5. WINDS WILL RUN BETWEEN
20 TO 25 KTS WITH GUSTS TO 30 KTS. CONDITIONS WILL START TO
IMPROVE BY SATURDAY AFTERNOON WITH WINDS ABATING A BIT AND SEAS
WILL COME DOWN AS WELL. WITH OFFSHORE TROUGH MOVING TO THE WEST ON
SATURDAY WILL KEEP THE MENTION OF CHANCE OF SHOWERS BASICALLY
THROUGH THE PERIOD.
&&
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 PM THURSDAY...AS OF 3 PM WEDNESDAY...A STALLED FRONT WILL
REMAIN OFFSHORE SUNDAY THROUGH MONDAY. A LARGE AND UNSEASONABLY
STRONG HIGH PRESSURE OVER NEW ENGLAND WILL SLOWLY RIDGE SOUTH AND
PRODUCE A PERIOD OF MODERATE NORTHEASTERLY WINDS ACROSS THE
WATERS. WINDS ON SUNDAY 10-15 KT WILL INCREASE CLOSER TO 20 KT BY
MONDAY NIGHT AS THE GRADIENT TIGHTENS FURTHER.
BEYOND THE SCOPE OF OUR 5-DAY FORECAST BUT STILL WORTH A MENTION...
MODELS ARE BECOMING MORE INSISTENT THAT A NOR`EASTER OR PERHAPS A
HYBRID/SUBTROPICAL SYSTEM MAY DEVELOP ALONG THE CAROLINA COAST NEXT
WEDNESDAY OR THURSDAY. THIS IS STILL 6 AND 7 DAYS OUT BUT IS WORTHY
OF CONSIDERATION FOR PLANNING PURPOSES GIVEN THE POTENTIAL IMPACT ON
THE MARINE COMMUNITY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT FRIDAY FOR AMZ250-
252-254-256.
&&
$$
SYNOPSIS...01
NEAR TERM...MBB
SHORT TERM...01
LONG TERM...TRA
000
FXUS62 KRAH 181823
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
220 PM EDT THU SEP 18 2008
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL EXTEND INTO THE AREA FROM THE NORTH
THROUGH THE WEEKEND... BRINGING COOL AND DRY CONDITIONS.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 215 PM THURSDAY...
SURFACE HIGH PRESSURE WILL CONTINUE TO NOSE SOUTHWARD THROUGH NC
AS ITS CENTER SHIFTS FROM SOUTHEAST ONTARIO EASTWARD TO OFF THE NOVA
SCOTIA COAST BY THE END OF FRIDAY. WITH ANTICYCLONIC FLOW UP THROUGH
THE MID LEVELS AND A GENERALLY DRY AND SUBSIDING COLUMN... THE QUIET
WEATHER WILL PERSIST THROUGH TOMORROW... ALBEIT WITH A COUPLE OF
CAVEATS.
FOR TONIGHT: THE FLAT RAGGED DAYTIME CLOUDS OVER THE SOUTHERN CWA...
WHERE THE SLIGHTLY HIGHER UPPER 50S/LOWER 60S SURFACE DEW POINTS
PERSIST... WILL SOON DISSIPATE... LEAVING CLEAR SKIES. BUT
TRAJECTORIES SUGGEST THAT AN AREA OF LOW LEVEL MOISTURE NOW NOTED
ACROSS NJ/PA WILL ADVECT SSW TOWARD NC LATE TONIGHT INTO FRIDAY
MORNING... AND MODEL PROJECTIONS ON THE 295K SURFACE SUPPORT THIS.
FORECAST SKY COVER REFLECTS AN INCREASE TO PARTLY CLOUDY SKIES FROM
NORTHEAST TO SOUTHWEST LATE TONIGHT THROUGH FRIDAY MORNING. THIS
MOISTURE DOESN`T APPEAR TO BE TERRIBLY DEEP OR EXPANSIVE HOWEVER...
AND THE MODELS AGREE ON WEAK DOWNGLIDE AT THIS LEVEL... SO IT SHOULD
BE MAINLY SCATTERED IN COVERAG. CURRENT LOWS FROM 55-60 STILL LOOK
REASONABLE GIVEN THE AFTERNOON DROP IN DEW POINTS... THE LATE
ARRIVAL OF THE CLOUDS... AND THE LIGHT BREEZE FROM THE NORTHEAST.
FOR FRIDAY... THE PRESSURE GRADIENT WILL CONTINUE TO TIGHTEN AS THE
SURFACE HIGH MOVES EAST WITH THE BAROCLINIC ZONE STILL SITTING OFF
THE COAST. AS THE LOW LEVEL INVERSION MIXES OUT IN THE MORNING... WE
SHOULD SEE PREVAILING NORTHEAST WINDS QUICKLY JUMP UP TO 10-20 MPH
WITH SOME GUSTS TO 25 MPH. OTHERWISE... THE AFOREMENTIONED BATCH OF
CLOUDS SHOULD CONTINUE MOVING SOUTHWEST TO THE SOUTHERN CWA FRIDAY
MORNING... LEAVING MOSTLY SUNNY SKIES... ALTHOUGH A FEW FLAT
CONVECTIVE CUMULUS MAY POP UP THROUGH THE AFTERNOON. WITH
THICKNESSES EXPECTED TO BE ONLY MARGINALLY LOWER THAN TODAY...
TEMPERATURES SHOULD FOLLOW SUIT... WITH HIGHS IN THE IN THE 76-81
RANGE. -GIH
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
AS OF 200 AM THURSDAY...
FRIDAY AND FRIDAY NIGHT:
THE PRIMARY FCST PROBLEM DURING THIS PERIOD WILL BE WITH HOW BREEZY
WE GET LATE FRIDAY MORNING INTO FRIDAY AFTERNOON. FCST SOUNDINGS
SHOW A TIGHT PRESSURE GRADIENT ACROSS CENTRAL NC...BETWEEN A 1035 MB
SFC HIGH OVER NORTHERN NEW ENGLAND (WITH VERY PRONOUNCED SFC RIDGING
EXTENDING SOUTH INTO THE CAROLINAS) AND A WEAK AREA OF LOW PRESSURE
OFF THE SOUTHEAST COAST. GFS/NAM FCST SOUNDINGS ARE VERY SIMILAR IN
SHOWING 20-25 KNOT NORTHEAST FLOW IN THE MIXED LAYER IN THE COASTAL
PLAIN LATE FRIDAY MORNING INTO FRIDAY AFTERNOON...WITH 15-20 KNOT NE
FLOW FURTHER WEST TOWARD THE WESTERN PIEDMONT. AS SUCH...WILL
FORECAST A SOMEWHAT BREEZY DAY...WITH 15-20 MPH SUSTAINED NORTHEAST
WINDS GUSTING UP TO 25-30 MPH IN THE COASTAL PLAIN...AND AROUND 15
MPH GUSTING UP TO 25 MPH ELSEWHERE. NOW...IF THERE IS EXTENSIVE LOW
STRATUS FRIDAY MORNING...THIS MAY CUT DOWN ON THE GUSTINESS DUE TO
DECREASED INSOLATION/MIXING AFTER SUNRISE...PARTICULARLY IF ANY
STRATUS HANGS AROUND INTO THE EARLY AFTERNOON. AT THIS TIME WILL
FCST PARTLY CLOUDY SKIES IN THE MORNING...BECOMING PARTLY CLOUDY TO
MOSTLY SUNNY IN THE AFTERNOON. WITH COLD ADVECTION...THICKNESSES
BARELY RISE AT ALL DURING THE DAY...AND LOCAL RESEARCH SUGGESTS HIGH
TEMPS WILL RANGE FROM THE LOWER TO MID 70S (73-77F). MAV/MET MOS
GUIDANCE LOOKS TOO WARM FOR THE SYNOPTIC PATTERN AND THICKNESSES...
AND THEREFORE I TRENDED MORE TOWARD THE COOLER MET GUIDANCE...
ALTHOUGH I AM A DEGREE OR TWO COOLER THAN THAT IN SOME CASES. CLEAR
SKIES AND A VERY COOL/DRY AIRMASS IN PLACE SHOULD PROMOTE LOW TEMPS
IN THE MID 50S...STILL NOT AS LOW AS THEY COULD DUE TO ~10 KT
NORTHEAST WINDS THROUGH THE NIGHT GIVEN A TIGHT PRESSURE GRADIENT.
LOWEST TEMPS IN N/NW (WHERE WINDS SHOULD BE LIGHTER) AND HIGHEST IN
THE S/SE.
SATURDAY THROUGH SUNDAY NIGHT:
SFC RIDGING IS EXPECTED TO CONTINUE EXTENDING INTO THE AREA FROM THE
NORTH THROUGH THE WEEKEND...ALTHOUGH THE PRESSURE GRADIENT WILL
WEAKEN QUITE A BIT AS THE SFC HIGH OVER NEW ENGLAND IS BUMPED
OFFSHORE EARLY SAT MORNING BY A DEEP UPPER LEVEL TROUGH MOVING EAST
THROUGH CANADA. BOTH THE GFS/NAM SHOW A WEAK SFC LOW OR BROAD SFC
TROUGH OFFSHORE THE SOUTHEAST AND SOUTHERN MID-ATLANTIC COAST ON
SAT/SUN...ALTHOUGH NEITHER BRING ANY ATLANTIC MOISTURE INTO THE AREA
ON SATURDAY GIVEN THE OFFSHORE LOCATION AND WEAK NATURE OF THE LOW
OR TROUGH. THE NAM TRIES TO STRENGTHEN THE TROUGH INTO A SFC LOW OFF
CAPE HATTERAS ON SUNDAY...WITH MOISTURE WRAPPING BACK INTO SOUTHEAST
VA AND PORTIONS OF CENTRAL NC (PRIMARILY NE COASTAL PLAIN)...
HOWEVER...THE GFS KEEPS THE SYSTEM AS A WEAK/BROAD SFC TROUGH OUT
OVER THE GULF STREAM...WITH ALL OF CENTRAL NC STAYING DRY. AT THIS
TIME PREFER TO KEEP THE FCST DRY ON BOTH SAT/SUN SINCE THE NAM
SOLUTION LOOKS SOMEWHAT ODD. HIGH TEMPS ON SAT IN THE MID/UPPER
70S...INCREASING TO THE UPPER 70S TO LOWER 80S ON SUNDAY AS
THICKNESSES BEGIN TO RECOVER. LOW TEMPS ON SUN/MON MORNINGS IN THE
MID/UPPER 50S TO LOWER 60S. -VINCENT
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 230 AM THURSDAY...
BOTH THE GFS/ECMWF SHOW A DEEP UPPER VORTEX MOVING THROUGH EASTERN
CANADA INTO THE ATLANTIC AT THE BEGINNING OF THE LONG TERM
PERIOD...WITH AN UPPER RIDGE ON ITS HEELS. THIS PROVIDES AN IDEAL
SETUP FOR MASS CONVERGENCE ALOFT...AND STRENGTHENING HIGH PRESSURE
AT THE SFC OVER NEW ENGLAND. WE COULD ACTUALLY SEE A SFC HIGH IN THE
1035-1040 MB RANGE IN NEW ENGLAND BY EARLY/MID WEEK...WITH A STRONG
SFC RIDGE AXIS EXTENDING SOUTH/SW INTO THE MID-ATLANTIC AND
CAROLINAS. BOTH MODELS ARE SHOWING WEAK LOW PRESSURE OR A SFC TROUGH
OFF THE EAST/SE COAST DURING THIS TIME...ALTHOUGH THEY HAVE BEEN
VARYING WITH THE POSITION/STRENGTH OF THE OFFSHORE SFC LOW OR TROUGH
FROM RUN-TO-RUN...LEADING TO SOME UNCERTAINTY WITH THE DETAILS OF
THE FCST. ALTHOUGH FCST SOUNDINGS ARE INITIALLY REASONABLY MOIST
WITH PWAT VALUES AROUND 1.00" ON MONDAY (INCREASED MID/UPPER LEVEL
MOISTURE)...THEY BEGIN TO DRY OUT THEREAFTER...DROPPING TO
0.50-0.75" FOR TUE/WED. THIS WILL OBVIOUSLY DEPEND ON THE POSITION
AND STRENGTH OF ANY OFFSHORE SFC LOW/TROUGH...THOUGH. BOTH THE
GFS/ECMWF SHOW A VERY TIGHT PRESSURE GRADIENT BY TUE/WED...WITH
DOWNRIGHT BREEZY/WINDY CONDITIONS WITH 25-35 KNOTS IN THE MIXED
LAYER. THIS FAR OUT IN THE FCST...WILL KEEP NORTHEAST WINDS IN THE
10-15 KNOT RANGE AT MOST...ALTHOUGH I WOULD NOT BE SURPRISED TO SEE
SUSTAINED WINDS CLOSE TO WIND ADVISORY CRITERIA IN THE EASTERN HALF
OF THE AREA IF THE GFS FCST SOUNDINGS VERIFY.
ALSO...AT THIS TIME...WILL KEEP THE FCST DRY THROUGH THE EXTENDED
PERIOD WITH SUCH A STRONG COOL/DRY SFC RIDGE AXIS EXTENDING INTO THE
AREA...AND ANY OFFSHORE SFC LOW OR TROUGH EXPECTED TO REMAIN FAR
ENOUGH OUT TO KEEP ANY WRAP-AROUND MOISTURE ALONG THE COAST OR
OFFSHORE. HIGH TEMPS SHOULD START OUT NEAR NORMAL ON MONDAY...
DROPPING TO BELOW NORMAL BY TUE/WED. SOME OF THE GFS FCST SOUNDINGS
SHOW HIGH TEMPS STRUGGLING TO GET OUT OF THE 60S ON TUE/WED...BUT AT
THIS TIME...WILL TREND TO JUST A FEW DEGREES BELOW NORMAL...WITH
HIGHS IN THE LOWER/MID 70S AND LOWS IN THE MID/UPPER 50S ON
TUE/WED/THU. -VINCENT
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 215 PM THURSDAY...
WHILE VFR CONDITIONS WILL PREVAIL OVER MUCH OF THE NEXT 24 HOURS...
A PERIOD OF MVFR OR IFR CLOUDS ARE POSSIBLE LATE TONIGHT INTO EARLY
FRIDAY MORNING... AND LOW LEVEL WIND SHEAR WILL BE A THREAT LATE
TONIGHT.
AN AREA OF LOW LEVEL MOISTURE WILL ADVECT TO THE SSW INTO CENTRAL NC
LATE TONIGHT INTO FRIDAY MORNING. THIS MOISTURE WILL NOT BE
PARTICULARLY DEEP OR EXPANSIVE HOWEVER... SO MOSTLY SCATTERED CLOUDS
WITH 1200-2000 FT BASES ARE EXPECTED. BUT THEY MAY BRIEFLY GO BROKEN
BETWEEN 09Z AND 14Z... SO AVIATION INTERESTS SHOULD KEEP A CLOSE EYE
ON THE LATEST CONDITIONS AND TERMINAL FORECASTS. ALSO... AS THE
SURFACE BASED INVERSION FORMS LATE TONIGHT... NORTHEAST WINDS ALOFT
AT 1000-2000 FT AGL WILL INCREASE IN RESPONSE TO THE INCREASING
PRESSURE GRADIENT BETWEEN THE SURFACE HIGH TO THE NORTH AND LOWER
PRESSURES TO THE SOUTHEAST. LOW LEVEL WIND SHEAR IS EXPECTED TO
DEVELOP... MOST PREDOMINANTLY AT FAY/RWI. THIS SHOULD MIX OUT
SHORTLY AFTER DAYBREAK WITH HEATING AND MIXING TAKING PLACE. AFTER
14Z... SCATTERED TO BROKEN CLOUDS WITH BASES AOA 3200 FT ARE
EXPECTED THROUGH EARLY FRIDAY AFTERNOON. -GIH
ANOTHER PERIOD OF CLOUDINESS MAY OCCUR SATURDAY NIGHT INTO SUNDAY AS
MOISTURE POOLS ALONG A TROUGH POSITIONED ALONG THE COAST. THE CLOUDS
WILL BE MOST LIKELY IN THE EAST VERSUS THE WEST. -WSS
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RWH
NEAR TERM...HARTFIELD
SHORT TERM...VINCENT
LONG TERM...VINCENT
AVIATION...HARTFIELD/WSS
000
FXUS62 KILM 181722
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
120 PM EDT THU SEP 18 2008
.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE CAROLINAS THROUGH THE WEEKEND
AND BRING COOLER THAN NORMAL TEMPERATURES TO THE REGION. A TROUGH
OF LOW PRESSURE WILL DEVELOP OFFSHORE AND MOVE CLOSE ENOUGH TO THE
AREA TO INCREASE THE CHANCE OF SHOWERS LATE IN THE WEEKEND AND
INTO EARLY NEXT WEEK. TEMPERATURES WILL REMAIN SLIGHTLY BELOW
NORMAL THROUGH THE PERIOD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM THURSDAY...
LOWERED CLOUD COVER TO NEAR ZERO IN THE VERY NEAR TERM AND LOW
ENOUGH TO BRING `SUNNY` IN TEXT PRODS. 12Z RAOBS AND SAT IMAGERY
SHOW THAT ONLY VERY FLAT CU WILL FORM JUST UNDER THE INVERSION AND
BE UNDER 20 PERCENT IN COVERAGE. NO OTHER CHANGES.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...FORECAST REMAINS ESSENTIALLY THE SAME AS HIGH
PRESSURE ANCHORED OVER THE NORTHEAST WILL BE THE DOMINANT PLAYER
THROUGH THE PERIOD. THE GFS IS STILL SHOWING A RIBBON OF HIGHER RH
OFFSHORE WHILE GENERATING A SOME LIGHT QPF. WILL KEEP THE AREA DRY
UNTIL LATE SATURDAY WHEN SOME OF THE ACTIVITY MAY WONDER ONSHORE.
AT LEAST INITIALLY...THE MET NUMBERS SEEM TO HAVE A BETTER HANDLE
ON THE NEW AIRMASS AND WILL LEAN TOWARD THEM THROUGHOUT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 3 AM THURSDAY...THE LATEST OPERATIONAL GFS CONTINUES TO SHOW
COASTAL TROUGH DEVELOPMENT WHILE KEEPING MOST OF THE PRECIPITATION
OFFSHORE. HPC MANUAL PROGS SHOW THE TROUGH SOMEWHAT OFFSHORE AS
WELL. NO REASON TO MAKE SIGNIFICANT CHANGES TO THE FORECAST THIS
MORNING. MAINTAINED LOW CHANCE POPS ACROSS COASTAL COUNTIES
BASICALLY THROUGHOUT AND TEMPERATURES AT OR SLIGHTLY BELOW NORMAL.
&&
.AVIATION /18Z THURSDAY THROUGH MONDAY/...
CLEAR SKY EXPECTED THROUGH THE TAF CYCLE. ONLY CHANGE REQUIRING FM
GROUPS WILL BE TO SHOW DIURNAL TREND IN WINDS...A DROPOFF CLOSE TO
SUNSET AND AN INCREASE AFTER SUNRISE TOMORROW. NORTHEASTERLY
GRADIENT REMAINS MODERATELY STRONG SO GUSTY BREEZE EXPECTED AGAIN
FRIDAY.
OUTLOOK THROUGH MONDAY...VFR GENERALLY EXPECTED. HIGH PRESSURE
BUILDS EAST OF NOVA SCOTIA OVER THE WEEKEND. THE FLOW AROUND THIS
HIGH WILL KEEP A FETCH OF AIR OFF THE OCEAN. THE GFS HINTS AT A
COASTAL TROUGH DEVELOPING WITH SHOWERS ALONG COASTAL AREAS AS EARLY
AS SATURDAY AFTERNOON. IF THIS PANS OUT COASTAL TERMINALS MAY SEE
ISOLATED SHOWERS LATE SATURDAY AND SUNDAY BEFORE A NEW AREA OF HIGH
PRESSURE BUILDS SOUTH OUT OF CANADA BY MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM THURSDAY...NE FLOW 15 TO 20 KT WILL CONTINUE TODAY AND
TONIGHT WITH AN INCREASE IN WINDS LATER THIS EVENING AS SFC HIGH
OVER NEW ENGLAND STRENGTHENS AND BUILDS DOWN THE COAST. SPEEDS WILL
APPROACH...AND MAY EXCEED...25 KT BY THE END OF THE PERIOD. SEAS
WILL CONTINUE RUNNING 3 TO 5 FT IN RESPONSE TO PERIOD OF EXTENDED NE
FLOW. INCREASE IN SPEEDS LATER TONIGHT WILL PUSH SEAS ACROSS NC
ZONES TO 6 FT BY THE END OF THE PERIOD.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...THE LATEST GFS SHOWS AN AREA OF STRONGER 925MB
WINDS ACROSS THE WATERS AT THE BEGINNING OF THE PERIOD...NEAR 30
KNOTS WHICH BASICALLY PERSISTS THROUGH SATURDAY AFTERNOON. THIS WILL
EQUATE TO 20-25 KNOTS AT THE SURFACE. SPEEDS STEP SLIGHTLY BY EARLY
SUNDAY MORNING CLOSER TO 20 KNOTS BUT WILL STILL ADVERTISE A RANGE
OF 20-25 KNOTS.
SEAS WILL BE FIRMLY IN SMALL CRAFT RANGES AT THE BEGINNING OF THE
PERIOD AND WILL CONTINUE THROUGH SUNDAY MORNING. BASED ON THIS AND
THE FACT THE MODELS HAVE BEEN VERY CONSISTENT IN ADVERTISING THIS
SCENARIO A FEW PERIODS NOW...WILL GO AHEAD AND HOIST SMALL CRAFT
ADVISORY ALL ZONES BEGINNING FRIDAY.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 AM THURSDAY...NE FLOW WILL PERSIST THROUGH MONDAY. SPEEDS
MAY RELAX JUST ENOUGH TO ALLOW SEAS TO DIP BELOW FLAG
CRITERIA...OTHERWISE NO CHANGES.
&&
.TIDES/COASTAL FLOODING...
SYNOPTIC SET UP WARRANTS A LOOK AT COASTAL FLOODING THREAT.
TIDES ARE RUNNING A BIT ABOVE NORMAL AT SPRINGMAID PIER AND OYSTER
LANDING...FEEL CONFIDENT THAT LEVELS WILL REMAIN BELOW THRESHOLDS
FOR COASTAL FLOOD ADVISORY AT THIS POINT. WILL CONTINUE TO MONITOR
CLOSELY HOWEVER.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT FRIDAY FOR
AMZ250- 252-254-256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...MBB/III
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...MBB
TIDES/COASTAL FLOODING...SHK/III
000
FXUS62 KILM 181550
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1138 AM EDT THU SEP 18 2008
.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE CAROLINAS THROUGH THE WEEKEND
AND BRING COOLER THAN NORMAL TEMPERATURES TO THE REGION. A TROUGH
OF LOW PRESSURE WILL DEVELOP OFFSHORE AND MOVE CLOSE ENOUGH TO THE
AREA TO INCREASE THE CHANCE OF SHOWERS LATE IN THE WEEKEND AND
INTO EARLY NEXT WEEK. TEMPERATURES WILL REMAIN SLIGHTLY BELOW
NORMAL THROUGH THE PERIOD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM THURSDAY...
LOWERED CLOUD COVER TO NEAR ZERO IN THE VERY NEAR TERM AND LOW
ENOUGH TO BRING `SUNNY` IN TEXT PRODS. 12Z RAOBS AND SAT IMAGERY
SHOW THAT ONLY VERY FLAT CU WILL FORM JUST UNDER THE INVERSION AND
BE UNDER 20 PERCENT IN COVERAGE. NO OTHER CHANGES.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...FORECAST REMAINS ESSENTIALLY THE SAME AS HIGH
PRESSURE ANCHORED OVER THE NORTHEAST WILL BE THE DOMINANT PLAYER
THROUGH THE PERIOD. THE GFS IS STILL SHOWING A RIBBON OF HIGHER RH
OFFSHORE WHILE GENERATING A SOME LIGHT QPF. WILL KEEP THE AREA DRY
UNTIL LATE SATURDAY WHEN SOME OF THE ACTIVITY MAY WONDER ONSHORE.
AT LEAST INITIALLY...THE MET NUMBERS SEEM TO HAVE A BETTER HANDLE
ON THE NEW AIRMASS AND WILL LEAN TOWARD THEM THROUGHOUT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 3 AM THURSDAY...THE LATEST OPERATIONAL GFS CONTINUES TO SHOW
COASTAL TROUGH DEVELOPMENT WHILE KEEPING MOST OF THE PRECIPITATION
OFFSHORE. HPC MANUAL PROGS SHOW THE TROUGH SOMEWHAT OFFSHORE AS
WELL. NO REASON TO MAKE SIGNIFICANT CHANGES TO THE FORECAST THIS
MORNING. MAINTAINED LOW CHANCE POPS ACROSS COASTAL COUNTIES
BASICALLY THROUGHOUT AND TEMPERATURES AT OR SLIGHTLY BELOW NORMAL.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
LIGHT BR HAS DEVELOPED AT LBT BUT WILL BE SHORT LIVED. LATER THIS
MORNING TIGHT GRADIENT AND MIXING RESULT IN BREEZY CONDITIONS.
PINCHED GRADIENT ALONG THE IMMEDIATE COAST WILL RESULT IN HIGHEST
WINDS/GUSTS AT COASTAL SITES. GRADIENT RELAXES A BIT IN THE AFTN
WITH SPEEDS STARTING TO EASE UP. LEFTOVER MOISTURE BETWEEN 3K AND
5K MAY RESULT IN A FEW FAIR WEATHER CU DURING PEAK DAYTIME
HEATING.
OUTLOOK THROUGH MONDAY...VFR GENERALLY EXPECTED. HIGH PRESSURE
BUILDS EAST OF NOVA SCOTIA OVER THE WEEKEND. THE FLOW AROUND THIS
HIGH WILL KEEP A FETCH OF AIR OFF THE OCEAN. THE GFS HINTS AT A
COASTAL TROUGH DEVELOPING WITH SHOWERS ALONG COASTAL AREAS AS EARLY
AS SATURDAY AFTERNOON. IF THIS PANS OUT COASTAL TERMINALS MAY SEE
ISOLATED SHOWERS LATE SATURDAY AND SUNDAY BEFORE A NEW AREA OF HIGH
PRESSURE BUILDS SOUTH OUT OF CANADA BY MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM THURSDAY...NE FLOW 15 TO 20 KT WILL CONTINUE TODAY AND
TONIGHT WITH AN INCREASE IN WINDS LATER THIS EVENING AS SFC HIGH
OVER NEW ENGLAND STRENGTHENS AND BUILDS DOWN THE COAST. SPEEDS WILL
APPROACH...AND MAY EXCEED...25 KT BY THE END OF THE PERIOD. SEAS
WILL CONTINUE RUNNING 3 TO 5 FT IN RESPONSE TO PERIOD OF EXTENDED NE
FLOW. INCREASE IN SPEEDS LATER TONIGHT WILL PUSH SEAS ACROSS NC
ZONES TO 6 FT BY THE END OF THE PERIOD.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...THE LATEST GFS SHOWS AN AREA OF STRONGER 925MB
WINDS ACROSS THE WATERS AT THE BEGINNING OF THE PERIOD...NEAR 30
KNOTS WHICH BASICALLY PERSISTS THROUGH SATURDAY AFTERNOON. THIS WILL
EQUATE TO 20-25 KNOTS AT THE SURFACE. SPEEDS STEP SLIGHTLY BY EARLY
SUNDAY MORNING CLOSER TO 20 KNOTS BUT WILL STILL ADVERTISE A RANGE
OF 20-25 KNOTS.
SEAS WILL BE FIRMLY IN SMALL CRAFT RANGES AT THE BEGINNING OF THE
PERIOD AND WILL CONTINUE THROUGH SUNDAY MORNING. BASED ON THIS AND
THE FACT THE MODELS HAVE BEEN VERY CONSISTENT IN ADVERTISING THIS
SCENARIO A FEW PERIODS NOW...WILL GO AHEAD AND HOIST SMALL CRAFT
ADVISORY ALL ZONES BEGINNING FRIDAY.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 AM THURSDAY...NE FLOW WILL PERSIST THROUGH MONDAY. SPEEDS
MAY RELAX JUST ENOUGH TO ALLOW SEAS TO DIP BELOW FLAG
CRITERIA...OTHERWISE NO CHANGES.
&&
.TIDES/COASTAL FLOODING...
SYNOPTIC SET UP WARRANTS A LOOK AT COASTAL FLOODING THREAT.
TIDES ARE RUNNING A BIT ABOVE NORMAL AT SPRINGMAID PIER AND OYSTER
LANDING...FEEL CONFIDENT THAT LEVELS WILL REMAIN BELOW THRESHOLDS
FOR COASTAL FLOOD ADVISORY AT THIS POINT. WILL CONTINUE TO MONITOR
CLOSELY HOWEVER.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT FRIDAY FOR
AMZ250- 252-254-256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...MBB/III
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...III
TIDES/COASTAL FLOODING...SHK/III
000
FXUS62 KRAH 181458
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1055 AM EDT THU SEP 18 2008
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL EXTEND INTO THE AREA FROM THE NORTH
THROUGH THE WEEKEND... BRINGING COOL AND DRY CONDITIONS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1055 AM THURSDAY...
VERY LITTLE NEW DATA... OBSERVED OR MODEL OUTPUT... PROMPTS A
SIGNIFICANT DEVIATION FROM THE CURRENT FORECAST. THE LATEST SURFACE
AND UPPER AIR ANALYSES SHOW STACKED RIDGING AND A SUBSIDING AND
GENERALLY DRY COLUMN OVER NC. MINOR PERTURBATIONS WERE NOTED ON THE
700 MB AND 500 MB ANALYSES DROPPING THROUGH THE REGION... BUT GIVEN
THE DRY AIR ALOFT THESE SHOULD HAVE NO IMPACT ON SENSIBLE WEATHER.
ONLY TWO NOTABLE CHANGES WERE MADE TO THE REST OF TODAY FORECAST.
BASED ON OBSERVED THICKNESSES... MORNING TEMPERATURE TRENDS... AND
EXPECTATIONS OF A DRY ADIABATIC LOW LEVEL LAPSE RATE... HIGHS HAVE
BEEN RAISED TO 80-84. ALSO... 925 MB DEW POINTS ARE WELL INTO THE
40S UPSTREAM... SO WITH GOOD VERTICAL MIXING... SURFACE DEW POINTS
SHOULD EASILY DROP INTO THE UPPER 40S TO LOWER 50S... A DOWNWARD
BUMP FROM THE PREVIOUS FORECAST. OTHERWISE... WE SHOULD SEE
CONTINUED MOSTLY CLEAR SKIES WITH MINIMAL FLAT CONVECTIVE CUMULUS.
-GIH
AS OF 100 AM THURSDAY...
TONIGHT:
LOW LEVEL NORTHEAST FLOW FURTHER INCREASES OVERNIGHT AS THE PRESSURE
GRADIENT CONTINUES TO TIGHTEN AS THE INVERTED SFC RIDGE BECOMES
FIRMLY ESTABLISHED ACROSS THE MID-ATLANTIC AND CAROLINAS. FCST
SOUNDINGS SHOW 30 KNOT FLOW AS LOW AS 1500-2000 FT AGL TONIGHT. WITH
OTHERWISE EXCELLENT RADIATIONAL COOLING CONDS...SHOULD SEE NE WINDS
NO MORE THAN ~10 KNOTS AS MIXING IS MITIGATED BY THE NOCTURNAL
INVERSION. FCST SOUNDINGS HINT AT THE POSSIBILITY OF LOW STRATUS
DEVELOPING IN THE STRONG NE LOW LEVEL FLOW BETWEEN 06-12Z FRIDAY
MORNING...AND WILL TRY TO ACCOUNT FOR THIS BY SHOWING PARTLY CLOUDY
SKIES BY SUNRISE...ALTHOUGH IT IS POSSIBLE SOME AREAS COULD BE
MOSTLY CLOUDY. THE POSSIBILITY OF LOW STRATUS AND THE 5-10 KNOT NE
WINDS SHOULD KEEP TEMPS FROM BOTTOMING OUT AS MUCH AS THEY WOULD
OTHERWISE (GIVEN THE AIRMASS IN PLACE)...AND WILL FCST LOWS IN THE
MID/UPPER 50S TO 60F. -VINCENT
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
AS OF 200 AM THURSDAY...
FRIDAY AND FRIDAY NIGHT:
THE PRIMARY FCST PROBLEM DURING THIS PERIOD WILL BE WITH HOW BREEZY
WE GET LATE FRIDAY MORNING INTO FRIDAY AFTERNOON. FCST SOUNDINGS
SHOW A TIGHT PRESSURE GRADIENT ACROSS CENTRAL NC...BETWEEN A 1035 MB
SFC HIGH OVER NORTHERN NEW ENGLAND (WITH VERY PRONOUNCED SFC RIDGING
EXTENDING SOUTH INTO THE CAROLINAS) AND A WEAK AREA OF LOW PRESSURE
OFF THE SOUTHEAST COAST. GFS/NAM FCST SOUNDINGS ARE VERY SIMILAR IN
SHOWING 20-25 KNOT NORTHEAST FLOW IN THE MIXED LAYER IN THE COASTAL
PLAIN LATE FRIDAY MORNING INTO FRIDAY AFTERNOON...WITH 15-20 KNOT NE
FLOW FURTHER WEST TOWARD THE WESTERN PIEDMONT. AS SUCH...WILL
FORECAST A SOMEWHAT BREEZY DAY...WITH 15-20 MPH SUSTAINED NORTHEAST
WINDS GUSTING UP TO 25-30 MPH IN THE COASTAL PLAIN...AND AROUND 15
MPH GUSTING UP TO 25 MPH ELSEWHERE. NOW...IF THERE IS EXTENSIVE LOW
STRATUS FRIDAY MORNING...THIS MAY CUT DOWN ON THE GUSTINESS DUE TO
DECREASED INSOLATION/MIXING AFTER SUNRISE...PARTICULARLY IF ANY
STRATUS HANGS AROUND INTO THE EARLY AFTERNOON. AT THIS TIME WILL
FCST PARTLY CLOUDY SKIES IN THE MORNING...BECOMING PARTLY CLOUDY TO
MOSTLY SUNNY IN THE AFTERNOON. WITH COLD ADVECTION...THICKNESSES
BARELY RISE AT ALL DURING THE DAY...AND LOCAL RESEARCH SUGGESTS HIGH
TEMPS WILL RANGE FROM THE LOWER TO MID 70S (73-77F). MAV/MET MOS
GUIDANCE LOOKS TOO WARM FOR THE SYNOPTIC PATTERN AND THICKNESSES...
AND THEREFORE I TRENDED MORE TOWARD THE COOLER MET GUIDANCE...
ALTHOUGH I AM A DEGREE OR TWO COOLER THAN THAT IN SOME CASES. CLEAR
SKIES AND A VERY COOL/DRY AIRMASS IN PLACE SHOULD PROMOTE LOW TEMPS
IN THE MID 50S...STILL NOT AS LOW AS THEY COULD DUE TO ~10 KT
NORTHEAST WINDS THROUGH THE NIGHT GIVEN A TIGHT PRESSURE GRADIENT.
LOWEST TEMPS IN N/NW (WHERE WINDS SHOULD BE LIGHTER) AND HIGHEST IN
THE S/SE.
SATURDAY THROUGH SUNDAY NIGHT:
SFC RIDGING IS EXPECTED TO CONTINUE EXTENDING INTO THE AREA FROM THE
NORTH THROUGH THE WEEKEND...ALTHOUGH THE PRESSURE GRADIENT WILL
WEAKEN QUITE A BIT AS THE SFC HIGH OVER NEW ENGLAND IS BUMPED
OFFSHORE EARLY SAT MORNING BY A DEEP UPPER LEVEL TROUGH MOVING EAST
THROUGH CANADA. BOTH THE GFS/NAM SHOW A WEAK SFC LOW OR BROAD SFC
TROUGH OFFSHORE THE SOUTHEAST AND SOUTHERN MID-ATLANTIC COAST ON
SAT/SUN...ALTHOUGH NEITHER BRING ANY ATLANTIC MOISTURE INTO THE AREA
ON SATURDAY GIVEN THE OFFSHORE LOCATION AND WEAK NATURE OF THE LOW
OR TROUGH. THE NAM TRIES TO STRENGTHEN THE TROUGH INTO A SFC LOW OFF
CAPE HATTERAS ON SUNDAY...WITH MOISTURE WRAPPING BACK INTO SOUTHEAST
VA AND PORTIONS OF CENTRAL NC (PRIMARILY NE COASTAL PLAIN)...
HOWEVER...THE GFS KEEPS THE SYSTEM AS A WEAK/BROAD SFC TROUGH OUT
OVER THE GULF STREAM...WITH ALL OF CENTRAL NC STAYING DRY. AT THIS
TIME PREFER TO KEEP THE FCST DRY ON BOTH SAT/SUN SINCE THE NAM
SOLUTION LOOKS SOMEWHAT ODD. HIGH TEMPS ON SAT IN THE MID/UPPER
70S...INCREASING TO THE UPPER 70S TO LOWER 80S ON SUNDAY AS
THICKNESSES BEGIN TO RECOVER. LOW TEMPS ON SUN/MON MORNINGS IN THE
MID/UPPER 50S TO LOWER 60S. -VINCENT
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 230 AM THURSDAY...
BOTH THE GFS/ECMWF SHOW A DEEP UPPER VORTEX MOVING THROUGH EASTERN
CANADA INTO THE ATLANTIC AT THE BEGINNING OF THE LONG TERM
PERIOD...WITH AN UPPER RIDGE ON ITS HEELS. THIS PROVIDES AN IDEAL
SETUP FOR MASS CONVERGENCE ALOFT...AND STRENGTHENING HIGH PRESSURE
AT THE SFC OVER NEW ENGLAND. WE COULD ACTUALLY SEE A SFC HIGH IN THE
1035-1040 MB RANGE IN NEW ENGLAND BY EARLY/MID WEEK...WITH A STRONG
SFC RIDGE AXIS EXTENDING SOUTH/SW INTO THE MID-ATLANTIC AND
CAROLINAS. BOTH MODELS ARE SHOWING WEAK LOW PRESSURE OR A SFC TROUGH
OFF THE EAST/SE COAST DURING THIS TIME...ALTHOUGH THEY HAVE BEEN
VARYING WITH THE POSITION/STRENGTH OF THE OFFSHORE SFC LOW OR TROUGH
FROM RUN-TO-RUN...LEADING TO SOME UNCERTAINTY WITH THE DETAILS OF
THE FCST. ALTHOUGH FCST SOUNDINGS ARE INITIALLY REASONABLY MOIST
WITH PWAT VALUES AROUND 1.00" ON MONDAY (INCREASED MID/UPPER LEVEL
MOISTURE)...THEY BEGIN TO DRY OUT THEREAFTER...DROPPING TO
0.50-0.75" FOR TUE/WED. THIS WILL OBVIOUSLY DEPEND ON THE POSITION
AND STRENGTH OF ANY OFFSHORE SFC LOW/TROUGH...THOUGH. BOTH THE
GFS/ECMWF SHOW A VERY TIGHT PRESSURE GRADIENT BY TUE/WED...WITH
DOWNRIGHT BREEZY/WINDY CONDITIONS WITH 25-35 KNOTS IN THE MIXED
LAYER. THIS FAR OUT IN THE FCST...WILL KEEP NORTHEAST WINDS IN THE
10-15 KNOT RANGE AT MOST...ALTHOUGH I WOULD NOT BE SURPRISED TO SEE
SUSTAINED WINDS CLOSE TO WIND ADVISORY CRITERIA IN THE EASTERN HALF
OF THE AREA IF THE GFS FCST SOUNDINGS VERIFY.
ALSO...AT THIS TIME...WILL KEEP THE FCST DRY THROUGH THE EXTENDED
PERIOD WITH SUCH A STRONG COOL/DRY SFC RIDGE AXIS EXTENDING INTO THE
AREA...AND ANY OFFSHORE SFC LOW OR TROUGH EXPECTED TO REMAIN FAR
ENOUGH OUT TO KEEP ANY WRAP-AROUND MOISTURE ALONG THE COAST OR
OFFSHORE. HIGH TEMPS SHOULD START OUT NEAR NORMAL ON MONDAY...
DROPPING TO BELOW NORMAL BY TUE/WED. SOME OF THE GFS FCST SOUNDINGS
SHOW HIGH TEMPS STRUGGLING TO GET OUT OF THE 60S ON TUE/WED...BUT AT
THIS TIME...WILL TREND TO JUST A FEW DEGREES BELOW NORMAL...WITH
HIGHS IN THE LOWER/MID 70S AND LOWS IN THE MID/UPPER 50S ON
TUE/WED/THU. -VINCENT
&&
.AVIATION /13Z THURSDAY THROUGH TUESDAY/...
AS OF 845 AM THURSDAY...
HIGH PRESSURE WILL BUILD INTO CENTRAL NC THROUGH FRIDAY. THIS
WEATHER SYSTEM WILL RESULT IN DRY AND PLEASANTLY COOL AIR MASS. MVFR
CONDITIONS DUE TO FOG WILL LIFT/DISSIPATE BEFORE 14Z. OTHERWISE...
EXPECT VFR CONDITIONS THROUGH 12Z FRIDAY.
TONIGHT...NEAR SURFACE WINDS WILL BE LIGHT OUT OF THE NE. WHILE
WINDS BETWEEN 1000-2000FT WILL VEER TO A E-NE DIRECTION AND INCREASE
IN SPEED TO 20-25KTS. THIS MARGINAL LOW LEVEL WIND SHEAR EPISODE
WILL BE MOST PROMINENT BETWEEN 06Z-12Z FRIDAY.
THIS INCREASE IN WINDS JUST ABOVE THE SURFACE WILL ALSO ADVECT
ATLANTIC MOISTURE INTO THE REGION. THIS MAY RESULT IN A DECK OF
STRATUS FRIDAY MORNING THROUGH EARLY AFTERNOON. OTHERWISE...VFR
CONDITIONS SHOULD OCCUR LATE FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON.
ANOTHER PERIOD OF CLOUDINESS MAY OCCUR SATURDAY NIGHT INTO SUNDAY AS
MOISTURE POOLS ALONG A TROUGH POSITIONED ALONG THE COAST. THE CLOUDS
WILL BE MOST LIKELY IN THE EAST VERSUS THE WEST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RWH
NEAR TERM...HARTFIELD/VINCENT
SHORT TERM...VINCENT
LONG TERM...VINCENT
AVIATION...WSS
000
FXUS62 KMHX 181344
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
944 AM EDT THU SEP 18 2008
.SYNOPSIS...
SFC HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE NORTH THROUGH
EARLY SAT. WEAK SFC LOW PRES WILL DEVELOP OFFSHORE SAT INTO SUN. A
MUCH STRONGER AREA OF HIGH PRES WILL BUILD INTO THE AREA NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FORECAST ON TRACK SO ONLY MINOR TWEAKS TO SKY GRIDS THIS MORNING
AND TO REMOVE POPS FROM SRN COASTAL WATERS. PLEASANT...DRY DAY
EXPECTED WITH LIMITED SKY COVER INLAND AND CLOUDS GRADUALLY
PUSHING OFFSHORE THE OUTER BANKS.
PREVIOUS DISCUSSION...
MID/UPPER LEVEL TROUGH WILL DAMPEN AND MOVE OFFSHORE
LATER THIS MORNING WITH SFC HIGH PRES BUILDING IN FROM THE NORTH
THROUGH THIS EVENING. SKIES CURRENTLY PARTLY TO MOSTLY CLOUDY OVER
EASTERN SECTIONS BUT WILL BECOME CLEAR ACROSS THE ENTIRE CWA BY
MID/LATE MORNING AS DRIER AIR CONTINUES TO FILTER INTO THE AREA.
NORTH WINDS WILL PREVAIL TODAY AND WITH DECENT MIXING EXPECT
BREEZY CONDITIONS DEVELOPING BY AFTERNOON. HIGHS WILL RANGE FROM
NEAR 80 INLAND TO THE UPPER 70S BEACHES AND OUTER BANKS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
HIGH PRES WILL CONTINUE TO RIDGE INTO THE AREA FROM THE NORTH
THROUGH FRI BEFORE WEAK LOW PRES DEVELOPS OFFSHORE TO THE SE FRI
EVENING. LOW LEVEL FLOW WILL VEER TO THE NE TONIGHT INTO FRI WITH
GRADIENT TIGHTENING BETWEEN THE SFC LOW OFFSHORE AND HIGH PRES TO
THE NE. BREEZY CONDITIONS EXPECTED INLAND WITH WINDY CONDITIONS
ALONG THE BEACHES AND OUTER BANKS ON FRI. COULD BE LOOKING AT WIND
ADVISORY CRITERIA ALONG THE OUTER BANKS LATE TONIGHT THROUGH FRI
BUT GIVEN WEAKER SFC LOW OFFSHORE PER GFS WILL KEEP WINDS JUST
BELOW ADVISORY CRITERIA AND LET DAY SHIFT RE-EVALUATE. PROLONGED
NE FLOW COUPLED WITH HIGH ASTRONOMICAL TIDES MAY ALSO RESULT IN
HIGH SURF CONDITIONS ALONG WITH MINOR BEACH EROSION AND OCEAN
OVERWASH MAINLY ALONG EAST FACING BEACHES FRI/FRI NIGHT. HIGH
THREAT OF RIP CURRENTS WILL INCREASE ALONG AREA BEACHES THROUGH
FRI. LOW LEVEL NE FLOW WILL LIKELY RESULT IN SOME STRATUS
DEVELOPING LATE TONIGHT INTO FRI BUT KEPT SKIES PARTLY CLOUDY
FOR NOW.
GRADIENT WEAKENS ON SAT AS WEAK SFC LOW OFFSHORE LIFTS NE. LOW
LEVEL FLOW WILL REMAIN N/NE THROUGH SAT NIGHT. MODEL TIME
SECTIONS/SOUNDINGS INDICATE LOW LEVEL STRATUS FILLING IN ACROSS
MUCH OF THE AREA AND WENT WITH MOSTLY CLOUDY SKIES FOR SAT.
SLIGHT CHANCE POPS WERE RETAINED ALONG COASTAL SECTIONS THROUGH
THE PERIOD WITH WEAK SFC LOW OFFSHORE. TEMPS WILL REMAIN SLIGHTLY
BELOW NORMAL THROUGH THE PERIOD WITH OVERNIGHT LOWS UPPER 50S/LOW
60S INLAND TO THE MID/UPPER 60S BEACHES AND OUTER BANKS. HIGHS
MOSTLY IN THE 70S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
EXTENDED PERIOD WILL FEATURE A MUCH STRONGER AREA OF HIGH
PRES AFFECTING THE AREA WITH ANOTHER AREA OF LOW PRES DEVELOPING
OFFSHORE TO THE SE BY WED. TIGHT GRADIENT BETWEEN THESE TWO
FEATURES WILL AGAIN RESULT IN BREEZY/WINDY CONDITIONS DEVELOPING
TUE INTO WED. NO CHANGE TO EXTENDED GRIDS ATTM BUT FORECAST TEMPS
MAY NEED TO BE LOWERED AS MODELS SHOW LOWER THICKNESSES DEVELOPING
BY TUE AND WED WITH A DEEP UPPER VORTEX MOVING EAST ACROSS EASTERN
CANADA.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS PREDOMINANT NEXT 24HRS AS DRY FALL-LIKE AIR MOVES
INTO THE REGION. WINDS WILL STEADILY PICK UP LATER TODAY AS HIGH
PRES BUILDS TO THE NORTH.
NE FLOW WILL CONTINUE OVER THE REGION...POSS BRINGING IN SOME
STRATUS COOLER MARINE AIR LATE IN WEEK...BUT TERMINALS LIKELY
PREDOMINANT VFR.
&&
.MARINE...
AS OF 9 AM THURSDAY...AS HIGH PRES BUILDS TO THE N GRADIENT WILL
GRADUALLY TIGHTEN ALONG THE CST. EXPECT WINDS TO INCREASE TODAY AND
REACH 20 TO 25 KTS MOST WTRS THIS AFTN. HAVE DELAYED THE SCA A BIT
TIL AROUND 18Z MOST WTRS GIVEN CURRENT CONDITIONS AND OUTPUT FROM
06Z MDLS. WINDS SHLD CONT TO INCREASE OVERNIGHT INTO FRI WITH
SUSTAINED WINDS AROUND 25 KTS EXPECTED MOST AREAS FRI. THIS WILL
BUILD SEAS TO 7 TO 10 FT CENTRAL AND N...AND 5 TO 8 FT S ON FRI. WILL
HAVE TO CONSIDER HIGH SURF ADVISORY FOR AT LEAST NRN BEACHES FRI.
PREVIOUS DISC...FIVE YEARS TO THE DAY OF HURRICANE ISABEL LANDFALL IN
EASTERN NC (GC). CONDITIONS SIG BETTER TODAY THAN IT WAS THEN
(SEAS OVER 40FT!)...BUT STILL LOOKING FOR HEADLINES FOR SCA WINDS
20 TO 25 KT THIS AFTERNOON. STRONG HIGH PRES WILL BUILD TO THE N
TODAY...INCREASING THE PRES GRAD OVER THE REGION. AS THE HIGH
STRENGTHENS INTO FRI...LOOK FOR WINDS APPROACHING GALE FORCE. HAVE
GONE ON THE HIGHER SIDE OF GUIDANCE DUE TO LIKELIHOOD OF DECENT
MIXING...BUT STILL LOOKS TOO CLOSE TO CALL ON THE NEAR GALE
CONDITIONS FRI. THE HIGH WILL SLIDE E AND WINDS WILL WEAKEN OVER
THE WEEKEND. THE NEXT HIGH EXP EARLY NEXT WEEK LOOKS STRONGER THAN
THE CURRENT ONE...WITH MODELS IN FAIRLY GOOD AGREEMENT. THIS IS
NOT GOOD...CONSIDERING CONDITIONS NEAR GALE EXP WITH THIS
HIGH...WE COULD SEE LONG DURATION OF GALE FORCE WINDS AND WIND
SEAS COMBINED WITH SWELL FROM THE NE FETCH PUSHING SEAS EASILY
INTO THE DOUBLE DIGITS. HAVE TRENDED THIS WAY IN THE FCST...THOUGH
DON`T USUALLY LIKE TO GO SO HIGH WITH CONDITIONS THIS FAR OUT
THERE IS ABOVE NORMAL CONFIDENCE IN AT LEAST 10 FT SEAS AND STRONG
AND PERSISTENT NE WINDS EARLY NEXT WEEK. WAVEWATCH SHOWS NEAR 30
FT BY THU...BUT THAT IS BEYOND THIS FCST SCOPE. OVERALL...WITH
THESE TWO COOL-STRONG HIGH BUILDING IN OVER THE WARM COASTAL
WATERS LOOK FOR DETERIORATING SEAS THROUGH THE REST OF THE FCST
PERIOD. WITH HIGH ASTRONOMICAL TIDES COMBINED WITH ROUGH SEAS
COULD SEE HIGH SURF CONDITIONS FRI AFT. WINDS LOOK JUST UNDER WIND
ADV FOR OBX. FOR EARLY NEXT WEEK EXP HIGH SURF CONDITIONS ALONG
OBX. CAN`T RULE OUT MINOR SOUNDSIDE WATER RISES AND POSSIBLE WIND
ADV.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 11 AM EDT
SATURDAY FOR AMZ130-135.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 7 PM EDT
MONDAY FOR AMZ150-152-154-156.
SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 5 PM EDT
SATURDAY FOR AMZ158.
&&
$$
SYNOPSIS...JW
NEAR TERM...MW/JW
SHORT TERM...JW
LONG TERM...JW
AVIATION...RF/SJ
MARINE...RF/SJ
000
FXUS62 KRAH 181256
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
855 AM EDT THU SEP 18 2008
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL BEGIN TO EXTEND INTO THE AREA FROM THE
NORTH TODAY...BRINGING COOL AND DRY CONDITIONS TO CENTRAL NORTH
CAROLINA TODAY THROUGH SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 100 AM THURSDAY...
SFC ANALYSIS THIS MORNING SHOWED 1030 MB HIGH PRESSURE CENTERED JUST
NORTH OF THE UPPER GREAT LAKES. A SFC RIDGE AXIS EXTENDED S/SE
THROUGH THE OH VALLEY INTO THE MID-ATLANTIC. ACROSS CENTRAL NC...
DEWPOINTS RANGED FROM THE MID 50S TO LOWER 60S. ALOFT...00Z RAOB
ANALYSIS AND WV IMAGERY SHOWED THE UPPER TROUGH AXIS THAT HAS BEEN
TO OUR WEST FINALLY SHIFTING EAST ACROSS THE AREA.
TODAY:
1030 MB HIGH PRESSURE CURRENTLY JUST NORTH OF THE UPPER GREAT LAKES
IS PROGGED TO SHIFT EAST INTO NEW ENGLAND BY THIS EVENING...
STRENGTHENING THE PRESSURE GRADIENT ACROSS THE MID-ATLANTIC AND
CAROLINAS AS THE FAMILIAR INVERTED SFC RIDGE NOSES DOWN THE LEE OF
THE APPALACHIANS. WITH AN INCREASED DRY NNE LOW LEVEL FLOW...IN
ADDITION TO SUBSIDENCE ALOFT IN THE WAKE OF THE UPPER TROUGH
CURRENTLY PASSING THROUGH THE AREA...EXPECT DRY CONDITIONS TODAY...
WITH FCST SOUNDINGS SHOWING PWAT VALUES IN THE 0.50-0.75" RANGE.
ALTHOUGH SOME CLOUD COVER WILL BE AROUND DURING THE MORNING HOURS...
PRIMARILY IN THE EAST...WE SHOULD SEE CLEAR OR MOSTLY CLEAR SKIES BY
AFTERNOON. FCST SOUNDINGS ARE UNANIMOUS IN SHOWING 15-20 KNOTS
THROUGHOUT THE MIXED LAYER THIS AFTERNOON IN THE COASTAL PLAIN...
AROUND 15 KNOTS IN THE TRIANGLE...AND 10-15 KNOTS IN THE WESTERN
PIEDMONT. AS SUCH...WE SHOULD SEE SOMEWHAT BREEZY SUSTAINED NNE OR
NE WINDS IN THE 15-20 MPH RANGE IN THE COASTAL PLAIN...WITH LOWER
VALUES IN THE 10-15 MPH RANGE BY THE TIME YOU GET TO THE FAR WESTERN
PIEDMONT. A BLEND OF GFS/NAM THICKNESSES TODAY GIVES VALUES FROM
ROUGHLY 1375 METERS THIS MORNING TO 1385 METERS THIS AFTERNOON...
WHICH SUPPORTS HIGH TEMPS IN THE UPPER 70S TO NEAR 80F. MOS GUIDANCE
IS A FEW DEGREES WARMER. GIVEN 10-20 MPH NNE/NE FLOW THIS
AFTERNOON...FEEL THAT TEMPS SHOULD BE LOWER THAN MOS GUIDANCE AND
MORE IN LINE WITH WHAT THE THICKNESSES SUGGEST...AND WILL FCST HIGHS
RANGING FROM 78-81F.
TONIGHT:
LOW LEVEL NORTHEAST FLOW FURTHER INCREASES OVERNIGHT AS THE PRESSURE
GRADIENT CONTINUES TO TIGHTEN AS THE INVERTED SFC RIDGE BECOMES
FIRMLY ESTABLISHED ACROSS THE MID-ATLANTIC AND CAROLINAS. FCST
SOUNDINGS SHOW 30 KNOT FLOW AS LOW AS 1500-2000 FT AGL TONIGHT. WITH
OTHERWISE EXCELLENT RADIATIONAL COOLING CONDS...SHOULD SEE NE WINDS
NO MORE THAN ~10 KNOTS AS MIXING IS MITIGATED BY THE NOCTURNAL
INVERSION. FCST SOUNDINGS HINT AT THE POSSIBILITY OF LOW STRATUS
DEVELOPING IN THE STRONG NE LOW LEVEL FLOW BETWEEN 06-12Z FRIDAY
MORNING...AND WILL TRY TO ACCOUNT FOR THIS BY SHOWING PARTLY CLOUDY
SKIES BY SUNRISE...ALTHOUGH IT IS POSSIBLE SOME AREAS COULD BE
MOSTLY CLOUDY. THE POSSIBILITY OF LOW STRATUS AND THE 5-10 KNOT NE
WINDS SHOULD KEEP TEMPS FROM BOTTOMING OUT AS MUCH AS THEY WOULD
OTHERWISE (GIVEN THE AIRMASS IN PLACE)...AND WILL FCST LOWS IN THE
MID/UPPER 50S TO 60F. -VINCENT
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
AS OF 200 AM THURSDAY...
FRIDAY AND FRIDAY NIGHT:
THE PRIMARY FCST PROBLEM DURING THIS PERIOD WILL BE WITH HOW BREEZY
WE GET LATE FRIDAY MORNING INTO FRIDAY AFTERNOON. FCST SOUNDINGS
SHOW A TIGHT PRESSURE GRADIENT ACROSS CENTRAL NC...BETWEEN A 1035 MB
SFC HIGH OVER NORTHERN NEW ENGLAND (WITH VERY PRONOUNCED SFC RIDGING
EXTENDING SOUTH INTO THE CAROLINAS) AND A WEAK AREA OF LOW PRESSURE
OFF THE SOUTHEAST COAST. GFS/NAM FCST SOUNDINGS ARE VERY SIMILAR IN
SHOWING 20-25 KNOT NORTHEAST FLOW IN THE MIXED LAYER IN THE COASTAL
PLAIN LATE FRIDAY MORNING INTO FRIDAY AFTERNOON...WITH 15-20 KNOT NE
FLOW FURTHER WEST TOWARD THE WESTERN PIEDMONT. AS SUCH...WILL
FORECAST A SOMEWHAT BREEZY DAY...WITH 15-20 MPH SUSTAINED NORTHEAST
WINDS GUSTING UP TO 25-30 MPH IN THE COASTAL PLAIN...AND AROUND 15
MPH GUSTING UP TO 25 MPH ELSEWHERE. NOW...IF THERE IS EXTENSIVE LOW
STRATUS FRIDAY MORNING...THIS MAY CUT DOWN ON THE GUSTINESS DUE TO
DECREASED INSOLATION/MIXING AFTER SUNRISE...PARTICULARLY IF ANY
STRATUS HANGS AROUND INTO THE EARLY AFTERNOON. AT THIS TIME WILL
FCST PARTLY CLOUDY SKIES IN THE MORNING...BECOMING PARTLY CLOUDY TO
MOSTLY SUNNY IN THE AFTERNOON. WITH COLD ADVECTION...THICKNESSES
BARELY RISE AT ALL DURING THE DAY...AND LOCAL RESEARCH SUGGESTS HIGH
TEMPS WILL RANGE FROM THE LOWER TO MID 70S (73-77F). MAV/MET MOS
GUIDANCE LOOKS TOO WARM FOR THE SYNOPTIC PATTERN AND THICKNESSES...
AND THEREFORE I TRENDED MORE TOWARD THE COOLER MET GUIDANCE...
ALTHOUGH I AM A DEGREE OR TWO COOLER THAN THAT IN SOME CASES. CLEAR
SKIES AND A VERY COOL/DRY AIRMASS IN PLACE SHOULD PROMOTE LOW TEMPS
IN THE MID 50S...STILL NOT AS LOW AS THEY COULD DUE TO ~10 KT
NORTHEAST WINDS THROUGH THE NIGHT GIVEN A TIGHT PRESSURE GRADIENT.
LOWEST TEMPS IN N/NW (WHERE WINDS SHOULD BE LIGHTER) AND HIGHEST IN
THE S/SE.
SATURDAY THROUGH SUNDAY NIGHT:
SFC RIDGING IS EXPECTED TO CONTINUE EXTENDING INTO THE AREA FROM THE
NORTH THROUGH THE WEEKEND...ALTHOUGH THE PRESSURE GRADIENT WILL
WEAKEN QUITE A BIT AS THE SFC HIGH OVER NEW ENGLAND IS BUMPED
OFFSHORE EARLY SAT MORNING BY A DEEP UPPER LEVEL TROUGH MOVING EAST
THROUGH CANADA. BOTH THE GFS/NAM SHOW A WEAK SFC LOW OR BROAD SFC
TROUGH OFFSHORE THE SOUTHEAST AND SOUTHERN MID-ATLANTIC COAST ON
SAT/SUN...ALTHOUGH NEITHER BRING ANY ATLANTIC MOISTURE INTO THE AREA
ON SATURDAY GIVEN THE OFFSHORE LOCATION AND WEAK NATURE OF THE LOW
OR TROUGH. THE NAM TRIES TO STRENGTHEN THE TROUGH INTO A SFC LOW OFF
CAPE HATTERAS ON SUNDAY...WITH MOISTURE WRAPPING BACK INTO SOUTHEAST
VA AND PORTIONS OF CENTRAL NC (PRIMARILY NE COASTAL PLAIN)...
HOWEVER...THE GFS KEEPS THE SYSTEM AS A WEAK/BROAD SFC TROUGH OUT
OVER THE GULF STREAM...WITH ALL OF CENTRAL NC STAYING DRY. AT THIS
TIME PREFER TO KEEP THE FCST DRY ON BOTH SAT/SUN SINCE THE NAM
SOLUTION LOOKS SOMEWHAT ODD. HIGH TEMPS ON SAT IN THE MID/UPPER
70S...INCREASING TO THE UPPER 70S TO LOWER 80S ON SUNDAY AS
THICKNESSES BEGIN TO RECOVER. LOW TEMPS ON SUN/MON MORNINGS IN THE
MID/UPPER 50S TO LOWER 60S. -VINCENT
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 230 AM THURSDAY...
BOTH THE GFS/ECMWF SHOW A DEEP UPPER VORTEX MOVING THROUGH EASTERN
CANADA INTO THE ATLANTIC AT THE BEGINNING OF THE LONG TERM
PERIOD...WITH AN UPPER RIDGE ON ITS HEELS. THIS PROVIDES AN IDEAL
SETUP FOR MASS CONVERGENCE ALOFT...AND STRENGTHENING HIGH PRESSURE
AT THE SFC OVER NEW ENGLAND. WE COULD ACTUALLY SEE A SFC HIGH IN THE
1035-1040 MB RANGE IN NEW ENGLAND BY EARLY/MID WEEK...WITH A STRONG
SFC RIDGE AXIS EXTENDING SOUTH/SW INTO THE MID-ATLANTIC AND
CAROLINAS. BOTH MODELS ARE SHOWING WEAK LOW PRESSURE OR A SFC TROUGH
OFF THE EAST/SE COAST DURING THIS TIME...ALTHOUGH THEY HAVE BEEN
VARYING WITH THE POSITION/STRENGTH OF THE OFFSHORE SFC LOW OR TROUGH
FROM RUN-TO-RUN...LEADING TO SOME UNCERTAINTY WITH THE DETAILS OF
THE FCST. ALTHOUGH FCST SOUNDINGS ARE INITIALLY REASONABLY MOIST
WITH PWAT VALUES AROUND 1.00" ON MONDAY (INCREASED MID/UPPER LEVEL
MOISTURE)...THEY BEGIN TO DRY OUT THEREAFTER...DROPPING TO
0.50-0.75" FOR TUE/WED. THIS WILL OBVIOUSLY DEPEND ON THE POSITION
AND STRENGTH OF ANY OFFSHORE SFC LOW/TROUGH...THOUGH. BOTH THE
GFS/ECMWF SHOW A VERY TIGHT PRESSURE GRADIENT BY TUE/WED...WITH
DOWNRIGHT BREEZY/WINDY CONDITIONS WITH 25-35 KNOTS IN THE MIXED
LAYER. THIS FAR OUT IN THE FCST...WILL KEEP NORTHEAST WINDS IN THE
10-15 KNOT RANGE AT MOST...ALTHOUGH I WOULD NOT BE SURPRISED TO SEE
SUSTAINED WINDS CLOSE TO WIND ADVISORY CRITERIA IN THE EASTERN HALF
OF THE AREA IF THE GFS FCST SOUNDINGS VERIFY.
ALSO...AT THIS TIME...WILL KEEP THE FCST DRY THROUGH THE EXTENDED
PERIOD WITH SUCH A STRONG COOL/DRY SFC RIDGE AXIS EXTENDING INTO THE
AREA...AND ANY OFFSHORE SFC LOW OR TROUGH EXPECTED TO REMAIN FAR
ENOUGH OUT TO KEEP ANY WRAP-AROUND MOISTURE ALONG THE COAST OR
OFFSHORE. HIGH TEMPS SHOULD START OUT NEAR NORMAL ON MONDAY...
DROPPING TO BELOW NORMAL BY TUE/WED. SOME OF THE GFS FCST SOUNDINGS
SHOW HIGH TEMPS STRUGGLING TO GET OUT OF THE 60S ON TUE/WED...BUT AT
THIS TIME...WILL TREND TO JUST A FEW DEGREES BELOW NORMAL...WITH
HIGHS IN THE LOWER/MID 70S AND LOWS IN THE MID/UPPER 50S ON
TUE/WED/THU. -VINCENT
&&
.AVIATION /13Z THURSDAY THROUGH TUESDAY/...
AS OF 845 AM THURSDAY...
HIGH PRESSURE WILL BUILD INTO CENTRAL NC THROUGH FRIDAY. THIS
WEATHER SYSTEM WILL RESULT IN DRY AND PLEASANTLY COOL AIR MASS. MVFR
CONDITIONS DUE TO FOG WILL LIFT/DISSIPATE BEFORE 14Z. OTHERWISE...
EXPECT VFR CONDITIONS THROUGH 12Z FRIDAY.
TONIGHT...NEAR SURFACE WINDS WILL BE LIGHT OUT OF THE NE. WHILE
WINDS BETWEEN 1000-2000FT WILL VEER TO A E-NE DIRECTION AND INCREASE
IN SPEED TO 20-25KTS. THIS MARGINAL LOW LEVEL WIND SHEAR EPISODE
WILL BE MOST PROMINENT BETWEEN 06Z-12Z FRIDAY.
THIS INCREASE IN WINDS JUST ABOVE THE SURFACE WILL ALSO ADVECT
ATLANTIC MOISTURE INTO THE REGION. THIS MAY RESULT IN A DECK OF
STRATUS FRIDAY MORNING THROUGH EARLY AFTERNOON. OTHERWISE...VFR
CONDITIONS SHOULD OCCUR LATE FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON.
ANOTHER PERIOD OF CLOUDINESS MAY OCCUR SATURDAY NIGHT INTO SUNDAY AS
MOISTURE POOLS ALONG A TROUGH POSITIONED ALONG THE COAST. THE CLOUDS
WILL BE MOST LIKELY IN THE EAST VERSUS THE WEST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...VINCENT
LONG TERM...VINCENT
AVIATION...WSS
000
FXUS62 KILM 181138
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
738 AM EDT THU SEP 18 2008
.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE CAROLINAS THROUGH THE WEEKEND
AND BRING COOLER THAN NORMAL TEMPERATURES TO THE REGION. A TROUGH
OF LOW PRESSURE WILL DEVELOP OFFSHORE AND MOVE CLOSE ENOUGH TO THE
AREA TO INCREASE THE CHANCE OF SHOWERS LATE IN THE WEEKEND AND
INTO EARLY NEXT WEEK. TEMPERATURES WILL REMAIN SLIGHTLY BELOW
NORMAL THROUGH THE PERIOD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM THURSDAY...AXIS OF WEAK UPPER TROF WILL BE OVER THE AREA
TODAY AS MID LEVEL RIDGE AND ASSOCIATED DRY AIR BUILD IN FROM THE
WNW. ONLY A THIN LAYER OF MOISTURE IN FORECAST SOUNDINGS TODAY
TRAPPED BETWEEN 7H RIDGE AND DRYING BOUNDARY LAYER. WOULD EXPECT
SOME AFTN CU DEVELOPMENT BUT SKIES WILL REMAIN MOSTLY SUNNY. PWS
UNDER AN INCH AND AFOREMENTIONED MID LEVEL RIDGING WILL PREVENT CU
FROM GAINING ENOUGH VERTICAL EXTENT TO POSE A PRECIP THREAT. BIGGER
STORY WILL BE BREEZY CONDITIONS WITH PINCHED GRADIENT IN THE AREA AS
SFC HIGH TO THE N BUILDS S. SPEEDS WILL BEGIN TO DECREASE DURING THE
AFTN HOURS AS GRADIENT STARTS TO RELAX. COMBINATION OF ENHANCED NE
FLOW AND COOL AIR MASS WILL KEEP HIGHS ABOUT A CAT BELOW CLIMO.
GRADIENT BEGINS TO TIGHTEN UP OVERNIGHT AS SFC HIGH...NOW OVER
NE...STARTS TO STRENGTHEN AND BUILD DOWN THE COAST. WELL MIXED
BOUNDARY LAYER WILL PREVENT OPTIMAL RADIATIONAL COOLING
CONDITIONS...BUT TEMPS WILL STILL RUN A CAT OR 2 BELOW CLIMO.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...FORECAST REMAINS ESSENTIALLY THE SAME AS HIGH
PRESSURE ANCHORED OVER THE NORTHEAST WILL BE THE DOMINANT PLAYER
THROUGH THE PERIOD. THE GFS IS STILL SHOWING A RIBBON OF HIGHER RH
OFFSHORE WHILE GENERATING A SOME LIGHT QPF. WILL KEEP THE AREA DRY
UNTIL LATE SATURDAY WHEN SOME OF THE ACTIVITY MAY WONDER ONSHORE.
AT LEAST INITIALLY...THE MET NUMBERS SEEM TO HAVE A BETTER HANDLE
ON THE NEW AIRMASS AND WILL LEAN TOWARD THEM THROUGHOUT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 3 AM THURSDAY...THE LATEST OPERATIONAL GFS CONTINUES TO SHOW COASTAL
TROUGH DEVELOPMENT WHILE KEEPING MOST OF THE PRECIPITATION OFFSHORE.
HPC MANUAL PROGS SHOW THE TROUGH SOMEWHAT OFFSHORE AS WELL. NO
REASON TO MAKE SIGNIFICANT CHANGES TO THE FORECAST THIS MORNING.
MAINTAINED LOW CHANCE POPS ACROSS COASTAL COUNTIES BASICALLY
THROUGHOUT AND TEMPERATURES AT OR SLIGHTLY BELOW NORMAL.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
LIGHT BR HAS DEVELOPED AT LBT BUT WILL BE SHORT LIVED. LATER THIS
MORNING TIGHT GRADIENT AND MIXING RESULT IN BREEZY CONDITIONS.
PINCHED GRADIENT ALONG THE IMMEDIATE COAST WILL RESULT IN HIGHEST
WINDS/GUSTS AT COASTAL SITES. GRADIENT RELAXES A BIT IN THE AFTN
WITH SPEEDS STARTING TO EASE UP. LEFTOVER MOISTURE BETWEEN 3K AND
5K MAY RESULT IN A FEW FAIR WEATHER CU DURING PEAK DAYTIME
HEATING.
OUTLOOK THROUGH MONDAY...VFR GENERALLY EXPECTED. HIGH PRESSURE
BUILDS EAST OF NOVA SCOTIA OVER THE WEEKEND. THE FLOW AROUND THIS
HIGH WILL KEEP A FETCH OF AIR OFF THE OCEAN. THE GFS HINTS AT A
COASTAL TROUGH DEVELOPING WITH SHOWERS ALONG COASTAL AREAS AS EARLY
AS SATURDAY AFTERNOON. IF THIS PANS OUT COASTAL TERMINALS MAY SEE
ISOLATED SHOWERS LATE SATURDAY AND SUNDAY BEFORE A NEW AREA OF HIGH
PRESSURE BUILDS SOUTH OUT OF CANADA BY MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM THURSDAY...NE FLOW 15 TO 20 KT WILL CONTINUE TODAY AND
TONIGHT WITH AN INCREASE IN WINDS LATER THIS EVENING AS SFC HIGH
OVER NEW ENGLAND STRENGTHENS AND BUILDS DOWN THE COAST. SPEEDS WILL
APPROACH...AND MAY EXCEED...25 KT BY THE END OF THE PERIOD. SEAS
WILL CONTINUE RUNNING 3 TO 5 FT IN RESPONSE TO PERIOD OF EXTENDED NE
FLOW. INCREASE IN SPEEDS LATER TONIGHT WILL PUSH SEAS ACROSS NC
ZONES TO 6 FT BY THE END OF THE PERIOD.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...THE LATEST GFS SHOWS AN AREA OF STRONGER 925MB
WINDS ACROSS THE WATERS AT THE BEGINNING OF THE PERIOD...NEAR 30
KNOTS WHICH BASICALLY PERSISTS THROUGH SATURDAY AFTERNOON. THIS WILL
EQUATE TO 20-25 KNOTS AT THE SURFACE. SPEEDS STEP SLIGHTLY BY EARLY
SUNDAY MORNING CLOSER TO 20 KNOTS BUT WILL STILL ADVERTISE A RANGE
OF 20-25 KNOTS.
SEAS WILL BE FIRMLY IN SMALL CRAFT RANGES AT THE BEGINNING OF THE
PERIOD AND WILL CONTINUE THROUGH SUNDAY MORNING. BASED ON THIS AND
THE FACT THE MODELS HAVE BEEN VERY CONSISTENT IN ADVERTISING THIS
SCENARIO A FEW PERIODS NOW...WILL GO AHEAD AND HOIST SMALL CRAFT ADVISORY
ALL ZONES BEGINNING FRIDAY.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 AM THURSDAY...NE FLOW WILL PERSIST THROUGH MONDAY. SPEEDS
MAY RELAX JUST ENOUGH TO ALLOW SEAS TO DIP BELOW FLAG
CRITERIA...OTHERWISE NO CHANGES.
&&
.TIDES/COASTAL FLOODING...
SYNOPTIC SET UP WARRANTS A LOOK AT COASTAL FLOODING THREAT.
TIDES ARE RUNNING A BIT ABOVE NORMAL AT SPRINGMAID PIER AND OYSTER
LANDING...FEEL CONFIDENT THAT LEVELS WILL REMAIN BELOW THRESHOLDS
FOR COASTAL FLOOD ADVISORY AT THIS POINT. WILL CONTINUE TO MONITOR
CLOSELY HOWEVER.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT FRIDAY FOR AMZ250-
252-254-256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...III
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...III
TIDES/COASTAL FLOODING...SHK/III
000
FXUS62 KMHX 180847
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
447 AM EDT THU SEP 18 2008
.SYNOPSIS...
SFC HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE NORTH THROUGH
EARLY SAT. WEAK SFC LOW PRES WILL DEVELOP OFFSHORE SAT INTO SUN. A
MUCH STRONGER AREA OF HIGH PRES WILL BUILD INTO THE AREA NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MID/UPPER LEVEL TROUGH WILL DAMPEN AND MOVE OFFSHORE LATER THIS
MORNING WITH SFC HIGH PRES BUILDING IN FROM THE NORTH THROUGH THIS
EVENING. SKIES CURRENTLY PARTLY TO MOSTLY CLOUDY OVER EASTERN
SECTIONS BUT WILL BECOME CLEAR ACROSS THE ENTIRE CWA BY MID/LATE
MORNING AS DRIER AIR CONTINUES TO FILTER INTO THE AREA. NORTH
WINDS WILL PREVAIL TODAY AND WITH DECENT MIXING EXPECT BREEZY
CONDITIONS DEVELOPING BY AFTERNOON. HIGHS WILL RANGE FROM NEAR
80 INLAND TO THE UPPER 70S BEACHES AND OUTER BANKS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
HIGH PRES WILL CONTINUE TO RIDGE INTO THE AREA FROM THE NORTH
THROUGH FRI BEFORE WEAK LOW PRES DEVELOPS OFFSHORE TO THE SE FRI
EVENING. LOW LEVEL FLOW WILL VEER TO THE NE TONIGHT INTO FRI WITH
GRADIENT TIGHTENING BETWEEN THE SFC LOW OFFSHORE AND HIGH PRES TO
THE NE. BREEZY CONDITIONS EXPECTED INLAND WITH WINDY CONDITIONS
ALONG THE BEACHES AND OUTER BANKS ON FRI. COULD BE LOOKING AT WIND
ADVISORY CRITERIA ALONG THE OUTER BANKS LATE TONIGHT THROUGH FRI
BUT GIVEN WEAKER SFC LOW OFFSHORE PER GFS WILL KEEP WINDS JUST
BELOW ADVISORY CRITERIA AND LET DAY SHIFT RE-EVALUATE. PROLONGED
NE FLOW COUPLED WITH HIGH ASTRONOMICAL TIDES MAY ALSO RESULT IN
HIGH SURF CONDITIONS ALONG WITH MINOR BEACH EROSION AND OCEAN
OVERWASH MAINLY ALONG EAST FACING BEACHES FRI/FRI NIGHT. HIGH
THREAT OF RIP CURRENTS WILL INCREASE ALONG AREA BEACHES THROUGH
FRI. LOW LEVEL NE FLOW WILL LIKELY RESULT IN SOME STRATUS
DEVELOPING LATE TONIGHT INTO FRI BUT KEPT SKIES PARTLY CLOUDY
FOR NOW.
GRADIENT WEAKENS ON SAT AS WEAK SFC LOW OFFSHORE LIFTS NE. LOW
LEVEL FLOW WILL REMAIN N/NE THROUGH SAT NIGHT. MODEL TIME
SECTIONS/SOUNDINGS INDICATE LOW LEVEL STRATUS FILLING IN ACROSS
MUCH OF THE AREA AND WENT WITH MOSTLY CLOUDY SKIES FOR SAT.
SLIGHT CHANCE POPS WERE RETAINED ALONG COASTAL SECTIONS THROUGH
THE PERIOD WITH WEAK SFC LOW OFFSHORE. TEMPS WILL REMAIN SLIGHTLY
BELOW NORMAL THROUGH THE PERIOD WITH OVERNIGHT LOWS UPPER 50S/LOW
60S INLAND TO THE MID/UPPER 60S BEACHES AND OUTER BANKS. HIGHS
MOSTLY IN THE 70S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
EXTENDED PERIOD WILL FEATURE A MUCH STRONGER AREA OF HIGH
PRES AFFECTING THE AREA WITH ANOTHER AREA OF LOW PRES DEVELOPING
OFFSHORE TO THE SE BY WED. TIGHT GRADIENT BETWEEN THESE TWO
FEATURES WILL AGAIN RESULT IN BREEZY/WINDY CONDITIONS DEVELOPING
TUE INTO WED. NO CHANGE TO EXTENDED GRIDS ATTM BUT FORECAST TEMPS
MAY NEED TO BE LOWERED AS MODELS SHOW LOWER THICKNESSES DEVELOPING
BY TUE AND WED WITH A DEEP UPPER VORTEX MOVING EAST ACROSS EASTERN
CANADA.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS PREDOMINANT NEXT 24HRS AS DRY FALL-LIKE AIR MOVES
INTO THE REGION...ERODING CLOUDS. SOME MID/HIGH CLOUDS WILL
DIMINISH TODAY...LEAVING CLEAR SKIES IN THEIR WAKE. WINDS WILL
STEADILY PICK UP OVERNIGHT INTO FRI.
NE FLOW WILL CONTINUE OVER THE REGION...OCCASIONALLY BRINGING IN
SOME LOW STRATUS IN COOLER MARINE AIR...BUT TERMINALS LIKELY
PREDOMINANT VFR.
&&
.MARINE...
FIVE YEARS TO THE DAY OF HURRICANE ISABEL LANDFALL IN EASTERN NC
(GC). CONDITIONS SIG BETTER TODAY THAN IT WAS THEN (SEAS OVER
40FT!)...BUT STILL LOOKING FOR HEADLINES FOR SCA WINDS 20 TO 25
KT THIS AFTERNOON. STRONG HIGH PRES WILL BUILD TO THE N
TODAY...INCREASING THE PRES GRAD OVER THE REGION. AS THE HIGH
STRENGTHENS INTO FRI...LOOK FOR WINDS APPROACHING GALE FORCE.
HAVE GONE ON THE HIGHER SIDE OF GUIDANCE DUE TO LIKELIHOOD OF
DECENT MIXING...BUT STILL LOOKS TOO CLOSE TO CALL ON THE NEAR GALE
CONDITIONS FRI. THE HIGH WILL SLIDE E AND WINDS WILL WEAKEN OVER
THE WEEKEND. THE NEXT HIGH EXP EARLY NEXT WEEK LOOKS STRONGER THAN
THE CURRENT ONE...WITH MODELS IN FAIRLY GOOD AGREEMENT. THIS IS
NOT GOOD...CONSIDERING CONDITIONS NEAR GALE EXP WITH THIS
HIGH...WE COULD SEE LONG DURATION OF GALE FORCE WINDS AND WIND
SEAS COMBINED WITH SWELL FROM THE NE FETCH PUSHING SEAS EASILY
INTO THE DOUBLE DIGITS. HAVE TRENDED THIS WAY IN THE FCST...THOUGH
DON`T USUALLY LIKE TO GO SO HIGH WITH CONDITIONS THIS FAR OUT
THERE IS ABOVE NORMAL CONFIDENCE IN AT LEAST 10 FT SEAS AND STRONG
AND PERSISTENT NE WINDS EARLY NEXT WEEK. WAVEWATCH SHOWS NEAR 30
FT BY THU...BUT THAT IS BEYOND THIS FCST SCOPE. OVERALL...WITH
THESE TWO COOL-STRONG HIGH BUILDING IN OVER THE WARM COASTAL
WATERS LOOK FOR DETERIORATING SEAS THROUGH THE REST OF THE FCST
PERIOD. WITH HIGH ASTRONOMICAL TIDES COMBINED WITH ROUGH SEAS
COULD SEE HIGH SURF CONDITIONS FRI AFT. WINDS LOOK JUST UNDER WIND
ADV FOR OBX. FOR EARLY NEXT WEEK EXP HIGH SURF CONDITIONS ALONG
OBX. CAN`T RULE OUT MINOR SOUNDSIDE WATER RISES AND POSSIBLE WIND
ADV.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 11 AM EDT
SATURDAY FOR AMZ130-135.
SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 7 PM EDT
MONDAY FOR AMZ150-152-154-156.
SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 5 PM EDT
SATURDAY FOR AMZ158.
&&
$$
SYNOPSIS...JW
NEAR TERM...JW
SHORT TERM...JW
LONG TERM...JW
AVIATION...SJ
MARINE...SJ
000
FXUS62 KILM 180707
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
307 AM EDT THU SEP 18 2008
.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE CAROLINAS THROUGH THE WEEKEND
AND BRING COOLER THAN NORMAL TEMPERATURES TO THE REGION. A TROUGH
OF LOW PRESSURE WILL DEVELOP OFFSHORE AND MOVE CLOSE ENOUGH TO THE
AREA TO INCREASE THE CHANCE OF SHOWERS LATE IN THE WEEKEND AND
INTO EARLY NEXT WEEK. TEMPERATURES WILL REMAIN SLIGHTLY BELOW
NORMAL THROUGH THE PERIOD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM THURSDAY...AXIS OF WEAK UPPER TROF WILL BE OVER THE AREA
TODAY AS MID LEVEL RIDGE AND ASSOCIATED DRY AIR BUILD IN FROM THE
WNW. ONLY A THIN LAYER OF MOISTURE IN FORECAST SOUNDINGS TODAY
TRAPPED BETWEEN 7H RIDGE AND DRYING BOUNDARY LAYER. WOULD EXPECT
SOME AFTN CU DEVELOPMENT BUT SKIES WILL REMAIN MOSTLY SUNNY. PWS
UNDER AN INCH AND AFOREMENTIONED MID LEVEL RIDGING WILL PREVENT CU
FROM GAINING ENOUGH VERTICAL EXTENT TO POSE A PRECIP THREAT. BIGGER
STORY WILL BE BREEZY CONDITIONS WITH PINCHED GRADIENT IN THE AREA AS
SFC HIGH TO THE N BUILDS S. SPEEDS WILL BEGIN TO DECREASE DURING THE
AFTN HOURS AS GRADIENT STARTS TO RELAX. COMBINATION OF ENHANCED NE
FLOW AND COOL AIR MASS WILL KEEP HIGHS ABOUT A CAT BELOW CLIMO.
GRADIENT BEGINS TO TIGHTEN UP OVERNIGHT AS SFC HIGH...NOW OVER
NE...STARTS TO STRENGTHEN AND BUILD DOWN THE COAST. WELL MIXED
BOUNDARY LAYER WILL PREVENT OPTIMAL RADIATIONAL COOLING
CONDITIONS...BUT TEMPS WILL STILL RUN A CAT OR 2 BELOW CLIMO.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...FORECAST REMAINS ESSENTIALLY THE SAME AS HIGH
PRESSURE ANCHORED OVER THE NORTHEAST WILL BE THE DOMINANT PLAYER
THROUGH THE PERIOD. THE GFS IS STILL SHOWING A RIBBON OF HIGHER RH
OFFSHORE WHILE GENERATING A SOME LIGHT QPF. WILL KEEP THE AREA DRY
UNTIL LATE SATURDAY WHEN SOME OF THE ACTIVITY MAY WONDER ONSHORE.
AT LEAST INITIALLY...THE MET NUMBERS SEEM TO HAVE A BETTER HANDLE
ON THE NEW AIRMASS AND WILL LEAN TOWARD THEM THROUGHOUT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 3 AM THURSDAY...THE LATEST OPERATIONAL GFS CONTINUES TO SHOW COASTAL
TROUGH DEVELOPMENT WHILE KEEPING MOST OF THE PRECIPITATION OFFSHORE.
HPC MANUAL PROGS SHOW THE TROUGH SOMEWHAT OFFSHORE AS WELL. NO
REASON TO MAKE SIGNIFICANT CHANGES TO THE FORECAST THIS MORNING.
MAINTAINED LOW CHANCE POPS ACROSS COASTAL COUNTIES BASICALLY
THROUGHOUT AND TEMPERATURES AT OR SLIGHTLY BELOW NORMAL.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
SKIES WILL CONTINUE GRADUAL CLEARING FROM FROM WEST TO EAST
OVERNIGHT WITH WINDS REMAINING LIGHT AND FROM THE NE. MAY SEE SOME
BRIEF PATCHY BR OVERNIGHT BUT COMBINATION OF DRY AND WELL MIXED
BOUNDARY LAYER WILL KEEP OCCURRENCES SHORT LIVED.
TIGHT GRADIENT WILL RESULT IN BREEZY CONDITIONS TODAY. PINCHED
GRADIENT ALONG THE IMMEDIATE COAST WILL RESULT IN HIGH WINDS AND
GUSTS AT COASTAL SITES. GRADIENT RELAXES A BIT IN THE AFTN WITH
SPEEDS STARTING TO EASE UP. LEFTOVER MOISTURE BETWEEN 3K AND 5K
MAY RESULT IN A FEW FAIR WEATHER CU DURING PEAK DAYTIME HEATING.
OUTLOOK THROUGH MONDAY...VFR GENERALLY EXPECTED. HIGH PRESSURE
BUILDS EAST OF NOVA SCOTIA OVER THE WEEKEND. THE FLOW AROUND THIS
HIGH WILL KEEP A FETCH OF AIR OFF THE OCEAN. THE GFS HINTS AT A
COASTAL TROUGH DEVELOPING WITH SHOWERS ALONG COASTAL AREAS AS EARLY
AS SATURDAY AFTERNOON. IF THIS PANS OUT COASTAL TERMINALS MAY SEE
ISOLATED SHOWERS LATE SATURDAY AND SUNDAY BEFORE A NEW AREA OF HIGH
PRESSURE BUILDS SOUTH OUT OF CANADA BY MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM THURSDAY...NE FLOW 15 TO 20 KT WILL CONTINUE TODAY AND
TONIGHT WITH AN INCREASE IN WINDS LATER THIS EVENING AS SFC HIGH
OVER NEW ENGLAND STRENGTHENS AND BUILDS DOWN THE COAST. SPEEDS WILL
APPROACH...AND MAY EXCEED...25 KT BY THE END OF THE PERIOD. SEAS
WILL CONTINUE RUNNING 3 TO 5 FT IN RESPONSE TO PERIOD OF EXTENDED NE
FLOW. INCREASE IN SPEEDS LATER TONIGHT WILL PUSH SEAS ACROSS NC
ZONES TO 6 FT BY THE END OF THE PERIOD.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...THE LATEST GFS SHOWS AN AREA OF STRONGER 925MB
WINDS ACROSS THE WATERS AT THE BEGINNING OF THE PERIOD...NEAR 30
KNOTS WHICH BASICALLY PERSISTS THROUGH SATURDAY AFTERNOON. THIS WILL
EQUATE TO 20-25 KNOTS AT THE SURFACE. SPEEDS STEP SLIGHTLY BY EARLY
SUNDAY MORNING CLOSER TO 20 KNOTS BUT WILL STILL ADVERTISE A RANGE
OF 20-25 KNOTS.
SEAS WILL BE FIRMLY IN SMALL CRAFT RANGES AT THE BEGINNING OF THE
PERIOD AND WILL CONTINUE THROUGH SUNDAY MORNING. BASED ON THIS AND
THE FACT THE MODELS HAVE BEEN VERY CONSISTENT IN ADVERTISING THIS
SCENARIO A FEW PERIODS NOW...WILL GO AHEAD AND HOIST SMALL CRAFT ADVISORY
ALL ZONES BEGINNING FRIDAY.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 AM THURSDAY...NE FLOW WILL PERSIST THROUGH MONDAY. SPEEDS
MAY RELAX JUST ENOUGH TO ALLOW SEAS TO DIP BELOW FLAG
CRITERIA...OTHERWISE NO CHANGES.
&&
.TIDES/COASTAL FLOODING...
SYNOPTIC SET UP WARRANTS A LOOK AT COASTAL FLOODING THREAT.
TIDES ARE RUNNING A BIT ABOVE NORMAL AT SPRINGMAID PIER AND OYSTER
LANDING...FEEL CONFIDENT THAT LEVELS WILL REMAIN BELOW THRESHOLDS
FOR COASTAL FLOOD ADVISORY AT THIS POINT. WILL CONTINUE TO MONITOR
CLOSELY HOWEVER.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT FRIDAY FOR AMZ250-
252-254-256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...III
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...III/EH
TIDES/COASTAL FLOODING...SHK/III
000
FXUS62 KRAH 180633
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
233 AM EDT THU SEP 18 2008
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL BEGIN TO EXTEND INTO THE AREA FROM THE
NORTH TODAY...BRINGING COOL AND DRY CONDITIONS TO CENTRAL NORTH
CAROLINA TODAY THROUGH SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 100 AM THURSDAY...
SFC ANALYSIS THIS MORNING SHOWED 1030 MB HIGH PRESSURE CENTERED JUST
NORTH OF THE UPPER GREAT LAKES. A SFC RIDGE AXIS EXTENDED S/SE
THROUGH THE OH VALLEY INTO THE MID-ATLANTIC. ACROSS CENTRAL NC...
DEWPOINTS RANGED FROM THE MID 50S TO LOWER 60S. ALOFT...00Z RAOB
ANALYSIS AND WV IMAGERY SHOWED THE UPPER TROUGH AXIS THAT HAS BEEN
TO OUR WEST FINALLY SHIFTING EAST ACROSS THE AREA.
TODAY:
1030 MB HIGH PRESSURE CURRENTLY JUST NORTH OF THE UPPER GREAT LAKES
IS PROGGED TO SHIFT EAST INTO NEW ENGLAND BY THIS EVENING...
STRENGTHENING THE PRESSURE GRADIENT ACROSS THE MID-ATLANTIC AND
CAROLINAS AS THE FAMILIAR INVERTED SFC RIDGE NOSES DOWN THE LEE OF
THE APPALACHIANS. WITH AN INCREASED DRY NNE LOW LEVEL FLOW...IN
ADDITION TO SUBSIDENCE ALOFT IN THE WAKE OF THE UPPER TROUGH
CURRENTLY PASSING THROUGH THE AREA...EXPECT DRY CONDITIONS TODAY...
WITH FCST SOUNDINGS SHOWING PWAT VALUES IN THE 0.50-0.75" RANGE.
ALTHOUGH SOME CLOUD COVER WILL BE AROUND DURING THE MORNING HOURS...
PRIMARILY IN THE EAST...WE SHOULD SEE CLEAR OR MOSTLY CLEAR SKIES BY
AFTERNOON. FCST SOUNDINGS ARE UNANIMOUS IN SHOWING 15-20 KNOTS
THROUGHOUT THE MIXED LAYER THIS AFTERNOON IN THE COASTAL PLAIN...
AROUND 15 KNOTS IN THE TRIANGLE...AND 10-15 KNOTS IN THE WESTERN
PIEDMONT. AS SUCH...WE SHOULD SEE SOMEWHAT BREEZY SUSTAINED NNE OR
NE WINDS IN THE 15-20 MPH RANGE IN THE COASTAL PLAIN...WITH LOWER
VALUES IN THE 10-15 MPH RANGE BY THE TIME YOU GET TO THE FAR WESTERN
PIEDMONT. A BLEND OF GFS/NAM THICKNESSES TODAY GIVES VALUES FROM
ROUGHLY 1375 METERS THIS MORNING TO 1385 METERS THIS AFTERNOON...
WHICH SUPPORTS HIGH TEMPS IN THE UPPER 70S TO NEAR 80F. MOS GUIDANCE
IS A FEW DEGREES WARMER. GIVEN 10-20 MPH NNE/NE FLOW THIS
AFTERNOON...FEEL THAT TEMPS SHOULD BE LOWER THAN MOS GUIDANCE AND
MORE IN LINE WITH WHAT THE THICKNESSES SUGGEST...AND WILL FCST HIGHS
RANGING FROM 78-81F.
TONIGHT:
LOW LEVEL NORTHEAST FLOW FURTHER INCREASES OVERNIGHT AS THE PRESSURE
GRADIENT CONTINUES TO TIGHTEN AS THE INVERTED SFC RIDGE BECOMES
FIRMLY ESTABLISHED ACROSS THE MID-ATLANTIC AND CAROLINAS. FCST
SOUNDINGS SHOW 30 KNOT FLOW AS LOW AS 1500-2000 FT AGL TONIGHT. WITH
OTHERWISE EXCELLENT RADIATIONAL COOLING CONDS...SHOULD SEE NE WINDS
NO MORE THAN ~10 KNOTS AS MIXING IS MITIGATED BY THE NOCTURNAL
INVERSION. FCST SOUNDINGS HINT AT THE POSSIBILITY OF LOW STRATUS
DEVELOPING IN THE STRONG NE LOW LEVEL FLOW BETWEEN 06-12Z FRIDAY
MORNING...AND WILL TRY TO ACCOUNT FOR THIS BY SHOWING PARTLY CLOUDY
SKIES BY SUNRISE...ALTHOUGH IT IS POSSIBLE SOME AREAS COULD BE
MOSTLY CLOUDY. THE POSSIBILITY OF LOW STRATUS AND THE 5-10 KNOT NE
WINDS SHOULD KEEP TEMPS FROM BOTTOMING OUT AS MUCH AS THEY WOULD
OTHERWISE (GIVEN THE AIRMASS IN PLACE)...AND WILL FCST LOWS IN THE
MID/UPPER 50S TO 60F. -VINCENT
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
AS OF 200 AM THURSDAY...
FRIDAY AND FRIDAY NIGHT:
THE PRIMARY FCST PROBLEM DURING THIS PERIOD WILL BE WITH HOW BREEZY
WE GET LATE FRIDAY MORNING INTO FRIDAY AFTERNOON. FCST SOUNDINGS
SHOW A TIGHT PRESSURE GRADIENT ACROSS CENTRAL NC...BETWEEN A 1035 MB
SFC HIGH OVER NORTHERN NEW ENGLAND (WITH VERY PRONOUNCED SFC RIDGING
EXTENDING SOUTH INTO THE CAROLINAS) AND A WEAK AREA OF LOW PRESSURE
OFF THE SOUTHEAST COAST. GFS/NAM FCST SOUNDINGS ARE VERY SIMILAR IN
SHOWING 20-25 KNOT NORTHEAST FLOW IN THE MIXED LAYER IN THE COASTAL
PLAIN LATE FRIDAY MORNING INTO FRIDAY AFTERNOON...WITH 15-20 KNOT NE
FLOW FURTHER WEST TOWARD THE WESTERN PIEDMONT. AS SUCH...WILL
FORECAST A SOMEWHAT BREEZY DAY...WITH 15-20 MPH SUSTAINED NORTHEAST
WINDS GUSTING UP TO 25-30 MPH IN THE COASTAL PLAIN...AND AROUND 15
MPH GUSTING UP TO 25 MPH ELSEWHERE. NOW...IF THERE IS EXTENSIVE LOW
STRATUS FRIDAY MORNING...THIS MAY CUT DOWN ON THE GUSTINESS DUE TO
DECREASED INSOLATION/MIXING AFTER SUNRISE...PARTICULARLY IF ANY
STRATUS HANGS AROUND INTO THE EARLY AFTERNOON. AT THIS TIME WILL
FCST PARTLY CLOUDY SKIES IN THE MORNING...BECOMING PARTLY CLOUDY TO
MOSTLY SUNNY IN THE AFTERNOON. WITH COLD ADVECTION...THICKNESSES
BARELY RISE AT ALL DURING THE DAY...AND LOCAL RESEARCH SUGGESTS HIGH
TEMPS WILL RANGE FROM THE LOWER TO MID 70S (73-77F). MAV/MET MOS
GUIDANCE LOOKS TOO WARM FOR THE SYNOPTIC PATTERN AND THICKNESSES...
AND THEREFORE I TRENDED MORE TOWARD THE COOLER MET GUIDANCE...
ALTHOUGH I AM A DEGREE OR TWO COOLER THAN THAT IN SOME CASES. CLEAR
SKIES AND A VERY COOL/DRY AIRMASS IN PLACE SHOULD PROMOTE LOW TEMPS
IN THE MID 50S...STILL NOT AS LOW AS THEY COULD DUE TO ~10 KT
NORTHEAST WINDS THROUGH THE NIGHT GIVEN A TIGHT PRESSURE GRADIENT.
LOWEST TEMPS IN N/NW (WHERE WINDS SHOULD BE LIGHTER) AND HIGHEST IN
THE S/SE.
SATURDAY THROUGH SUNDAY NIGHT:
SFC RIDGING IS EXPECTED TO CONTINUE EXTENDING INTO THE AREA FROM THE
NORTH THROUGH THE WEEKEND...ALTHOUGH THE PRESSURE GRADIENT WILL
WEAKEN QUITE A BIT AS THE SFC HIGH OVER NEW ENGLAND IS BUMPED
OFFSHORE EARLY SAT MORNING BY A DEEP UPPER LEVEL TROUGH MOVING EAST
THROUGH CANADA. BOTH THE GFS/NAM SHOW A WEAK SFC LOW OR BROAD SFC
TROUGH OFFSHORE THE SOUTHEAST AND SOUTHERN MID-ATLANTIC COAST ON
SAT/SUN...ALTHOUGH NEITHER BRING ANY ATLANTIC MOISTURE INTO THE AREA
ON SATURDAY GIVEN THE OFFSHORE LOCATION AND WEAK NATURE OF THE LOW
OR TROUGH. THE NAM TRIES TO STRENGTHEN THE TROUGH INTO A SFC LOW OFF
CAPE HATTERAS ON SUNDAY...WITH MOISTURE WRAPPING BACK INTO SOUTHEAST
VA AND PORTIONS OF CENTRAL NC (PRIMARILY NE COASTAL PLAIN)...
HOWEVER...THE GFS KEEPS THE SYSTEM AS A WEAK/BROAD SFC TROUGH OUT
OVER THE GULF STREAM...WITH ALL OF CENTRAL NC STAYING DRY. AT THIS
TIME PREFER TO KEEP THE FCST DRY ON BOTH SAT/SUN SINCE THE NAM
SOLUTION LOOKS SOMEWHAT ODD. HIGH TEMPS ON SAT IN THE MID/UPPER
70S...INCREASING TO THE UPPER 70S TO LOWER 80S ON SUNDAY AS
THICKNESSES BEGIN TO RECOVER. LOW TEMPS ON SUN/MON MORNINGS IN THE
MID/UPPER 50S TO LOWER 60S. -VINCENT
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 230 AM THURSDAY...
BOTH THE GFS/ECMWF SHOW A DEEP UPPER VORTEX MOVING THROUGH EASTERN
CANADA INTO THE ATLANTIC AT THE BEGINNING OF THE LONG TERM
PERIOD...WITH AN UPPER RIDGE ON ITS HEELS. THIS PROVIDES AN IDEAL
SETUP FOR MASS CONVERGENCE ALOFT...AND STRENGTHENING HIGH PRESSURE
AT THE SFC OVER NEW ENGLAND. WE COULD ACTUALLY SEE A SFC HIGH IN THE
1035-1040 MB RANGE IN NEW ENGLAND BY EARLY/MID WEEK...WITH A STRONG
SFC RIDGE AXIS EXTENDING SOUTH/SW INTO THE MID-ATLANTIC AND
CAROLINAS. BOTH MODELS ARE SHOWING WEAK LOW PRESSURE OR A SFC TROUGH
OFF THE EAST/SE COAST DURING THIS TIME...ALTHOUGH THEY HAVE BEEN
VARYING WITH THE POSITION/STRENGTH OF THE OFFSHORE SFC LOW OR TROUGH
FROM RUN-TO-RUN...LEADING TO SOME UNCERTAINTY WITH THE DETAILS OF
THE FCST. ALTHOUGH FCST SOUNDINGS ARE INITIALLY REASONABLY MOIST
WITH PWAT VALUES AROUND 1.00" ON MONDAY (INCREASED MID/UPPER LEVEL
MOISTURE)...THEY BEGIN TO DRY OUT THEREAFTER...DROPPING TO
0.50-0.75" FOR TUE/WED. THIS WILL OBVIOUSLY DEPEND ON THE POSITION
AND STRENGTH OF ANY OFFSHORE SFC LOW/TROUGH...THOUGH. BOTH THE
GFS/ECMWF SHOW A VERY TIGHT PRESSURE GRADIENT BY TUE/WED...WITH
DOWNRIGHT BREEZY/WINDY CONDITIONS WITH 25-35 KNOTS IN THE MIXED
LAYER. THIS FAR OUT IN THE FCST...WILL KEEP NORTHEAST WINDS IN THE
10-15 KNOT RANGE AT MOST...ALTHOUGH I WOULD NOT BE SURPRISED TO SEE
SUSTAINED WINDS CLOSE TO WIND ADVISORY CRITERIA IN THE EASTERN HALF
OF THE AREA IF THE GFS FCST SOUNDINGS VERIFY.
ALSO...AT THIS TIME...WILL KEEP THE FCST DRY THROUGH THE EXTENDED
PERIOD WITH SUCH A STRONG COOL/DRY SFC RIDGE AXIS EXTENDING INTO THE
AREA...AND ANY OFFSHORE SFC LOW OR TROUGH EXPECTED TO REMAIN FAR
ENOUGH OUT TO KEEP ANY WRAP-AROUND MOISTURE ALONG THE COAST OR
OFFSHORE. HIGH TEMPS SHOULD START OUT NEAR NORMAL ON MONDAY...
DROPPING TO BELOW NORMAL BY TUE/WED. SOME OF THE GFS FCST SOUNDINGS
SHOW HIGH TEMPS STRUGGLING TO GET OUT OF THE 60S ON TUE/WED...BUT AT
THIS TIME...WILL TREND TO JUST A FEW DEGREES BELOW NORMAL...WITH
HIGHS IN THE LOWER/MID 70S AND LOWS IN THE MID/UPPER 50S ON
TUE/WED/THU. -VINCENT
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 200 AM THURSDAY...
SKIES WILL CONTINUE TO CLEAR OVER THE EASTERN PORTION OF CENTRAL
NORTH CAROLINA AS AN UPPER LEVEL TROUGH WORKS ITS WAY EAST ACROSS
THE REGION. HOWEVER THE COMBINATION OF CLEAR SKIES... LIGHT WINDS
AND LIMITED TEMP/DEWPOINT SPREADS WILL LEAD TO THE DEVELOPMENT OF
MOSTLY MVFR VISIBILITIES IN FOG. THERE IS A CHANCE OF IFR CONDITIONS
AROUND RWI. THE FOG WILL DISSIPATE AFTER 12-13Z AS WINDS INCREASE
FROM THE NORTH AND NORTHEAST. VFR CONDITIONS SHOULD PERSIST WILL
TONIGHT.
AS HIGH PRESSURE BUILDS OVER THE REGION FRIDAY AND COOL NORTHEAST
WINDS INCREASE OVER THE AREA... THERE MAY BE A PERIOD OF MVFR
CEILINGS DURING THE MORNING INTO THE EARLY AFTERNOON. NORTHEAST
WINDS AT 15 KNOTS WILL GUST TO AROUND 25 KNOTS DURING THE AFTERNOON
FRIDAY... OTHERWISE WE CAN EXPECT VFR CONDITIONS THROUGH MONDAY. THE
EXCEPTION... THERE MAY BE AN INCREASE IN CLOUDS OVER THE EASTERN TAF
AREA SATURDAY NIGHT INTO MIDDAY SUNDAY IN RESPONSE TO AN INVERTED
TROUGH ALONG THE COAST. -RHJ
&&
.EQUIPMENT...
THERE WILL BE NO GSO UPPER AIR DATA THROUGH AT LEAST 12Z/18TH DUE TO
EQUIPMENT FAILURE.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...VINCENT
LONG TERM...VINCENT
AVIATION...RHJ
000
FXUS62 KRAH 180616
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
212 AM EDT THU SEP 18 2008
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL BEGIN TO EXTEND INTO THE AREA FROM THE
NORTH TODAY...BRINGING COOL AND DRY CONDITIONS TO CENTRAL NORTH
CAROLINA TODAY INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 100 AM THURSDAY...
SFC ANALYSIS THIS MORNING SHOWED 1030 MB HIGH PRESSURE CENTERED JUST
NORTH OF THE UPPER GREAT LAKES. A SFC RIDGE AXIS EXTENDED S/SE
THROUGH THE OH VALLEY INTO THE MID-ATLANTIC. ACROSS CENTRAL NC...
DEWPOINTS RANGED FROM THE MID 50S TO LOWER 60S. ALOFT...00Z RAOB
ANALYSIS AND WV IMAGERY SHOWED THE UPPER TROUGH AXIS THAT HAS BEEN
TO OUR WEST FINALLY SHIFTING EAST ACROSS THE AREA.
TODAY:
1030 MB HIGH PRESSURE CURRENTLY JUST NORTH OF THE UPPER GREAT LAKES
IS PROGGED TO SHIFT EAST INTO NEW ENGLAND BY THIS EVENING...
STRENGTHENING THE PRESSURE GRADIENT ACROSS THE MID-ATLANTIC AND
CAROLINAS AS THE FAMILIAR INVERTED SFC RIDGE NOSES DOWN THE LEE OF
THE APPALACHIANS. WITH AN INCREASED DRY NNE LOW LEVEL FLOW...IN
ADDITION TO SUBSIDENCE ALOFT IN THE WAKE OF THE UPPER TROUGH
CURRENTLY PASSING THROUGH THE AREA...EXPECT DRY CONDITIONS TODAY...
WITH FCST SOUNDINGS SHOWING PWAT VALUES IN THE 0.50-0.75" RANGE.
ALTHOUGH SOME CLOUD COVER WILL BE AROUND DURING THE MORNING HOURS...
PRIMARILY IN THE EAST...WE SHOULD SEE CLEAR OR MOSTLY CLEAR SKIES BY
AFTERNOON. FCST SOUNDINGS ARE UNANIMOUS IN SHOWING 15-20 KNOTS
THROUGHOUT THE MIXED LAYER THIS AFTERNOON IN THE COASTAL PLAIN...
AROUND 15 KNOTS IN THE TRIANGLE...AND 10-15 KNOTS IN THE WESTERN
PIEDMONT. AS SUCH...WE SHOULD SEE SOMEWHAT BREEZY SUSTAINED NNE OR
NE WINDS IN THE 15-20 MPH RANGE IN THE COASTAL PLAIN...WITH LOWER
VALUES IN THE 10-15 MPH RANGE BY THE TIME YOU GET TO THE FAR WESTERN
PIEDMONT. A BLEND OF GFS/NAM THICKNESSES TODAY GIVES VALUES FROM
ROUGHLY 1375 METERS THIS MORNING TO 1385 METERS THIS AFTERNOON...
WHICH SUPPORTS HIGH TEMPS IN THE UPPER 70S TO NEAR 80F. MOS GUIDANCE
IS A FEW DEGREES WARMER. GIVEN 10-20 MPH NNE/NE FLOW THIS
AFTERNOON...FEEL THAT TEMPS SHOULD BE LOWER THAN MOS GUIDANCE AND
MORE IN LINE WITH WHAT THE THICKNESSES SUGGEST...AND WILL FCST HIGHS
RANGING FROM 78-81F.
TONIGHT:
LOW LEVEL NORTHEAST FLOW FURTHER INCREASES OVERNIGHT AS THE PRESSURE
GRADIENT CONTINUES TO TIGHTEN AS THE INVERTED SFC RIDGE BECOMES
FIRMLY ESTABLISHED ACROSS THE MID-ATLANTIC AND CAROLINAS. FCST
SOUNDINGS SHOW 30 KNOT FLOW AS LOW AS 1500-2000 FT AGL TONIGHT. WITH
OTHERWISE EXCELLENT RADIATIONAL COOLING CONDS...SHOULD SEE NE WINDS
NO MORE THAN ~10 KNOTS AS MIXING IS MITIGATED BY THE NOCTURNAL
INVERSION. FCST SOUNDINGS HINT AT THE POSSIBILITY OF LOW STRATUS
DEVELOPING IN THE STRONG NE LOW LEVEL FLOW BETWEEN 06-12Z FRIDAY
MORNING...AND WILL TRY TO ACCOUNT FOR THIS BY SHOWING PARTLY CLOUDY
SKIES BY SUNRISE...ALTHOUGH IT IS POSSIBLE SOME AREAS COULD BE
MOSTLY CLOUDY. THE POSSIBILITY OF LOW STRATUS AND THE 5-10 KNOT NE
WINDS SHOULD KEEP TEMPS FROM BOTTOMING OUT AS MUCH AS THEY WOULD
OTHERWISE (GIVEN THE AIRMASS IN PLACE)...AND WILL FCST LOWS IN THE
MID/UPPER 50S TO 60F. -VINCENT
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
AS OF 200 AM THURSDAY...
FRIDAY AND FRIDAY NIGHT:
THE PRIMARY FCST PROBLEM DURING THIS PERIOD WILL BE WITH HOW BREEZY
WE GET LATE FRIDAY MORNING INTO FRIDAY AFTERNOON. FCST SOUNDINGS
SHOW A TIGHT PRESSURE GRADIENT ACROSS CENTRAL NC...BETWEEN A 1035 MB
SFC HIGH OVER NORTHERN NEW ENGLAND (WITH VERY PRONOUNCED SFC RIDGING
EXTENDING SOUTH INTO THE CAROLINAS) AND A WEAK AREA OF LOW PRESSURE
OFF THE SOUTHEAST COAST. GFS/NAM FCST SOUNDINGS ARE VERY SIMILAR IN
SHOWING 20-25 KNOT NORTHEAST FLOW IN THE MIXED LAYER IN THE COASTAL
PLAIN LATE FRIDAY MORNING INTO FRIDAY AFTERNOON...WITH 15-20 KNOT NE
FLOW FURTHER WEST TOWARD THE WESTERN PIEDMONT. AS SUCH...WILL
FORECAST A SOMEWHAT BREEZY DAY...WITH 15-20 MPH SUSTAINED NORTHEAST
WINDS GUSTING UP TO 25-30 MPH IN THE COASTAL PLAIN...AND AROUND 15
MPH GUSTING UP TO 25 MPH ELSEWHERE. NOW...IF THERE IS EXTENSIVE LOW
STRATUS FRIDAY MORNING...THIS MAY CUT DOWN ON THE GUSTINESS DUE TO
DECREASED INSOLATION/MIXING AFTER SUNRISE...PARTICULARLY IF ANY
STRATUS HANGS AROUND INTO THE EARLY AFTERNOON. AT THIS TIME WILL
FCST PARTLY CLOUDY SKIES IN THE MORNING...BECOMING PARTLY CLOUDY TO
MOSTLY SUNNY IN THE AFTERNOON. WITH COLD ADVECTION...THICKNESSES
BARELY RISE AT ALL DURING THE DAY...AND LOCAL RESEARCH SUGGESTS HIGH
TEMPS WILL RANGE FROM THE LOWER TO MID 70S (73-77F). MAV/MET MOS
GUIDANCE LOOKS TOO WARM FOR THE SYNOPTIC PATTERN AND THICKNESSES...
AND THEREFORE I TRENDED MORE TOWARD THE COOLER MET GUIDANCE...
ALTHOUGH I AM A DEGREE OR TWO COOLER THAN THAT IN SOME CASES. CLEAR
SKIES AND A VERY COOL/DRY AIRMASS IN PLACE SHOULD PROMOTE LOW TEMPS
IN THE MID 50S...STILL NOT AS LOW AS THEY COULD DUE TO ~10 KT
NORTHEAST WINDS THROUGH THE NIGHT GIVEN A TIGHT PRESSURE GRADIENT.
LOWEST TEMPS IN N/NW (WHERE WINDS SHOULD BE LIGHTER) AND HIGHEST IN
THE S/SE.
SATURDAY THROUGH SUNDAY NIGHT:
SFC RIDGING IS EXPECTED TO CONTINUE EXTENDING INTO THE AREA FROM THE
NORTH THROUGH THE WEEKEND...ALTHOUGH THE PRESSURE GRADIENT WILL
WEAKEN QUITE A BIT AS THE SFC HIGH OVER NEW ENGLAND IS BUMPED
OFFSHORE EARLY SAT MORNING BY A DEEP UPPER LEVEL TROUGH MOVING EAST
THROUGH CANADA. BOTH THE GFS/NAM SHOW A WEAK SFC LOW OR BROAD SFC
TROUGH OFFSHORE THE SOUTHEAST AND SOUTHERN MID-ATLANTIC COAST ON
SAT/SUN...ALTHOUGH NEITHER BRING ANY ATLANTIC MOISTURE INTO THE AREA
ON SATURDAY GIVEN THE OFFSHORE LOCATION AND WEAK NATURE OF THE LOW
OR TROUGH. THE NAM TRIES TO STRENGTHEN THE TROUGH INTO A SFC LOW OFF
CAPE HATTERAS ON SUNDAY...WITH MOISTURE WRAPPING BACK INTO SOUTHEAST
VA AND PORTIONS OF CENTRAL NC (PRIMARILY NE COASTAL PLAIN)...
HOWEVER...THE GFS KEEPS THE SYSTEM AS A WEAK/BROAD SFC TROUGH OUT
OVER THE GULF STREAM...WITH ALL OF CENTRAL NC STAYING DRY. AT THIS
TIME PREFER TO KEEP THE FCST DRY ON BOTH SAT/SUN SINCE THE NAM
SOLUTION LOOKS SOMEWHAT ODD. HIGH TEMPS ON SAT IN THE MID/UPPER
70S...INCREASING TO THE UPPER 70S TO LOWER 80S ON SUNDAY AS
THICKNESSES BEGIN TO RECOVER. LOW TEMPS ON SUN/MON MORNINGS IN THE
MID/UPPER 50S TO LOWER 60S. -VINCENT
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 215 PM WEDNESDAY...
A STRONG POLAR VORTEX SWINGING THROUGH NEW ENGLAND WILL BRING A
REINFORCEMENT LOW-LEVEL FEED OF COOL AND DRY AIR IN THE FORM OF A
DRY COLD FRONTAL PASSAGE LATE SUNDAY NIGHT INTO MONDAY AND ANOTHER
STRONG +1035 MB SURFACE HIGH NOSING DOWN THE MID-ATLANTIC THROUGH
MIDWEEK.
TEMPERATURES WILL REMAIN SEASONABLE THROUGH THE PERIOD...GRADUALLY
FALLING TO SLIGHTLY BELOW NORMAL BY EARLY NEXT WEEK.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 200 AM THURSDAY...
SKIES WILL CONTINUE TO CLEAR OVER THE EASTERN PORTION OF CENTRAL
NORTH CAROLINA AS AN UPPER LEVEL TROUGH WORKS ITS WAY EAST ACROSS
THE REGION. HOWEVER THE COMBINATION OF CLEAR SKIES... LIGHT WINDS
AND LIMITED TEMP/DEWPOINT SPREADS WILL LEAD TO THE DEVELOPMENT OF
MOSTLY MVFR VISIBILITIES IN FOG. THERE IS A CHANCE OF IFR CONDITIONS
AROUND RWI. THE FOG WILL DISSIPATE AFTER 12-13Z AS WINDS INCREASE
FROM THE NORTH AND NORTHEAST. VFR CONDITIONS SHOULD PERSIST WILL
TONIGHT.
AS HIGH PRESSURE BUILDS OVER THE REGION FRIDAY AND COOL NORTHEAST
WINDS INCREASE OVER THE AREA... THERE MAY BE A PERIOD OF MVFR
CEILINGS DURING THE MORNING INTO THE EARLY AFTERNOON. NORTHEAST
WINDS AT 15 KNOTS WILL GUST TO AROUND 25 KNOTS DURING THE AFTERNOON
FRIDAY... OTHERWISE WE CAN EXPECT VFR CONDITIONS THROUGH MONDAY. THE
EXCEPTION... THERE MAY BE AN INCREASE IN CLOUDS OVER THE EASTERN TAF
AREA SATURDAY NIGHT INTO MIDDAY SUNDAY IN RESPONSE TO AN INVERTED
TROUGH ALONG THE COAST.
&&
.EQUIPMENT...
THERE WILL BE NO GSO UPPER AIR DATA THROUGH AT LEAST 12Z/18TH...
DUE TO EQUIPMENT FAILURE.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...VINCENT
LONG TERM...CBL
AVIATION...RHJ
000
FXUS62 KRAH 180600
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
200 AM EDT THU SEP 18 2008
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL BEGIN TO EXTEND INTO THE AREA FROM THE
NORTH TODAY...BRINGING COOL AND DRY CONDITIONS TO CENTRAL NORTH
CAROLINA TODAY INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 100 AM THURSDAY...
SFC ANALYSIS THIS MORNING SHOWED 1030 MB HIGH PRESSURE CENTERED JUST
NORTH OF THE UPPER GREAT LAKES. A SFC RIDGE AXIS EXTENDED S/SE
THROUGH THE OH VALLEY INTO THE MID-ATLANTIC. ACROSS CENTRAL NC...
DEWPOINTS RANGED FROM THE MID 50S TO LOWER 60S. ALOFT...00Z RAOB
ANALYSIS AND WV IMAGERY SHOWED THE UPPER TROUGH AXIS THAT HAS BEEN
TO OUR WEST FINALLY SHIFTING EAST ACROSS THE AREA.
TODAY:
1030 MB HIGH PRESSURE CURRENTLY JUST NORTH OF THE UPPER GREAT LAKES
IS PROGGED TO SHIFT EAST INTO NEW ENGLAND BY THIS EVENING...
STRENGTHENING THE PRESSURE GRADIENT ACROSS THE MID-ATLANTIC AND
CAROLINAS AS THE FAMILIAR INVERTED SFC RIDGE NOSES DOWN THE LEE OF
THE APPALACHIANS. WITH AN INCREASED DRY NNE LOW LEVEL FLOW...IN
ADDITION TO SUBSIDENCE ALOFT IN THE WAKE OF THE UPPER TROUGH
CURRENTLY PASSING THROUGH THE AREA...EXPECT DRY CONDITIONS TODAY...
WITH FCST SOUNDINGS SHOWING PWAT VALUES IN THE 0.50-0.75" RANGE.
ALTHOUGH SOME CLOUD COVER WILL BE AROUND DURING THE MORNING HOURS...
PRIMARILY IN THE EAST...WE SHOULD SEE CLEAR OR MOSTLY CLEAR SKIES BY
AFTERNOON. FCST SOUNDINGS ARE UNANIMOUS IN SHOWING 15-20 KNOTS
THROUGHOUT THE MIXED LAYER THIS AFTERNOON IN THE COASTAL PLAIN...
AROUND 15 KNOTS IN THE TRIANGLE...AND 10-15 KNOTS IN THE WESTERN
PIEDMONT. AS SUCH...WE SHOULD SEE SOMEWHAT BREEZY SUSTAINED NNE OR
NE WINDS IN THE 15-20 MPH RANGE IN THE COASTAL PLAIN...WITH LOWER
VALUES IN THE 10-15 MPH RANGE BY THE TIME YOU GET TO THE FAR WESTERN
PIEDMONT. A BLEND OF GFS/NAM THICKNESSES TODAY GIVES VALUES FROM
ROUGHLY 1375 METERS THIS MORNING TO 1385 METERS THIS AFTERNOON...
WHICH SUPPORTS HIGH TEMPS IN THE UPPER 70S TO NEAR 80F. MOS GUIDANCE
IS A FEW DEGREES WARMER. GIVEN 10-20 MPH NNE/NE FLOW THIS
AFTERNOON...FEEL THAT TEMPS SHOULD BE LOWER THAN MOS GUIDANCE AND
MORE IN LINE WITH WHAT THE THICKNESSES SUGGEST...AND WILL FCST HIGHS
RANGING FROM 78-81F.
TONIGHT:
LOW LEVEL NORTHEAST FLOW FURTHER INCREASES OVERNIGHT AS THE PRESSURE
GRADIENT CONTINUES TO TIGHTEN AS THE INVERTED SFC RIDGE BECOMES
FIRMLY ESTABLISHED ACROSS THE MID-ATLANTIC AND CAROLINAS. FCST
SOUNDINGS SHOW 30 KNOT FLOW AS LOW AS 1500-2000 FT AGL TONIGHT. WITH
OTHERWISE EXCELLENT RADIATIONAL COOLING CONDS...SHOULD SEE NE WINDS
NO MORE THAN ~10 KNOTS AS MIXING IS MITIGATED BY THE NOCTURNAL
INVERSION. FCST SOUNDINGS HINT AT THE POSSIBILITY OF LOW STRATUS
DEVELOPING IN THE STRONG NE LOW LEVEL FLOW BETWEEN 06-12Z FRIDAY
MORNING...AND WILL TRY TO ACCOUNT FOR THIS BY SHOWING PARTLY CLOUDY
SKIES BY SUNRISE...ALTHOUGH IT IS POSSIBLE SOME AREAS COULD BE
MOSTLY CLOUDY. THE POSSIBILITY OF LOW STRATUS AND THE 5-10 KNOT NE
WINDS SHOULD KEEP TEMPS FROM BOTTOMING OUT AS MUCH AS THEY WOULD
OTHERWISE (GIVEN THE AIRMASS IN PLACE)...AND WILL FCST LOWS IN THE
MID/UPPER 50S TO 60F. -VINCENT
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
AS OF 200 AM THURSDAY...
FRIDAY AND FRIDAY NIGHT:
THE PRIMARY FCST PROBLEM DURING THIS PERIOD WILL BE WITH HOW BREEZY
WE GET LATE FRIDAY MORNING INTO FRIDAY AFTERNOON. FCST SOUNDINGS
SHOW A TIGHT PRESSURE GRADIENT ACROSS CENTRAL NC...BETWEEN A 1035 MB
SFC HIGH OVER NORTHERN NEW ENGLAND (WITH VERY PRONOUNCED SFC RIDGING
EXTENDING SOUTH INTO THE CAROLINAS) AND A WEAK AREA OF LOW PRESSURE
OFF THE SOUTHEAST COAST. GFS/NAM FCST SOUNDINGS ARE VERY SIMILAR IN
SHOWING 20-25 KNOT NORTHEAST FLOW IN THE MIXED LAYER IN THE COASTAL
PLAIN LATE FRIDAY MORNING INTO FRIDAY AFTERNOON...WITH 15-20 KNOT NE
FLOW FURTHER WEST TOWARD THE WESTERN PIEDMONT. AS SUCH...WILL
FORECAST A SOMEWHAT BREEZY DAY...WITH 15-20 MPH SUSTAINED NORTHEAST
WINDS GUSTING UP TO 25-30 MPH IN THE COASTAL PLAIN...AND AROUND 15
MPH GUSTING UP TO 25 MPH ELSEWHERE. NOW...IF THERE IS EXTENSIVE LOW
STRATUS FRIDAY MORNING...THIS MAY CUT DOWN ON THE GUSTINESS DUE TO
DECREASED INSOLATION/MIXING AFTER SUNRISE...PARTICULARLY IF ANY
STRATUS HANGS AROUND INTO THE EARLY AFTERNOON. AT THIS TIME WILL
FCST PARTLY CLOUDY SKIES IN THE MORNING...BECOMING PARTLY CLOUDY TO
MOSTLY SUNNY IN THE AFTERNOON. WITH COLD ADVECTION...THICKNESSES
BARELY RISE AT ALL DURING THE DAY...AND LOCAL RESEARCH SUGGESTS HIGH
TEMPS WILL RANGE FROM THE LOWER TO MID 70S (73-77F). MAV/MET MOS
GUIDANCE LOOKS TOO WARM FOR THE SYNOPTIC PATTERN AND THICKNESSES...
AND THEREFORE I TRENDED MORE TOWARD THE COOLER MET GUIDANCE...
ALTHOUGH I AM A DEGREE OR TWO COOLER THAN THAT IN SOME CASES. CLEAR
SKIES AND A VERY COOL/DRY AIRMASS IN PLACE SHOULD PROMOTE LOW TEMPS
IN THE MID 50S...STILL NOT AS LOW AS THEY COULD DUE TO ~10 KT
NORTHEAST WINDS THROUGH THE NIGHT GIVEN A TIGHT PRESSURE GRADIENT.
LOWEST TEMPS IN N/NW (WHERE WINDS SHOULD BE LIGHTER) AND HIGHEST IN
THE S/SE.
SATURDAY THROUGH SUNDAY NIGHT:
SFC RIDGING IS EXPECTED TO CONTINUE EXTENDING INTO THE AREA FROM THE
NORTH THROUGH THE WEEKEND...ALTHOUGH THE PRESSURE GRADIENT WILL
WEAKEN QUITE A BIT AS THE SFC HIGH OVER NEW ENGLAND IS BUMPED
OFFSHORE EARLY SAT MORNING BY A DEEP UPPER LEVEL TROUGH MOVING EAST
THROUGH CANADA. BOTH THE GFS/NAM SHOW A WEAK SFC LOW OR BROAD SFC
TROUGH OFFSHORE THE SOUTHEAST AND SOUTHERN MID-ATLANTIC COAST ON
SAT/SUN...ALTHOUGH NEITHER BRING ANY ATLANTIC MOISTURE INTO THE AREA
ON SATURDAY GIVEN THE OFFSHORE LOCATION AND WEAK NATURE OF THE LOW
OR TROUGH. THE NAM TRIES TO STRENGTHEN THE TROUGH INTO A SFC LOW OFF
CAPE HATTERAS ON SUNDAY...WITH MOISTURE WRAPPING BACK INTO SOUTHEAST
VA AND PORTIONS OF CENTRAL NC (PRIMARILY NE COASTAL PLAIN)...
HOWEVER...THE GFS KEEPS THE SYSTEM AS A WEAK/BROAD SFC TROUGH OUT
OVER THE GULF STREAM...WITH ALL OF CENTRAL NC STAYING DRY. AT THIS
TIME PREFER TO KEEP THE FCST DRY ON BOTH SAT/SUN SINCE THE NAM
SOLUTION LOOKS SOMEWHAT ODD. HIGH TEMPS ON SAT IN THE MID/UPPER
70S...INCREASING TO THE UPPER 70S TO LOWER 80S ON SUNDAY AS
THICKNESSES BEGIN TO RECOVER. LOW TEMPS ON SUN/MON MORNINGS IN THE
MID/UPPER 50S TO LOWER 60S. -VINCENT
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 215 PM WEDNESDAY...
A STRONG POLAR VORTEX SWINGING THROUGH NEW ENGLAND WILL BRING A
REINFORCEMENT LOW-LEVEL FEED OF COOL AND DRY AIR IN THE FORM OF A
DRY COLD FRONTAL PASSAGE LATE SUNDAY NIGHT INTO MONDAY AND ANOTHER
STRONG +1035 MB SURFACE HIGH NOSING DOWN THE MID-ATLANTIC THROUGH
MIDWEEK.
TEMPERATURES WILL REMAIN SEASONABLE THROUGH THE PERIOD...GRADUALLY
FALLING TO SLIGHTLY BELOW NORMAL BY EARLY NEXT WEEK.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AS OF 730 PM WEDNESDAY...
BROKEN TO OVERCAST SKIES WITH CLOUD DECKS BETWEEN 7000-9000 FEET
ARE GRADUALLY DISSIPATING TO A SCATTERED LAYER FROM WEST TO EAST.
DRY AIR MOVING IN FROM THE WEST IN THE MID LEVELS WILL HELP TO
SCOUR OUT WHAT IS LEFT OF THIS MID LEVEL DECK THROUGH MIDNIGHT
FROM RDU EAST. IN THE LOWER LEVELS THE 925-850MB FLOW IS COMING
OUT OF THE NE AND IS PUSHING SOME DRIER LOW LEVEL AIR INTO CENTRAL
AND EASTERN NC ACROSS RWI AND RDU. THIS LOW LEVEL DRIER AIR WILL
LIKELY LIMIT ANY FOG DEVELOPMENT ESPECIALLY AT RDU AND RWI. IT
WILL REMAIN TO BE SEEN IN THE DRIER AIR WILL MAKE IT TO FAY AND
SOME MVFR FOG MAY BE POSSIBLE AT FAY BY DAYBREAK. THERE WILL BE A
SLIGHTLY BETTER CHANCE FOR SOME 3SM MVFR FOG WEST OF RDU AT BOTH
GSO AND INT. MODELS SOUNDING PROFILES SUGGEST MORE AVAILABLE
MOISTURE IN THE NORTHWEST PIEDMONT AND A PERIOD OF MVFR FOG WITH A
FEW SCATTERED LOW CLOUDS ARE POSSIBLE AFTER 08Z. ANY MVFR FOG AND
CLOUDS WILL BURN OFF WITH SUNRISE THURSDAY. A FEW CLOUDS WILL
LIKELY REDEVELOP AROUND 5000-8000 FEET IN THE AFTERNOON BUT SHOULD
REMAIN FEW-SCT. NORTHEAST WINDS WILL INCREASE TO AROUND 8-10KT BY
15Z AS HEATING MIXES DOWN A LITTLE STRONGER WINDS IN THE NE FLOW.
FOR FRIDAY THROUGH SUNDAY....VFR CONDITIONS EXPECTED. THERE WILL
BE PERIODS OF CLOUDINESS BUT BASES SHOULD REMAIN ABOVE 3000FT.
EXCEPTION MAY BE FRIDAY MORNING AS SECONDARY SURGE OF COOLER AIR
OCCURS. THIS MAY RESULT IN A DECK OF STRATUS WITH BASES BETWEEN
2000-3000FT.
&&
.EQUIPMENT...
THERE WILL BE NO GSO UPPER AIR DATA THROUGH AT LEAST 12Z/18TH...
DUE TO EQUIPMENT FAILURE.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...VINCENT
LONG TERM...CBL
AVIATION...JO
000
FXUS62 KILM 180545
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
145 AM EDT THU SEP 18 2008
.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE CAROLINAS THROUGH THE WEEKEND
AND BRING COOLER THAN NORMAL TEMPERATURES TO THE REGION. A WEAK
COLD FRONT WILL APPROACH EARLY NEXT WEEK...FOLLOWED BY HIGH
PRESSURE THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 900 PM WEDNESDAY...ONLY RESIDUAL PATCHY LIGHT RAIN OR DRIZZLE
TO PERSIST FOR THE REMAINDER OF THIS EVENING...MAINLY CLOSER TO THE
COAST. THERE-AFTER...THE MID-LEVEL TROF AXIS TO SWING JUST OFF THE
CAROLINA COASTS AROUND SUNRISE THURSDAY. WEAK MID-LEVEL IMPULSE
INTERACTING WITH THE STATIONARY FRONT OFFSHORE FROM THE ILM
CWA...WILL RESULT IN A WEAK SFC LOW ACCELERATING NE ALONG THIS
STALLED BOUNDARY OVERNITE. WILL LIKELY OBSERVE AN EXTENDED PERIOD
OF CLOUDS ALONG THE IMMEDIATE COAST THRU 3 AM. BEST SEEN VIA MODEL
TIME HEIGHT SECTIONS FOR LOCATIONS ALONG THE COAST. INLAND PORTIONS
OF THE CWA WILL OBSERVE CLEARING SKIES AFTER MIDNIGHT AS DRIER AIR
FILTERS IN AT ALL LEVELS OF THE ATM. THIS SEEN AGAIN THRU
MODEL TIME HEIGHT SECTIONS. AS FOR MIN TEMPS...VARIOUS MODEL MOS
GUIDANCE CLUSTERED CLOSE TO ONE ANOTHER ACROSS THE ILM CWA. CURRENT
LOWS ALREADY DEPICT VALUES THAT LOOK ON TARGET AND C NO REASON TO
CHANGE. SFC BASED INVERSION WILL KEEP N TO NE WINDS 5 KT OR LESS
INLAND. ALONG THE BEACHES...PINCHED GRADIENT EXTENDING FROM THE SFC
LOW MOVING AWAY FROM THE AREA OVERNITE...WILL KEEP N TO NE WINDS
5 TO OCCASIONALLY 10 MPH THRUOUT THE NITE.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...500 MB TROUGH AXIS WILL BE OVERHEAD AT THE
BEGINNING OF THE PERIOD...AND SLOWLY SHIFT OFF THE COAST BY FRIDAY
AS THE MID-LEVEL TROUGH LIFTS TO THE NORTHEAST. A MUCH DRIER
AIRMASS WILL BE USHERED IN AS WINDS ABOVE 700 MB SHIFT TO THE
NORTHWEST...MINIMIZING THE CHANCE FOR SIGNIFICANT PRECIP. AT THE
SURFACE...HIGH PRESSURE WILL SLIDE EAST ACROSS THE NORTHEASTERN
STATES WITH AN EXTENSION SOUTHWARD ACROSS THE CAROLINAS.
PERSISTENT NORTHEAST FLOW IS EXPECTED TO KEEP TEMPERATURES A SOLID
CATEGORY BELOW CLIMATOLOGICAL NORMS.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 3 AM WEDNESDAY...NO SIGNIFICANT CHANGES TO THE EXTENDED THIS
MORNING AS THE FORECAST REMAINS VERY CONSISTENT WITH SURFACE HIGH
PRESSURE RIDGING IN FROM THE NORTHEAST BASICALLY THROUGHOUT. THIS
MAKES THE TEMPERATURE FORECAST VERY UNIFORM MUCH LIKE THE SHORT TERM
AND DID NOT MAKE ANY CHANGES IN THAT REGARD. THE CAVEAT TO THE
FORECAST REMAINS THE POSSIBILITY OF A COASTAL TROUGH DEVELOPING AND
MOVING INLAND FOR THE LATTER PART OF THE WEEKEND AND INTO EARLY NEXT
WEEK. MADE CHANGES TO REFLECT AN INCREASING CHANCE OF SHOWERS
SATURDAY THROUGH MONDAY ALONG COASTAL AREAS.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
SKIES WILL CONTINUE GRADUAL CLEARING FROM FROM WEST TO EAST
OVERNIGHT WITH WINDS REMAINING LIGHT AND FROM THE NE. MAY SEE SOME
BRIEF PATCHY BR OVERNIGHT BUT COMBINATION OF DRY AND WELL MIXED
BOUNDARY LAYER WILL KEEP OCCURRENCES SHORT LIVED.
TIGHT GRADIENT WILL RESULT IN BREEZY CONDITIONS TODAY. PINCHED
GRADIENT ALONG THE IMMEDIATE COAST WILL RESULT IN HIGH WINDS AND
GUSTS AT COASTAL SITES. GRADIENT RELAXES A BIT IN THE AFTN WITH
SPEEDS STARTING TO EASE UP. LEFTOVER MOISTURE BETWEEN 3K AND 5K
MAY RESULT IN A FEW FAIR WEATHER CU DURING PEAK DAYTIME HEATING.
OUTLOOK THROUGH MONDAY...VFR GENERALLY EXPECTED. HIGH PRESSURE
BUILDS EAST OF NOVA SCOTIA OVER THE WEEKEND. THE FLOW AROUND THIS
HIGH WILL KEEP A FETCH OF AIR OFF THE OCEAN. THE GFS HINTS AT A
COASTAL TROUGH DEVELOPING WITH SHOWERS ALONG COASTAL AREAS AS EARLY
AS SATURDAY AFTERNOON. IF THIS PANS OUT COASTAL TERMINALS MAY SEE
ISOLATED SHOWERS LATE SATURDAY AND SUNDAY BEFORE A NEW AREA OF HIGH
PRESSURE BUILDS SOUTH OUT OF CANADA BY MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 900 PM WEDNESDAY...WINDS OVER THE WATERS TO PICK UP AND/OR
BECOME GUSTY AS THE SFC LOW ACCELERATES NE AND PASSES OFFSHORE FROM
THE WATERS OVERNIGHT. EXPECT N WINDS 15 TO 20 KT WITH FEW GUSTS TO
25 KT. BY SUNRISE...WITH THE MID-LEVEL TROF ABOUT TO MOVE OFF THE
COAST OF THE CAROLINAS...SFC HIGH TO RIDGE DOWN FROM THE NORTH
CAUSING A SLITE VEERING IN WIND DIRECTION...BUT CONTINUING AT THE
SAME SPEEDS. OVERALL...SEAS WILL PRIMARILY BE THE SHORT PERIOD WIND
DRIVEN WAVE PHENOMENA. DUE TO A NORTHERLY FETCH...SEAS WILL ONLY
BUILD TO 4 FT AT ITS HIEST EARLY ON TONIGHT. WITH THE FETCH BECOMING
MORE NORTHEASTERLY TOWARD SUNRISE AND DURING THE DAY ON THURSDAY...
THIS WILL ALLOW SEAS TO INCREASE BY A FOOT OR SO. WILL CONTINUE TO
HAVE A RANGE OF SEAS ACROSS THE COASTAL WATERS DUE TO WIND
DIRECTIONS AND THE CONFIGURATION OF THE SHORELINE.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...NORTHEAST FLOW WILL PREVAIL THROUGH THE
PERIOD AS HIGH PRESSURE BUILDS ACROSS THE INLAND CAROLINAS. TREND
WILL BE FOR WIND SPEEDS TO INCREASE IN RESPONSE TO A STRENGTHENING
GRADIENT...AND SEAS WILL BUILD DUE TO THE PERSISTENT NE FETCH.
SMALL CRAFT ADVISORY CONDITIONS MAY BE REACHED BY THU NIGHT AND
ONCE THEY DEVELOP...WOULD BE EXPECTED TO CONTINUE INTO FRIDAY NIGHT.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 3 PM WEDNESDAY...STEADY NELY FLOW ACROSS THE COASTAL WATERS
THROUGH THE PERIOD WITH HIGH PRESSURE EXTENDING SOUTHWEST ALONG THE
APPALACHIANS AND A COASTAL TROUGH OFFSHORE. STEADY FLOW WILL KEEP
SEAS IN AT LEAST THE 3 TO 5 FT RANGE AND THERE IS THE ALSO THE GOOD
POTENTIAL FOR 6 FT PLUS SEAS THROUGHOUT THE EXTENDED...AT LEAST FOR
THE OUTER FRINGES OF THE WATERS. AN EXTENDED PERIOD OF SMALL CRAFT
ADVISORY CONDITIONS WILL THEREFORE BE POSSIBLE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...CRM
NEAR TERM...MBB
SHORT TERM...CRM
LONG TERM...REK
AVIATION...III/EH
000
FXUS62 KRAH 180507
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
107 AM EDT THU SEP 18 2008
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL BEGIN TO EXTEND INTO THE AREA FROM THE
NORTH TODAY...BRINGING COOL AND DRY CONDITIONS TO CENTRAL NORTH
CAROLINA TODAY INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 100 AM THURSDAY...
SFC ANALYSIS THIS MORNING SHOWED 1030 MB HIGH PRESSURE CENTERED JUST
NORTH OF THE UPPER GREAT LAKES. A SFC RIDGE AXIS EXTENDED S/SE
THROUGH THE OH VALLEY INTO THE MID-ATLANTIC. ACROSS CENTRAL NC...
DEWPOINTS RANGED FROM THE MID 50S TO LOWER 60S. ALOFT...00Z RAOB
ANALYSIS AND WV IMAGERY SHOWED THE UPPER TROUGH AXIS THAT HAS BEEN
TO OUR WEST FINALLY SHIFTING EAST ACROSS THE AREA.
TODAY:
1030 MB HIGH PRESSURE CURRENTLY JUST NORTH OF THE UPPER GREAT LAKES
IS PROGGED TO SHIFT EAST INTO NEW ENGLAND BY THIS EVENING...
STRENGTHENING THE PRESSURE GRADIENT ACROSS THE MID-ATLANTIC AND
CAROLINAS AS THE FAMILIAR INVERTED SFC RIDGE NOSES DOWN THE LEE OF
THE APPALACHIANS. WITH AN INCREASED DRY NNE LOW LEVEL FLOW...IN
ADDITION TO SUBSIDENCE ALOFT IN THE WAKE OF THE UPPER TROUGH
CURRENTLY PASSING THROUGH THE AREA...EXPECT DRY CONDITIONS TODAY...
WITH FCST SOUNDINGS SHOWING PWAT VALUES IN THE 0.50-0.75" RANGE.
ALTHOUGH SOME CLOUD COVER WILL BE AROUND DURING THE MORNING HOURS...
PRIMARILY IN THE EAST...WE SHOULD SEE CLEAR OR MOSTLY CLEAR SKIES BY
AFTERNOON. FCST SOUNDINGS ARE UNANIMOUS IN SHOWING 15-20 KNOTS
THROUGHOUT THE MIXED LAYER THIS AFTERNOON IN THE COASTAL PLAIN...
AROUND 15 KNOTS IN THE TRIANGLE...AND 10-15 KNOTS IN THE WESTERN
PIEDMONT. AS SUCH...WE SHOULD SEE SOMEWHAT BREEZY SUSTAINED NNE OR
NE WINDS IN THE 15-20 MPH RANGE IN THE COASTAL PLAIN...WITH LOWER
VALUES IN THE 10-15 MPH RANGE BY THE TIME YOU GET TO THE FAR WESTERN
PIEDMONT. A BLEND OF GFS/NAM THICKNESSES TODAY GIVES VALUES FROM
ROUGHLY 1375 METERS THIS MORNING TO 1385 METERS THIS AFTERNOON...
WHICH SUPPORTS HIGH TEMPS IN THE UPPER 70S TO NEAR 80F. MOS GUIDANCE
IS A FEW DEGREES WARMER. GIVEN 10-20 MPH NNE/NE FLOW THIS
AFTERNOON...FEEL THAT TEMPS SHOULD BE LOWER THAN MOS GUIDANCE AND
MORE IN LINE WITH WHAT THE THICKNESSES SUGGEST...AND WILL FCST HIGHS
RANGING FROM 78-81F.
TONIGHT:
LOW LEVEL NORTHEAST FLOW FURTHER INCREASES OVERNIGHT AS THE PRESSURE
GRADIENT CONTINUES TO TIGHTEN AS THE INVERTED SFC RIDGE BECOMES
FIRMLY ESTABLISHED ACROSS THE MID-ATLANTIC AND CAROLINAS. FCST
SOUNDINGS SHOW 30 KNOT FLOW AS LOW AS 1500-2000 FT AGL TONIGHT. WITH
OTHERWISE EXCELLENT RADIATIONAL COOLING CONDS...SHOULD SEE NE WINDS
NO MORE THAN ~10 KNOTS AS MIXING IS MITIGATED BY THE NOCTURNAL
INVERSION. FCST SOUNDINGS HINT AT THE POSSIBILITY OF LOW STRATUS
DEVELOPING IN THE STRONG NE LOW LEVEL FLOW BETWEEN 06-12Z FRIDAY
MORNING...AND WILL TRY TO ACCOUNT FOR THIS BY SHOWING PARTLY CLOUDY
SKIES BY SUNRISE...ALTHOUGH IT IS POSSIBLE SOME AREAS COULD BE
MOSTLY CLOUDY. THE POSSIBILITY OF LOW STRATUS AND THE 5-10 KNOT NE
WINDS SHOULD KEEP TEMPS FROM BOTTOMING OUT AS MUCH AS THEY WOULD
OTHERWISE (GIVEN THE AIRMASS IN PLACE)...AND WILL FCST LOWS IN THE
MID/UPPER 50S TO 60F. -VINCENT
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
AS OF 215 PM THURSDAY...
FRIDAY NIGHT LOOKS TO BE COOLEST NIGHT IN STORE...AS BETTER
DECOUPLING IS EXPECTED...ESPECIALLY IN THE WEST...WITH THICKNESSES
DOWN TO AROUND 1360 12Z SATURDAY. WOULD NOT BE SURPRISED TO SEE SOME
LOWER 50S ACROSS THE NORTH AND NORTHWEST...AWAY FROM URBAN AREAS.
FORECAST HIGHS WERE CONSTRUCTED FROM LOCAL DRY ADIABATIC THICKNESS
SCHEME...FAVORING HIGHS JUST A TAD BELOW MOS GUIDANCE. HIGHS IN THE
LOWER TO MID 70S ON FRIDAY...WITH MID TO UPPER 70S ON SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 215 PM WEDNESDAY...
A CONTINUATION OF TRANQUIL WEATHER IS EXPECTED THROUGH THE PERIOD.
THE MAIN BELT OF WESTERLIES WILL REMAIN ALONG THE US/CANADA
BORDER...WELL REMOVED FROM CENTRAL NC. EXPECT TO SEE AN INCREASE IN
MID AND UPPER LEVEL MOISTURE/CLOUDS BY SATURDAY EVENING AS SWLY
WINDS STRENGTHEN ALOFT...IN RESPONSE TO A NEARLY STATIONARY SUBTLE
S/W TROUGH OVER THE SOUTHERN PLAINS. HOWEVER...THERE REMAINS AN
ABSENCE OF DEEP MOISTURE TRANSPORT INTO THE AREA...KEEPING THE
FORECAST DRY.
A STRONG POLAR VORTEX SWINGING THROUGH NEW ENGLAND WILL BRING A
REINFORCEMENT LOW-LEVEL FEED OF COOL AND DRY AIR IN THE FORM OF A
DRY COLD FRONTAL PASSAGE LATE SUNDAY AND INTO MONDAY AND ANOTHER
STRONG +1035 MB SURFACE HIGH NOSING DOWN THE MID-ATLANTIC THROUGH
MIDWEEK.
TEMPERATURES WILL REMAIN SEASONABLE THROUGH THE PERIOD...GRADUALLY
FALLING TO SLIGHTLY BELOW NORMAL BY EARLY NEXT WEEK.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AS OF 730 PM WEDNESDAY...
BROKEN TO OVERCAST SKIES WITH CLOUD DECKS BETWEEN 7000-9000 FEET
ARE GRADUALLY DISSIPATING TO A SCATTERED LAYER FROM WEST TO EAST.
DRY AIR MOVING IN FROM THE WEST IN THE MID LEVELS WILL HELP TO
SCOUR OUT WHAT IS LEFT OF THIS MID LEVEL DECK THROUGH MIDNIGHT
FROM RDU EAST. IN THE LOWER LEVELS THE 925-850MB FLOW IS COMING
OUT OF THE NE AND IS PUSHING SOME DRIER LOW LEVEL AIR INTO CENTRAL
AND EASTERN NC ACROSS RWI AND RDU. THIS LOW LEVEL DRIER AIR WILL
LIKELY LIMIT ANY FOG DEVELOPMENT ESPECIALLY AT RDU AND RWI. IT
WILL REMAIN TO BE SEEN IN THE DRIER AIR WILL MAKE IT TO FAY AND
SOME MVFR FOG MAY BE POSSIBLE AT FAY BY DAYBREAK. THERE WILL BE A
SLIGHTLY BETTER CHANCE FOR SOME 3SM MVFR FOG WEST OF RDU AT BOTH
GSO AND INT. MODELS SOUNDING PROFILES SUGGEST MORE AVAILABLE
MOISTURE IN THE NORTHWEST PIEDMONT AND A PERIOD OF MVFR FOG WITH A
FEW SCATTERED LOW CLOUDS ARE POSSIBLE AFTER 08Z. ANY MVFR FOG AND
CLOUDS WILL BURN OFF WITH SUNRISE THURSDAY. A FEW CLOUDS WILL
LIKELY REDEVELOP AROUND 5000-8000 FEET IN THE AFTERNOON BUT SHOULD
REMAIN FEW-SCT. NORTHEAST WINDS WILL INCREASE TO AROUND 8-10KT BY
15Z AS HEATING MIXES DOWN A LITTLE STRONGER WINDS IN THE NE FLOW.
FOR FRIDAY THROUGH SUNDAY....VFR CONDITIONS EXPECTED. THERE WILL
BE PERIODS OF CLOUDINESS BUT BASES SHOULD REMAIN ABOVE 3000FT.
EXCEPTION MAY BE FRIDAY MORNING AS SECONDARY SURGE OF COOLER AIR
OCCURS. THIS MAY RESULT IN A DECK OF STRATUS WITH BASES BETWEEN
2000-3000FT.
&&
.EQUIPMENT...
THERE WILL BE NO GSO UPPER AIR DATA THROUGH AT LEAST 12Z/18TH...
DUE TO EQUIPMENT FAILURE.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...CBL
LONG TERM...CBL
AVIATION...JO
| 
