000
FXUS64 KJAN 201640 AAA
AFDJAN
AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE JACKSON MS
1040 AM CDT TUE JAN 20 2009
.DISCUSSION...THE FORECAST AREA REMAINS ON THE WESTERN PERIPHERY OF
A LARGE UPPER LEVEL TROUGH WHICH ENCOMPASSES MOST OF THE EASTERN
HALF OF THE UNITED STATES. AS FAIRLY POTENT SHORTWAVE EMBEDDED IN
THIS LONGWAVE TROUGH CONTINUES TO SWING SOUTHEASTWARD THROUGH THE
FORECAST AREA OVER THE NEXT FEW HOURS...LOOK FOR LOW CLOUDS TO
CONTINUE TO SPREAD FURTHER SOUTH ACROSS THE REGION.
THIS DISTURBANCE HAS RESULTED IN SOME SNOW FLURRIES AND POCKETS OF
LIGHT SNOW FALLING ACROSS NORTH MISSISSIPPI THIS MORNING. THIS
ACTIVITY IS SLOWLY SINKING SOUTH SOUTHEAST...BUT IS ALSO IN THE
PROCESS OF DISSIPATING WHILE DOING SO. THIS WILL CONTINUE TO BE THE
TREND OVER THE NEXT SEVERAL HOURS. WITH THAT SAID...I WOULDN`T BE
SURPRISED IF RESIDENTS ACROSS NORTHEAST MISSISSIPPI...MAINLY ALONG
AND NORTH OF A LINE FROM GRENADA TO DEKALB...DURING THE NEXT FEW
EXPERIENCED A PERIOD OR TWO OF SOME LIGHT SNOW FLURRIES AS THIS
ACTIVITY MOVES ACROSS THE AREA. NO ACCUMULATION IS EXPECTED.
AS STATED BY THE PREVIOUS FORECASTER...WINDS WILL AGAIN BE AN ISSUE
IN PLACES ACROSS THE FORECAST AREA TODAY...AS A RESULT OF DEEP
MIXING AND STRONG COLD AIR ADVECTION. WHILE WINDS TODAY DON`T LOOK
TO BE NEARLY AS STRONG AS THOSE OBSERVED YESTERDAY...CONDITIONS WILL
CERTAINLY BE BREEZY IN OPEN LOCATIONS SUCH AS THE DELTA REGION...
ALONG THE MISSISSIPPI RIVER...AND AROUND SOME OF THE LARGER LAKES
AND RESERVOIRS ACROSS THE AREA. A LAKE WIND ADVISORY HAS BEEN
HOISTED FOR THESE AREAS TODAY UNTIL 4 PM.
THE CURRENT FORECAST LOOKS TO BE IN GOOD SHAPE FOR TODAY. I DID
ADJUST SKY COVERAGE A BIT TO ACCOUNT FOR CURRENT SATELLITE TRENDS AS
WELL AS SOME MINOR TWEAKS HOURLY TEMPERATURES BASED ON CURRENT
TRENDS. OTHER THAN THIS...NO MAJOR CHANGES WILL BE MADE TO THE
FORECAST AT THIS TIME. /19/
&&
.AVIATION...EVEN THOUGH CLEAR SKIES PREVAIL THIS MORNING...CLOUDS
ARE MOVING IN FROM THE NORTH/NORTHWEST. THESE CLOUDS SHOULD REMAIN
MAINLY IN THE 4-5KFT RANGE. THESE CLOUDS SHOULD LINGER THROUGH MOST
OF THE DAY AND THEN SHIFT EAST. THE MAIN CONCERN FOR THIS TAF PERIOD
IS THE WINDS. THEY SHOULD REMAIN OUT OF THE NORTH AROUND 10-15KTS
AND HIGHER GUSTS POSSIBLE. ALL IN ALL...VFR CONDITIONS EXPECTED
THROUGH THE NEXT 24 HOURS. /28/
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...LAKE WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR MSZ018-019-
025-026-031-034-035-040>043-047>049-052.
LA...LAKE WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR LAZ007>009-
015-016-023>026.
AR...LAKE WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR ARZ075.
&&
$$
19/28
000
FXUS64 KJAN 200931
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
330 AM CST TUE JAN 20 2009
...COLD TEMPERATURES FOR TODAY AND TONIGHT...
.SHORT TERM...THE FOCUS FOR THE NEXT 48 HRS WILL CONTINUE TO BE ON
THE COLD TEMPS THROUGH WED NIGHT...ESPECIALLY READINGS FOR TODAY AND
TONIGHT. THE MAIN WEATHER FEATURE CONTINUES TO BE THE LARGE E CONUS
TROUGH ALONG WITH EMBEDDED POTENT S/W WHICH HAVE BEEN ROTATING
THROUGH THE MEAN TROUGH. THE AREA SAW ONE MOVE BY YESTERDAY WHICH
PUSHED A FRONT THROUGH AND BROUGHT BREEZY/WINDY CONDITIONS. THE NEXT
ONE IS MOVING ACROSS NE AR AND WILL QUICKLY SPREAD ACROSS THE N HALF
OF MS BETWEEN 11-16Z. LOW CLOUDS HAVE BEEN SLOW TO SPREAD S
OVERNIGHT AND THAT HAS ALLOWED FOR MUCH BETTER COOLING CONDITIONS
AND AREA TEMPS HAVE BOTTOMED OUT BETWEEN 23-27 DEGREES.
HOWEVER...THE LEADING EDGE OF THE 4-5KFT DECK IS ACROSS THE N 1/3 OF
THE CWA AS OF 09Z AND LOOK FOR THIS DECK TO COVER ALL BUT THE SW 1/4
OF THE CWA FOR MOST OF THE DAY PERIOD. STRONG CAA WILL CONTINUE AND
HELP TO KEEP THESE CLOUDS AROUND ALONG WITH LIFT FROM THE S/W. THE
S/W AND TROUGH AXIS WILL SHIFT E OF THE AREA BY LATE AFTERNOON AND
THAT HELP SHIFT THE LOW LEVEL THERMAL AXIS E AS WELL AND ALLOW FOR
THE CLOUDS TO ERODE AND SHIFT E BETWEEN 21-02Z. THE ABV COMBINATIONS
SHOULD HELP TO KEEP TEMPS TODAY WELL BELOW CLIMO NORMS. LOOK FOR
UPPER 30S TO MID 40S WITH THE COLDEST AREAS ACROSS THE NE HALF.
DEPENDING ON HOW THICK/LONG THE CLOUDS ARE...TEMPS MAY BE A LITTLE
COOLER THAN WHAT I HAVE FORECAST.
AS FOR ANY SNOW FLURRY POTENTIAL...THERE STILL EXISTS THE POTENTIAL
AND I WILL CONTINUE TO CARRY FLURRIES FOR AREAS ALONG AND NE OF A
GREENWOOD TO MERIDIAN LINE. THE LIMITED LOW LEVEL MOISTURE WILL GET
SQUEEZED QUITE A BIT AS THE POTENT S/W MOVES OVER THE AREA THIS
MORNING AND THAT CAN SUPPORT THOSE FLURRIES. WILL CARRY THAT WORDING
UNTIL 10 AM.
THE OTHER WX ELEMENT OF INTEREST WILL BE WINDS AGAIN. MIXING WILL
AGAIN BE RATHER DEEP FOR THIS TIME OF YR AND WITH STRONG CAA IN
PLACE...WINDS WILL LIKELY OVER ACHIEVE. WIND SPEEDS DO NOT LOOK
NEARLY AS STRONG AS YESTERDAY SO I WILL HOLD OFF ON GOING WITH A
AREAWIDE LAKE WIND ADV. I WILL COVER AREAS ALONG THE MS RIVER AND
THE FLAT DELTA LAND WHERE WINDS TYPICALLY ARE STRONGER.
ADDITIONALLY...I WILL COVER THE COUNTIES WHERE LARGE BODIES OF WATER
EXIST. THE WARM WATER WILL ALLOW FOR SLIGHTLY DEEPER MIXING...THUS
STRONGER WINDS.
TONIGHT WILL BE COLD! CLR SKIES AND CALM WINDS WILL ALLOW FOR GREAT
RAD COOLING CONDITIONS AND TEMPS DROP OFF QUICKLY INTO THE 20S AND
BOTTOM OUT BETWEEN 19-23 DEGREES. LOOK FOR DECENT FROST AS WELL AS
SFC DEWPTS WILL RANGE FROM THE LOWER/MID 20S THIS AFTERNOON/EVENING
WHICH WILL SUPPORT SOME CROSSOVER POTENTIAL. LOOK FOR PATCHY LIGHT
FOG AS WELL NEAR ANY BODY OF WATER.
WED-WED NIGHT...CLR SKIES WILL PREVAIL AS WE BEGIN TO TRANSITION THE
WX PATTERN. HIGHS WILL LIKELY REMAIN BELOW NORMS AND RANGE FROM THE
LOWER TO MID 50S. AFTER SUCH A COLD START TO THE DAY...EXPECT A
RANGE AROUND 30 DEGREES. THE SFC RIDGE WILL SHIFT E/SE BUT THERE
WILL STILL BE THE LINGERING RIDGE AXIS HOLDING ON. DRY AIR AND COLD
GROUND CONDITIONS WILL ALLOW FOR ANOTHER COOL NIGHT WITH LOWS FROM
THE UPPER 20S(EAST) TO MID 30S(WEST).
AS A SIDE NOTE...WE STILL SEEM TO BE HAVING ISSUED WITH TEMPS AT
HBG. THIS WILL BE LOOKED INTO TODAY. /CME/
.LONG TERM...THURSDAY THROUGH TUESDAY...UPPER AIR PATTERN WILL
TRANSITION TO A PROGRESSIVE ZONAL PATTERN THEN TO A WETTER SOUTHWEST
PATTERN. MEDIUM RANGE AND ENSEMBLE MODELS SEEM TO BE IN GENERALLY
AGREEMENT. THERE SEEMS TO BE SOME PROGRESSION TOWARD THE COOLER
EUROPEAN SOLUTION WITH THIS WEEKENDS SYSTEM AND GOING INTO EARLY
NEXT WEEK. SOME QUESTIONS STILL REMAIN ON HOW MUCH COLD AIR WILL
COME WITH THIS SYSTEM FOR THIS WEEKEND AND IF IT WILL HAVE AFFECT ON
THE SHOWERS/RAIN. CONFIDENCE HAS IMPROVED SOME FOR THIS WEEKEND FOR
THIS MODEL RUN.
FOR THURSDAY WE WILL START TO GET SOME RETURN FLOW OVER THE REGION.
925 TEMPS WILL RISE TO AROUND 8-12C. WE WILL START TO GET SOME FLAT
UPPER RIDGING ACROSS THE REGION. WENT WITH MAV ON HIGHS FROM 60
NORTH TO THE UPPER 60S SOUTH. FOR THURSDAY NIGHT WENT CLOSE
TO MEX GUIDANCE WITH LOWS FROM THE LOWER 40S EAST TO THE LOWER
50S SOUTHWEST.
FOR FRIDAY INTO SATURDAY WE START GETTING INTO A LITTLE BETTER
CONSISTENCY WITH THE MODELS IN THE TIMING OF THE COLD FRONT AND IT
MOVING SOUTH OF THE REGION. THE EUROPEAN...GFS...AND ENSEMBLES
MOVE THE FRONT THROUGH THE REGION FRIDAY NIGHT INTO EARLY SATURDAY
...THEN MOVE IT SOUTH OF THE ARKLAMISS BY SATURDAY AFTERNOON.
MODELS SEEM TO SIMILAR ON THE DEPTH OF THE COLD AIR BEHIND THE FRONT.
AT THIS TIME DO NOT THINK THAT THERE WILL EB ENOUGH COLD AIR TO
CHANGE OVER THE SHOWERS TO LIGHT WINTER PRECIP. INSTABILITY WITH
THIS SYSTEM WILL BE QUITE STABLE. SO WILL KEEP IT ALL SHOWERS/RAIN.
THIS SYSTEM WILL STILL BEAR WATCHING AS MORE COLD WITH IT GETS IN
THE MODELS. FOR TEMPS WENT WITH THE GMOS WITH HIGHS FROM THE UPPER
50S NORTHWEST TO THE UPPER 60S SOUTHEAST FOR FRIDAY. FOR FRIDAY
NIGHT WENT CLOSER TO THE COOLER GMOS SOLUTION WITH LOWS FROM THE
MIDDLE 30S NORTH TO THE MIDDLE 40S SOUTHEAST. ON SATURDAY
WENT WITH MEX GUIDANCE WITH HIGHS FROM THE LOWER 40S NORTHWEST TO
THE UPPER 50S SOUTHEAST. LOWS FOR SATURDAY NIGHT WILL RANGE FROM THE
UPPER 20S NORTH TO MIDDLE 30S SOUTH. WENT CLOSER TO THE GMOS
GUIDANCE.
FOR SUNDAY...THE MODELS DRIES THINGS OUT AND CONTINUES TO BRING
A COLD AIRMASS INTO THE REGION. THIS OCCURS AS A 1030 PLUS HIGH
MOVES FROM THE OHIO VALLEY TO THE EASTERN SEABOARD. FOR TEMPS HIGHS
WILL RANGE FROM NEAR 50 NORTHWEST TO THE UPPER 50S SOUTH. THIS WAS
CLOSER TO THE COOLER GMOS MODEL GUIDANCE. LOWS FOR SUNDAY NIGHT WILL
RANGE FROM THE UPPER 30S NORTH TO THE MIDDLE 40S SOUTH. WENT CLOSE
TO MEX NUMBERS. WE WILL GET SOME RETURN MOISTURE ON SUNDAY NIGHT FOR
SOME SHOWERS.
FOR MONDAY...OUR CHANCES OF RAIN CONTINUE AS WE GET SOME WARM RETURN
FLOW AHEAD OF THE NEXT SYSTEM COMING OUT OF THE SOUTHERN PLAINS.
HIGHS WILL RANGE FROM THE UPPER 50S NORTH TO THE UPPER 60S SOUTH.
FOR MONDAY NIGHT INTO TUESDAY. THE NEXT SYSTEM WITH AN ASSOCIATED
COLD FRONT WILL CROSS THE AREA. ONCE AGAIN INSTABILITY WILL BE QUITE
LOW FOR ONLY SHOWERS. FOR MONDAY NIGHT LOWS WILL RANGE FROM THE
LOWER 40S NORTH TO THE MIDDLE 40S SOUTH...WHICH IS CLOSE TO MEX
GUIDANCE. HIGHS ON TUESDAY WILL BE FROM THE UPPER 40S NORTHWEST
TO THE MIDDLE 60S SOUTHEAST.
AS FAR AS POPS ARE CONCERN MADE SOME SLIGHT CHANGES TO MEX POPS FROM
FRIDAY THROUGH TUESDAY./17/
&&
.AVIATION...CLOUDS WILL EFFECT NEARLY ALL OF THE CWA TODAY BUT
REMAIN AROUND 4-5KFT. THESE SHOULD SHIFT E AND DISSIPATE BETWEEN
21-02Z. SFC WINDS ARE THE OTHER FOCUS AS THE AREA SHOULD SEE NW
WINDS AROUND 13-15KTS WITH GUSTS AROUND 20KTS.
VFR CONDITIONS WILL PREVAIL FOR THE 24-48 HR TIMEFRAME WITH CLR
SKIES AND LIGHT/CALM WINDS. /CME/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 40 22 53 31 / 0 0 0 0
MERIDIAN 39 19 51 27 / 2 0 0 0
VICKSBURG 42 23 54 34 / 0 0 0 0
HATTIESBURG 45 20 52 28 / 0 0 0 0
NATCHEZ 43 22 54 35 / 0 0 0 0
GREENVILLE 39 23 52 34 / 0 0 0 0
GREENWOOD 38 21 51 31 / 2 0 0 0
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...LAKE WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR MSZ018-019-
025-026-031-034-035-040>043-047>049-052.
LA...LAKE WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR LAZ007>009-
015-016-023>026.
AR...LAKE WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR ARZ075.
&&
$$
CME
17
000
FXUS64 KJAN 200409 AAB
AFDJAN
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON MS
1009 PM CST MON JAN 19 2009
.UPDATE...UPSTREAM SHORTWAVE TROUGH DROPPING INTO THE OZARKS BRINGING
A SOLID DECK OF CLOUDS 4-5K FEET AND POSSIBLE FLURRIES AS IT HEADS
SEWD AT 35KTS OR SO. EXPECT THESE CLOUDS TO REACH OUR DELTA REGION
BETWEEN 08-10Z AND THEN EXPAND AFTER DAYBREAK TO COVER MUCH OF CWFA.
LOW TEMPS HAVE BEEN ADJUSTED DOWNWARD A COUPLE OF DEGREES ALONG WITH
THE DEWPOINTS DUE TO THE LONGER CLEARING AND LIGHT WIND REGIME. LOOK
FOR READINGS TO RISE SLIGHTLY WHEN THE CLOUDS INCREASE FROM THE NW.
OTHERWISE...LITTLE CHANGE TO FORECAST PACKAGE AND UPDATES SHOULD
ALREADY BE AVAILABLE./40/
&&
.AVIATION...VFR CLEAR WILL PREVAIL AT ALL TAF SITES UNTIL AROUND 09Z
WHEN UPSTREAM CLOUD DECK OF 4-5K FEET SPREADS SEWD ACROSS THE REGION.
BREEZY NNW SURFACE WINDS HAVE SUBSIDED THROUGH THE EVENING HOURS TO
AROUND 6 KNOTS. AS A STRONG UPPER LEVEL TROUGH SWINGS ACROSS THE
REGION LATE TONIGHT INTO TUESDAY...THOSE CLOUDS DEVELOP AT LEAST
OVER NORTH CENTRAL AND NORTHEAST MISSISSIPPI 09-14Z LEADING TO SOME
SNOW FLURRIES. THE CLOUDS SHOULD EXPAND AFTER DAYBREAK TO MOST TAF
LOCATIONS BUT THEN START TO ERODE FROM SW TO NE AFTER 22Z./40/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 28 40 24 53 / 3 1 0 0
MERIDIAN 27 39 20 51 / 3 6 0 0
VICKSBURG 29 42 25 54 / 3 0 0 0
HATTIESBURG 30 45 21 51 / 3 2 0 0
NATCHEZ 29 44 24 54 / 3 0 0 0
GREENVILLE 25 40 26 53 / 5 0 0 0
GREENWOOD 25 38 23 51 / 7 3 0 0
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
000
FXUS64 KJAN 200016 AAA
AFDJAN
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON MS
616 PM CST MON JAN 19 2009
.UPDATE...RELAXING PRESSURE GRADIENT AND DECOUPLING BOUNDARY LAYER
WINDS RESULTING IN ABOUT 10-15KTS FOR MOST LOCATIONS THE REST OF
THE EVENING HOURS AND EVEN LIGHTER AFTER MIDNIGHT. HAVE REMOVED
THE LAKE WIND ADVSY AND ADJUSTED CLOUD COVER TO MATCH CURRENT TRENDS
MORE CLOSELY. LITTLE CHANGE OTHERWISE AS NEW LOAD OF DRY COLD AIR
SURGING INTO THE REGION ONCE AGAIN. REST OF FORECAST UNCHANGED FOR
NOW AND WILL BE REVIEWED LATER ON. UPDATES ALREADY SENT./40/
PREVIOUS DISCUSSION FOLLOWS:FORECAST TRENDS HAVE NOT CHANGED MUCH
THIS RUN AND LITTLE FORECAST ADJUSTMENTS HAVE BEEN NECESSARY. A
RELATIVELY DEEP UPPER TROUGH REMAINS ON TRACK TO DROP INTO THE
FORECAST AREA TONIGHT...INCREASING COLD AIR ADVECTION OVER AN ALREADY
CHILLY AIR MASS CURRENTLY IN PLACE. NRN/NERN ZONES WILL BE ON THE WRN
FRINGES OF THE BEST MOISTURE AND THE POSSIBILITY OF A FEW FLURRIES
WILL CONTINUE FOR THOSE AREAS LATE TONIGHT INTO EARLY TUESDAY MORNING
WITH NO ACCUMULATION EXPECTED. COLD AIR ADVECTION AND A PERSISTENT
DECK OF MOISTURE AROUND 850 MB WILL SET US UP FOR A COLD DAY
TOMORROW. THE ONLY SIGNIFICANT ADJUSTMENTS MADE TO THE FORECAST
INVOLVE TEMPERATURES WED AND WED NIGHT WHEN THE SLIGHTLY COOLER MOS
WAS PREFERRED OVER THE PREVIOUS FORECAST./03/
PREVIOUSLY...A 2ND MORE POTENT S/W...WILL HELP TO INCREASE THE LOW
LEVEL CAA AND THE CWA WILL SEE NEG H925 AND H85 TEMPS. ACTUALLY H925
WILL RUN BETWEEN -4 AND -7C WITH H85 BETWEEN -6 AND -12C. THESE VERY
COLD H85 TEMPS ARE AROUND NEG 3 STANDARD DEV BELOW CLIMO VALUES AND
SUPPORTS A LARGE DEPARTURE FROM NORMAL TEMPS. WITH THIS...I HAVE
LOWERED HIGHS TUE 1-3 DEGREES WITH A RANGE FROM THE MID 30S TO MID
40S. THERE WILL ALSO BE A DECENT STRATUS DECK FOR MOST OF THE DAY AND
40S COULD BE TOUGH TO REACH.
TUE NIGHT...WE WILL SEE A SFC HIGH SETTLE OVER THE CWA. SKIES WILL
QUICKLY CLR AND WINDS WILL GO CALM. TEMPS WILL DROP QUICKLY INTO THE
MID/UPPER 20S AREA WIDE AND ON THEIR WAY TO LOWS BETWEEN 20-25
DEGREES. SOME UPPER TEENS ARE NOT OUT OF THE QUESTION. LOOK FOR A
HEAVY FROST AS WELL AS DEWPTS WILL BE IN THE MID 20S DURING THE
AFTERNOON AND WITH SOME CROSSOVER TEMPS LIKELY FROST MAY BE ON THE
THICK SIDE. THERE MAY ALSO BE SOME FREEZING FOG NEAR THE RIVERS AND
LARGE BODIES OF WATER. /CME/
WEDNESDAY THROUGH MONDAY...UPPER AIR PATTERN WILL TRANSITION FROM A
COOL PATTERN TO A WARMER PATTERN THEN BACK TO A COOLER PATTERN FOR
THE WEEKEND DURING THE PERIOD. MEDIUM RANGE AND ENSEMBLE MODELS SEEM
TO BE IN GENERALLY AGREEMENT. THERE SEEM TO BE SOME QUESTION ON THIS
WEEKENDS SYSTEM COMING(ASSOCIATED COLD FRONT TIMING AND RAIN POPS)
INTO THE REGION FOR THE LAST OF THE PERIOD. CONFIDENCE IS NOT HIGH
FOR THE FRIDAY INTO MONDAY OF THIS PERIOD...DUE TO MODEL DIFFERENCES.
STARTING WITH WEDNESDAY IT WILL BE THE BEGINNING OF A TRANSITION
PERIOD WHERE THE AXIS OF THE UPPER TROUGH MOVES TO THE EASTERN
SEABOARD. 925 TEMPS WILL GRADUALLY WARM ON WEDNESDAY INTO THURSDAY.
FOR TEMPS WENT CLOSE TO GMOS GUIDANCE AS NAM LOOKED TO BE TOO COOL
DURING THE TRANSITION. HIGHS WILL BE FROM THE LOWER TO UPPER 50S.
FOR WEDNESDAY NIGHT KEPT WITH THE CURRENT LOWS FROM THE UPPER 20S
EAST TO THE MIDDLE 30S WEST.
FOR THURSDAY WE WILL START TO GET SOME RETURN FLOW OVER THE REGION.
925 TEMPS WILL RISE TO AROUND 10-13C. WE WILL START TO GET SOME FLAT
UPPER RIDGING ACROSS THE REGION. WENT WITH GMOS ON HIGHS FROM THE
UPPER 50S NORTHWEST TO THE UPPER 60S SOUTHEAST. FOR THURSDAY NIGHT
WENT CLOSE TO MEX GUIDANCE WITH LOWS FROM THE LOWER 40S NORTHEAST TO
THE LOWER 50S SOUTHWEST.
FOR FRIDAY INTO SATURDAY WE START GETTING SOME TIMING QUESTIONS WITH
A PASSAGE OF A COLD FRONT WITH AN ASSOCIATED SHORT WAVE.
THE EUROPEAN...GFS...AND ENSEMBLES HAVE SOME TIMING ISSUES OF A
FRONT THAT SEEMS TO HANG ACROSS THE SOUTH ON FRIDAY INTO SATURDAY.
THE EUROPEAN SEEMS TO BE THE MOST AGGRESSIVE IN PUSHING THE FRONT
AWAY FROM THE REGION BY SUNDAY MORNING...WHILE THE GFS AND ENSEMBLE
WITH THE BOUNDARY AROUND THE SOUTHERN PORTION OF THE REGION. WITH
THE 12Z EUROPEAN SOLUTION THERE MAY BE SOME WINTER PRECIP WITH THIS
SYSTEM ON SATURDAY IN THE NORTHWEST DELTA...BUT THE LATEST 00Z
SOLUTION DID NOT HAVE THE ICE...BUT WAS STILL COOL. WHILE THE OTHER
MODELS JUST HAD COLD SHOWERS. THIS SYSTEM WILL BEAR WATCHING AS MORE
COLD WITH IT GETS IN THE MODELS. FOR TEMPS WENT WITH THE GMOS WITH
HIGHS FROM THE UPPER 50S NORTHWEST TO THE UPPER 60S SOUTHEAST FOR
FRIDAY. FOR FRIDAY NIGHT WENT CLOSER TO THE COOLER EUROPEAN SOLUTION
WITH LOWS FROM THE UPPER 30S NORTHWEST TO THE MIDDLE 40S SOUTHEAST.
ON SATURDAY GFS TEMPS WERE TOO WARM...WENT CLOSER TO THE COOLER
EUROPEAN TEMPS WITH HIGHS FROM THE UPPER 40S NORTHWEST TO NEAR 60
SOUTHEAST. LOWS FOR SATURDAY NIGHT WILL RANGE FROM THE LOWER 30S
NORTHWEST TO AROUND 40 SOUTHEAST. WENT CLOSER TO THE COOLER EUROPEAN
TEMPS...WHICH HAD LOWS FROM THE MIDDLE 20S NORTH TO THE LOWER 30S
SOUTH.
FOR SUNDAY...THE EUROPEAN DRIES THINGS OUT AND CONTINUES TO BRING
A COLD AIRMASS INTO THE REGION. THIS OCCURS AS A 1030 PLUS HIGH
MOVES FROM THE UPPER MISSISSIPPI VALLEY TO THE GREAT LAKES.
THE GFS KEEPS SOME MOISTURE AROUND FOR A CHANCE OF A COLD RAIN.
FOR TEMPS HIGHS WILL RANGE FROM NEAR 50 NORTHWEST TO THE MIDDLE
50S SOUTH. THIS WAS CLOSER TO THE COOLER EUROPEAN MODEL.
LOWS FOR SUNDAY NIGHT WILL RANGE FROM THE LOWER 30S NORTH TO THE
LOWER 40S SOUTH. WENT CLOSE TO GMOS NUMBERS.
FOR MONDAY...AS THE SURFACE HIGH PUSHES TOWARD THE EASTERN SEABOARD
WE GET SOME WARM RETURN FLOW AHEAD OF THE NEXT SYSTEM COMING OUT OF
THE PLAINS. LOOKS LIKE SOME SHOWERS WILL CROSS THE REGION. HIGHS WILL
RANGE FROM THE UPPER 40S NORTHEAST TO THE UPPER 50S SOUTHEAST.
AS FAR AS POPS ARE CONCERN MADE SOME SLIGHT CHANGES TO MEX POPS FROM
FRIDAY THROUGH MONDAY. /17/
&&
.AVIATION...VFR CLEAR WILL PREVAIL AT ALL TAF SITES UNTIL AROUND 09Z
WHEN UPSTREAM CLOUD DECK OF 4-5K FEET SPREADS SEWD ACROSS THE
REGION. BREEZY NORTHNORTHWEST SURFACE WINDS WILL CONTINUE TO SUBSIDE
THROUGH THE OVERNIGHT HOURS TO AROUND 7 KNOTS. AS A STRONG UPPER
LEVEL TROUGH SWINGS ACROSS THE REGION LATE TONIGHT INTO TUESDAY...
THOSE CLOUDS DEVELOP AT LEAST OVER NORTH CENTRAL AND NORTHEAST
MISSISSIPPI 09-14Z LEADING TO SOME SNOW FLURRIES. THE CLOUDS SHOULD
EXPAND AFTER DAYBREAK TO MOST TAF LOCATIONS BUT THEN START TO ERODE
FROM SW TO NE AFTER 22Z IN THE AFTERNOON./40/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 29 40 24 53 / 3 1 0 0
MERIDIAN 28 39 20 51 / 3 6 0 0
VICKSBURG 31 42 25 54 / 3 0 0 0
HATTIESBURG 32 45 21 51 / 3 2 0 0
NATCHEZ 30 44 24 54 / 3 0 0 0
GREENVILLE 30 40 26 53 / 5 0 0 0
GREENWOOD 28 38 23 51 / 7 3 0 0
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
000
FXUS64 KJAN 192214
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
412 PM CST MON JAN 19 2009
.DISCUSSION...FORECAST TRENDS HAVE NOT CHANGED MUCH THIS RUN AND NOT
MUCH IN THE WAY OF FORECAST ADJUSTMENTS HAVE BEEN NECESSARY. A
RELATIVELY DEEP UPPER TROUGH REMAINS ON TRACK TO DROP INTO THE
FORECAST AREA TONIGHT...INCREASING COLD AIR ADVECTION OVER AN
ALREADY CHILLY AIR MASS CURRENTLY IN PLACE. NRN/NERN ZONES WILL BE
ON THE WRN FRINGES OF THE BEST MOISTURE AND THE POSSIBILITY OF A FEW
FLURRIES WILL CONTINUE FOR THOSE AREAS LATE TONIGHT INTO EARLY
TUESDAY MORNING WITH NO ACCUMULATION EXPECTED. COLD AIR ADVECTION
AND A PERSISTENT DECK OF MOISTURE AROUND 850 MB WILL SET US UP FOR A
COLD DAY TOMORROW. THE ONLY SIGNIFICANT ADJUSTMENTS MADE TO THE
FORECAST INVOLVE TEMPERATURES WED AND WED NIGHT WHEN THE SLIGHTLY
COOLER MOS WAS PREFERRED OVER THE PREVIOUS FORECAST.
THE LAKE WIND ADVISORY CONTINUES FOR NERN/E CNTRL ZONES THROUGH
6 PM. WIND SPEEDS HAVE DECREASED SLOWLY OVER NWRN AREAS WHERE
CONDITIONS REMAIN JUST AT LAKE WIND ADVISORY CRITERIA BUT WILL
CONTINUE TO FALL SO WILL LET ADVISORY EXPIRE FOR THOSE AREAS AT
4 PM.
PREVIOUS DISCUSSION FOLLOWS...A STRONG S/W WILL DROP S/SE ON THE
BACK SIDE OF A LARGE E CONUS TROUGH TONIGHT. THIS FEATURE WILL HAVE
+100 KTS AT H5 ALONG WITH SUB 540M HGHTS FOR SOME OF THE AREA. THIS
CORRELATES TO NEG 2-3 STANDARD DEV FOR HGHTS AND IS RATHER RARE IN
THESE PARTS. THIS S/W WILL WORK TO SQUEEZE THE ATMS AND WITH SOME OK
MOISTURE AT AND BELOW H7...SOME FLURRIES/-SN WILL BE POSSIBLE AFTER
MIDNIGHT TONIGHT THROUGH MID MORNING TUE. MAIN AREAS TO SEE THIS
WILL BE ALONG AND N OF A GREENVILLE TO MERIDIAN LINE. NO ACCUM IS
EXPECTED.
THE 2ND...MORE POTENT S/W...WILL HELP TO INCREASE THE LOW LEVEL CAA
AND THE CWA WILL SEE NEG H925 AND H85 TEMPS. ACTUALLY H925 WILL RUN
BETWEEN -4 AND -7C WITH H85 BETWEEN -6 AND -12C. THESE VERY COLD H85
TEMPS ARE AROUND NEG 3 STANDARD DEV BELOW CLIMO VALUES AND SUPPORTS
A LARGE DEPARTURE FROM NORMAL TEMPS. WITH THIS...I HAVE LOWERED
HIGHS TUE 1-3 DEGREES WITH A RANGE FROM THE MID 30S TO MID 40S.
THERE WILL ALSO BE A DECENT STRATUS DECK FOR MOST OF THE DAY AND 40S
COULD BE TOUGH TO REACH.
TUE NIGHT...WE WILL SEE A SFC HIGH SETTLE OVER THE CWA. SKIES WILL
QUICKLY CLR AND WINDS WILL GO CALM. TEMPS WILL DROP QUICKLY INTO THE
MID/UPPER 20S AREA WIDE AND ON THEIR WAY TO LOWS BETWEEN 20-25
DEGREES. SOME UPPER TEENS ARE NOT OUT OF THE QUESTION. LOOK FOR A
HEAVY FROST AS WELL AS DEWPTS WILL BE IN THE MID 20S DURING THE
AFTERNOON AND WITH SOME CROSSOVER TEMPS LIKELY FROST MAY BE ON THE
THICK SIDE. THERE MAY ALSO BE SOME FREEZING FOG NEAR THE RIVERS AND
LARGE BODIES OF WATER. /CME/
.LONG TERM...WEDNESDAY THROUGH MONDAY...UPPER AIR PATTERN WILL
TRANSITION FROM A COOL PATTERN TO A WARMER PATTERN THEN BACK TO A
COOLER PATTERN FOR THE WEEKEND DURING THE PERIOD. MEDIUM RANGE AND
ENSEMBLE MODELS SEEM TO BE IN GENERALLY AGREEMENT. THERE SEEM TO BE
SOME QUESTION ON THIS WEEKENDS SYSTEM COMING(ASSOCIATED COLD FRONT
TIMING AND RAIN POPS) INTO THE REGION FOR THE LAST OF THE PERIOD.
CONFIDENCE IS NOT HIGH FOR THE FRIDAY INTO MONDAY OF THIS
PERIOD...DUE TO MODEL DIFFERENCES.
STARTING WITH WEDNESDAY IT WILL BE THE BEGINNING OF A TRANSITION
PERIOD WHERE THE AXIS OF THE UPPER TROUGH MOVES TO THE EASTERN
SEABOARD. 925 TEMPS WILL GRADUALLY WARM ON WEDNESDAY INTO THURSDAY.
FOR TEMPS WENT CLOSE TO GMOS GUIDANCE AS NAM LOOKED TO BE TOO COOL
DURING THE TRANSITION. HIGHS WILL BE FROM THE LOWER TO UPPER 50S.
FOR WEDNESDAY NIGHT KEPT WITH THE CURRENT LOWS FROM THE UPPER 20S
EAST TO THE MIDDLE 30S WEST.
FOR THURSDAY WE WILL START TO GET SOME RETURN FLOW OVER THE REGION.
925 TEMPS WILL RISE TO AROUND 10-13C. WE WILL START TO GET SOME FLAT
UPPER RIDGING ACROSS THE REGION. WENT WITH GMOS ON HIGHS FROM THE
UPPER 50S NORTHWEST TO THE UPPER 60S SOUTHEAST. FOR THURSDAY NIGHT
WENT CLOSE TO MEX GUIDANCE WITH LOWS FROM THE LOWER 40S NORTHEAST TO
THE LOWER 50S SOUTHWEST.
FOR FRIDAY INTO SATURDAY WE START GETTING SOME TIMING QUESTIONS WITH
A PASSAGE OF A COLD FRONT WITH AN ASSOCIATED SHORT WAVE.
THE EUROPEAN...GFS...AND ENSEMBLES HAVE SOME TIMING ISSUES OF A
FRONT THAT SEEMS TO HANG ACROSS THE SOUTH ON FRIDAY INTO SATURDAY.
THE EUROPEAN SEEMS TO BE THE MOST AGGRESSIVE IN PUSHING THE FRONT
AWAY FROM THE REGION BY SUNDAY MORNING...WHILE THE GFS AND ENSEMBLE
WITH THE BOUNDARY AROUND THE SOUTHERN PORTION OF THE REGION. WITH
THE 12Z EUROPEAN SOLUTION THERE MAY BE SOME WINTER PRECIP WITH THIS
SYSTEM ON SATURDAY IN THE NORTHWEST DELTA...BUT THE LATEST 00Z
SOLUTION DID NOT HAVE THE ICE...BUT WAS STILL COOL. WHILE THE OTHER
MODELS JUST HAD COLD SHOWERS. THIS SYSTEM WILL BEAR WATCHING AS MORE
COLD WITH IT GETS IN THE MODELS. FOR TEMPS WENT WITH THE GMOS WITH
HIGHS FROM THE UPPER 50S NORTHWEST TO THE UPPER 60S SOUTHEAST FOR
FRIDAY. FOR FRIDAY NIGHT WENT CLOSER TO THE COOLER EUROPEAN SOLUTION
WITH LOWS FROM THE UPPER 30S NORTHWEST TO THE MIDDLE 40S SOUTHEAST.
ON SATURDAY GFS TEMPS WERE TOO WARM...WENT CLOSER TO THE COOLER
EUROPEAN TEMPS WITH HIGHS FROM THE UPPER 40S NORTHWEST TO NEAR 60
SOUTHEAST. LOWS FOR SATURDAY NIGHT WILL RANGE FROM THE LOWER 30S
NORTHWEST TO AROUND 40 SOUTHEAST. WENT CLOSER TO THE COOLER EUROPEAN
TEMPS...WHICH HAD LOWS FROM THE MIDDLE 20S NORTH TO THE LOWER 30S
SOUTH.
FOR SUNDAY...THE EUROPEAN DRIES THINGS OUT AND CONTINUES TO BRING
A COLD AIRMASS INTO THE REGION. THIS OCCURS AS A 1030 PLUS HIGH
MOVES FROM THE UPPER MISSISSIPPI VALLEY TO THE GREAT LAKES.
THE GFS KEEPS SOME MOISTURE AROUND FOR A CHANCE OF A COLD RAIN.
FOR TEMPS HIGHS WILL RANGE FROM NEAR 50 NORTHWEST TO THE MIDDLE
50S SOUTH. THIS WAS CLOSER TO THE COOLER EUROPEAN MODEL.
LOWS FOR SUNDAY NIGHT WILL RANGE FROM THE LOWER 30S NORTH TO THE
LOWER 40S SOUTH. WENT CLOSE TO GMOS NUMBERS.
FOR MONDAY...AS THE SURFACE HIGH PUSHES TOWARD THE EASTERN SEABOARD
WE GET SOME WARM RETURN FLOW AHEAD OF THE NEXT SYSTEM COMING OUT OF
THE PLAINS. LOOKS LIKE SOME SHOWERS WILL CROSS THE REGION. HIGHS WILL
RANGE FROM THE UPPER 40S NORTHEAST TO THE UPPER 50S SOUTHEAST.
AS FAR AS POPS ARE CONCERN MADE SOME SLIGHT CHANGES TO MEX POPS FROM
FRIDAY THROUGH MONDAY. /17/
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES THROUGH
TUESDAY MORNING. BREEZY NORTH TO NORTHWEST SURFACE WINDS WILL BEGIN
TO SUBSIDE AROUND SUNSET THIS EVENING...AND CONTINUE TO SUBSIDE
THROUGH THE OVERNIGHT HOURS TO AROUND 5 KNOTS. SKIES WILL CLEAR
THROUGH MUCH OF THE OVERNIGHT HOURS...HOWEVER AS A STRONG UPPER
LEVEL TROUGH SWINGS ACROSS THE REGION LATE TONIGHT INTO TUESDAY...
SOME LOW TO MID LEVEL CLOUDS LOOK TO DEVELOP AT LEAST OVER NORTH
CENTRAL AND NORTHEAST MISSISSIPPI AFTER MIDNIGHT. THIS COULD LEAD
TO SOME SNOW FLURRIES AFTER MIDNIGHT AND INTO EARLY TUESDAY MORNING
NORTH OF A LINE FROM KGLH TO KMEI. NO ACCUMULATION IS EXPECTED. /19/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 29 40 24 53 / 3 1 0 0
MERIDIAN 28 39 20 51 / 3 6 0 0
VICKSBURG 31 42 25 54 / 3 0 0 0
HATTIESBURG 32 45 21 51 / 3 2 0 0
NATCHEZ 30 44 24 54 / 3 0 0 0
GREENVILLE 30 40 26 53 / 5 0 0 0
GREENWOOD 28 38 23 51 / 7 3 0 0
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...LAKE WIND ADVISORY UNTIL 6 PM CST THIS AFTERNOON FOR MSZ028>033-
037>039-043>046-048>052-056>058.
LA...NONE.
AR...NONE.
&&
$$
03/19/CME/17
000
FXUS64 KJAN 191723
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
1114 AM CST MON JAN 19 2009
.DISCUSSION...HAVE UPGRADED THE LAKE WIND ADVISORY TO A WIND
ADVISORY FOR AREAS ALONG THE MS RIVER CHANNEL. WINDS ARE BEING
FOCUSED ALONG THE REGION TO AROUND 25 MPH. LAKE WIND ADVISORY
REMAINS INTACT FOR OTHER AREAS NORTH OF THE INTERSTATE 20 CORRIDOR.
ALSO ADJUSTED TEMPERATURES SLIGHTLY COOLER OVER NRN ZONES DUE TO
COLD AIR ADVECTION THIS AFTERNOON.
&&
.PREVIOUS DISCUSSION...INTERESTING WEATHER IS IN STORE FOR THE
NEXT 48 HRS AS WE WILL SEE AN SWING IN TEMPS AS A FEW SIGNIFICANT
WEATHER FEATURES EFFECT THE CWA. WE WILL DEAL WITH A COLD FRONTAL
PASSAGE TODAY AND SOME BREEZY CONDITIONS. LATER TONIGHT...SNOW
FLURRIES WILL BE POSSIBLE ACROSS THE N. STAYING WITH THE WINTER TYPE
WEATHER...TEMPS TUE WILL BE RATHER COLD WITH MOST LOCATIONS
STRUGGLING TO REACH 40 DEGREES. TUE NIGHT WILL BE COLD WITH 20-25
FOR LOWS.
AS A SIDE NOTE...THERE LOOKS TO BE SOME ISSUE WITH TEMPS AT JAN AND
HBG. TECHS WILL BE LOOKING INTO THAT TODAY AND TUE.
FOR THE SPECIFICS...THE FIRST POTENT S/W WILL CONTINUE TO DROP S/SE
THROUGH MIDDAY. ASSOCIATED WITH THAT FEATURE IS A DECENT SFC LOW AND
ASSOCIATED COLD FRONT. THIS FRONT WILL IS CURRENTLY LOCATED FROM W
TN THROUGH CENTRAL AR AS OF 3AM. THIS FRONT WILL SWEEP ACROSS THE
CWA FROM THIS MORNING THROUGH MID AFTERNOON AND BRING SOME BREEZY
CONDITIONS AND SOME CLOUDS TO THE AREA. SKY CONDITIONS WILL VARY
TODAY WITH PARTLY CLOUDY PERIODS TO MO CLOUDY PERIODS. TEMPS WILL
RANGE FROM THE UPPER 40S ACROSS THE N TO MID 50S S...READINGS WILL
LIKELY HOLD STEADY IN THE MID/UPPER 40S ACROSS THE N AS THE FRONT
MOVE THROUGH BY MID MORNING. OTHER LOCATIONS SHOULD WARM AHEAD OF
THE FRONT THROUGH MIDDAY AND EARLY AFTERNOON.
BY TONIGHT...A STRONG S/W WILL DROP S/SE ON THE BACK SIDE OF A LARGE
E CONUS TROUGH. THIS FEATURE WILL HAVE +100 KTS AT H5 ALONG WITH SUB
540M HGHTS FOR SOME OF THE AREA. THIS CORRELATES TO NEG 2-3 STANDARD
DEV FOR HGHTS AND IS RATHER RARE IN THESE PARTS. THIS S/W WILL WORK
TO SQUEEZE THE ATMS AND WITH SOME OK MOISTURE AT AND BELOW H7...SOME
FLURRIES/-SN WILL BE POSSIBLE AFTER MIDNIGHT TONIGHT THROUGH MID
MORNING TUE. MAIN AREAS TO SEE THIS WILL BE ALONG AND N OF A
GREENVILLE TO MERIDIAN LINE. NO ACCUM IS EXPECTED.
THE 2ND...MORE POTENT S/W...WILL HELP TO INCREASE THE LOW LEVEL CAA
AND THE CWA WILL SEE NEG H925 AND H85 TEMPS. ACTUALLY H925 WILL RUN
BETWEEN -4 AND -7C WITH H85 BETWEEN -6 AND -12C. THESE VERY COLD H85
TEMPS ARE AROUND NEG 3 STANDARD DEV BELOW CLIMO VALUES AND SUPPORTS
A LARGE DEPARTURE FROM NORMAL TEMPS. WITH THIS...I HAVE LOWERED
HIGHS TUE 1-3 DEGREES WITH A RANGE FROM THE MID 30S TO MID 40S.
THERE WILL ALSO BE A DECENT STRATUS DECK FOR MOST OF THE DAY AND 40S
COULD BE TOUGH TO REACH.
TUE NIGHT...WE WILL SEE A SFC HIGH SETTLE OVER THE CWA. SKIES WILL
QUICKLY CLR AND WINDS WILL GO CALM. TEMPS WILL DROP QUICKLY INTO THE
MID/UPPER 20S AREA WIDE AND ON THEIR WAY TO LOWS BETWEEN 20-25
DEGREES. SOME UPPER TEENS ARE NOT OUT OF THE QUESTION. LOOK FOR A
HEAVY FROST AS WELL AS DEWPTS WILL BE IN THE MID 20S DURING THE
AFTERNOON AND WITH SOME CROSSOVER TEMPS LIKELY FROST MAY BE ON THE
THICK SIDE. THEIR MAY ALSO BE SOME FREEZING FOG NEAR THE RIVERS AND
LARGE BODIES OF WATER. /CME/
.LONG TERM...WEDNESDAY THROUGH MONDAY...UPPER AIR PATTERN WILL
TRANSITION FROM A COOL PATTERN TO A WARMER PATTERN THEN BACK TO A
COOLER PATTERN FOR THE WEEKEND DURING THE PERIOD. MEDIUM RANGE AND
ENSEMBLE MODELS SEEM TO BE IN GENERALLY AGREEMENT. THERE SEEM TO BE
SOME QUESTION ON THIS WEEKENDS SYSTEM COMING(ASSOCIATED COLD FRONT
TIMING AND RAIN POPS) INTO THE REGION FOR THE LAST OF THE PERIOD.
CONFIDENCE IS NOT HIGH FOR THE FRIDAY INTO MONDAY OF THIS
PERIOD...DUE TO MODEL DIFFERENCES.
STARTING WITH WEDNESDAY IT WILL BE THE BEGINNING OF A TRANSITION
PERIOD WHERE THE AXIS OF THE UPPER TROUGH MOVES TO THE EASTERN
SEABOARD. 925 TEMPS WILL GRADUALLY WARM ON WEDNESDAY INTO THURSDAY.
FOR TEMPS WENT CLOSE TO GMOS GUIDANCE AS NAM LOOKED TO BE TOO COOL
DURING THE TRANSITION. HIGHS WILL BE FROM THE LOWER TO UPPER 50S.
FOR WEDNESDAY NIGHT KEPT WITH THE CURRENT LOWS FROM THE UPPER 20S
EAST TO THE MIDDLE 30S WEST.
FOR THURSDAY WE WILL START TO GET SOME RETURN FLOW OVER THE REGION.
925 TEMPS WILL RISE TO AROUND 10-13C. WE WILL START TO GET SOME FLAT
UPPER RIDGING ACROSS THE REGION. WENT WITH GMOS ON HIGHS FROM THE
UPPER 50S NORTHWEST TO THE UPPER 60S SOUTHEAST. FOR THURSDAY NIGHT
WENT CLOSE TO MEX GUIDANCE WITH LOWS FROM THE LOWER 40S NORTHEAST TO
THE LOWER 50S SOUTHWEST.
FOR FRIDAY INTO SATURDAY WE START GETTING SOME TIMING QUESTIONS WITH
A PASSAGE OF A COLD FRONT WITH AN ASSOCIATED SHORT WAVE.
THE EUROPEAN...GFS...AND ENSEMBLES HAVE SOME TIMING ISSUES OF A
FRONT THAT SEEMS TO HANG ACROSS THE SOUTH ON FRIDAY INTO SATURDAY.
THE EUROPEAN SEEMS TO BE THE MOST AGGRESSIVE IN PUSHING THE FRONT
AWAY FROM THE REGION BY SUNDAY MORNING...WHILE THE GFS AND ENSEMBLE
WITH THE BOUNDARY AROUND THE SOUTHERN PORTION OF THE REGION. WITH
THE 12Z EUROPEAN SOLUTION THERE MAY BE SOME WINTER PRECIP WITH THIS
SYSTEM ON SATURDAY IN THE NORTHWEST DELTA...BUT THE LATEST 00Z
SOLUTION DID NOT HAVE THE ICE...BUT WAS STILL COOL. WHILE THE OTHER
MODELS JUST HAD COLD SHOWERS. THIS SYSTEM WILL BEAR WATCHING AS MORE
COLD WITH IT GETS IN THE MODELS. FOR TEMPS WENT WITH THE GMOS WITH
HIGHS FROM THE UPPER 50S NORTHWEST TO THE UPPER 60S SOUTHEAST FOR
FRIDAY. FOR FRIDAY NIGHT WENT CLOSER TO THE COOLER EUROPEAN SOLUTION
WITH LOWS FROM THE UPPER 30S NORTHWEST TO THE MIDDLE 40S SOUTHEAST.
ON SATURDAY GFS TEMPS WERE TOO WARM...WENT CLOSER TO THE COOLER
EUROPEAN TEMPS WITH HIGHS FROM THE UPPER 40S NORTHWEST TO NEAR 60
SOUTHEAST. LOWS FOR SATURDAY NIGHT WILL RANGE FROM THE LOWER 30S
NORTHWEST TO AROUND 40 SOUTHEAST. WENT CLOSER TO THE COOLER EUROPEAN
TEMPS...WHICH HAD LOWS FROM THE MIDDLE 20S NORTH TO THE LOWER 30S
SOUTH.
FOR SUNDAY...THE EUROPEAN DRIES THINGS OUT AND CONTINUES TO BRING
A COLD AIRMASS INTO THE REGION. THIS OCCURS AS A 1030 PLUS HIGH
MOVES FROM THE UPPER MISSISSIPPI VALLEY TO THE GREAT LAKES.
THE GFS KEEPS SOME MOISTURE AROUND FOR A CHANCE OF A COLD RAIN.
FOR TEMPS HIGHS WILL RANGE FROM NEAR 50 NORTHWEST TO THE MIDDLE
50S SOUTH. THIS WAS CLOSER TO THE COOLER EUROPEAN MODEL.
LOWS FOR SUNDAY NIGHT WILL RANGE FROM THE LOWER 30S NORTH TO THE
LOWER 40S SOUTH. WENT CLOSE TO GMOS NUMBERS.
FOR MONDAY...AS THE SURFACE HIGH PUSHES TOWARD THE EASTERN SEABOARD
WE GET SOME WARM RETURN FLOW AHEAD OF THE NEXT SYSTEM COMING OUT OF
THE PLAINS. LOOKS LIKE SOME SHOWERS WILL CROSS THE REGION. HIGHS WILL
RANGE FROM THE UPPER 40S NORTHEAST TO THE UPPER 50S SOUTHEAST.
AS FAR AS POPS ARE CONCERN MADE SOME SLIGHT CHANGES TO MEX POPS FROM
FRIDAY THROUGH MONDAY. /17/
&&
.AVIATION...NORTH TO NORTHWEST SURFACE WINDS SUSTAINED BETWEEN 15-20
KNOTS AND GUSTING AT TIMES AROUND 25 KNOTS OR HIGHER...REMAIN THE
MAIN FOCUS AT MOST TAF SITES TODAY. THIS IN ADDITIONS TO SOME CLOUD
COVER HANGING AROUND. DESPITE THIS...LOOK FOR VFR CONDITIONS TO
PREVAIL AT MOST LOCATIONS OVER THE NEXT 24 HOURS. THE ONLY EXCEPTION
TO THIS WILL BE AT THE NORTHERN SITES WHICH COULD SEE A BRIEF PERIOD
OF MVFR CEILINGS THIS AFTERNOON...BUT FORECAST SOUNDINGS KEEP THEM
ABOVE 3000 FEET WITH THE EXCEPTION BEING KGTR. SKIES WILL BEGIN TO
CLEAR TONIGHT AS NORTHERLY WINDS TAPER OFF TO AROUND 5 KNOTS...BUT
WILL REBOUND SHORTLY AFTER SUNRISE TOMORROW MORNING...AS WILL THE
CLOUDS...WITH BREEZY CONDITIONS EXPECTED ONCE AGAIN TUESDAY. /19/
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...LAKE WIND ADVISORY UNTIL 6 PM CST THIS AFTERNOON FOR MSZ028>033-
037>039-043>046-048>052-056>058.
LAKE WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR MSZ025>027-
036-042.
WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR MSZ018-019-034-
035-040-041-047.
LA...LAKE WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR LAZ007-015-
023.
WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR LAZ008-009-016-
025.
AR...LAKE WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR ARZ074.
WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR ARZ075.
&&
$$
03/CME
17/19
000
FXUS64 KJAN 190955
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
353 AM CST MON JAN 19 2009
.SHORT TERM...NTERESTING WEATHER IS IN STORE FOR THE NEXT 48 HRS AS
WE WILL SEE AN SWING IN TEMPS AS A FEW SIGNIFICANT WEATHER FEATURES
EFFECT THE CWA. WE WILL DEAL WITH A COLD FRONTAL PASSAGE TODAY AND
SOME BREEZY CONDITIONS. LATER TONIGHT...SNOW FLURRIES WILL BE
POSSIBLE ACROSS THE N. STAYING WITH THE WINTER TYPE WEATHER...TEMPS
TUE WILL BE RATHER COLD WITH MOST LOCATIONS STRUGGLING TO REACH 40
DEGREES. TUE NIGHT WILL BE COLD WITH 20-25 FOR LOWS.
AS A SIDE NOTE...THERE LOOKS TO BE SOME ISSUE WITH TEMPS AT JAN AND
HBG. TECHS WILL BE LOOKING INTO THAT TODAY AND TUE.
FOR THE SPECIFICS...THE FIRST POTENT S/W WILL CONTINUE TO DROP S/SE
THROUGH MIDDAY. ASSOCIATED WITH THAT FEATURE IS A DECENT SFC LOW AND
ASSOCIATED COLD FRONT. THIS FRONT WILL IS CURRENTLY LOCATED FROM W
TN THROUGH CENTRAL AR AS OF 3AM. THIS FRONT WILL SWEEP ACROSS THE
CWA FROM THIS MORNING THROUGH MID AFTERNOON AND BRING SOME BREEZY
CONDITIONS AND SOME CLOUDS TO THE AREA. SKY CONDITIONS WILL VARY
TODAY WITH PARTLY CLOUDY PERIODS TO MO CLOUDY PERIODS. TEMPS WILL
RANGE FROM THE UPPER 40S ACROSS THE N TO MID 50S S...READINGS WILL
LIKELY HOLD STEADY IN THE MID/UPPER 40S ACROSS THE N AS THE FRONT
MOVE THROUGH BY MID MORNING. OTHER LOCATIONS SHOULD WARM AHEAD OF
THE FRONT THROUGH MIDDAY AND EARLY AFTERNOON.
BY TONIGHT...A STRONG S/W WILL DROP S/SE ON THE BACK SIDE OF A LARGE
E CONUS TROUGH. THIS FEATURE WILL HAVE +100 KTS AT H5 ALONG WITH SUB
540M HGHTS FOR SOME OF THE AREA. THIS CORRELATES TO NEG 2-3 STANDARD
DEV FOR HGHTS AND IS RATHER RARE IN THESE PARTS. THIS S/W WILL WORK
TO SQUEEZE THE ATMS AND WITH SOME OK MOISTURE AT AND BELOW H7...SOME
FLURRIES/-SN WILL BE POSSIBLE AFTER MIDNIGHT TONIGHT THROUGH MID
MORNING TUE. MAIN AREAS TO SEE THIS WILL BE ALONG AND N OF A
GREENVILLE TO MERIDIAN LINE. NO ACCUM IS EXPECTED.
THE 2ND...MORE POTENT S/W...WILL HELP TO INCREASE THE LOW LEVEL CAA
AND THE CWA WILL SEE NEG H925 AND H85 TEMPS. ACTUALLY H925 WILL RUN
BETWEEN -4 AND -7C WITH H85 BETWEEN -6 AND -12C. THESE VERY COLD H85
TEMPS ARE AROUND NEG 3 STANDARD DEV BELOW CLIMO VALUES AND SUPPORTS
A LARGE DEPARTURE FROM NORMAL TEMPS. WITH THIS...I HAVE LOWERED
HIGHS TUE 1-3 DEGREES WITH A RANGE FROM THE MID 30S TO MID 40S.
THERE WILL ALSO BE A DECENT STRATUS DECK FOR MOST OF THE DAY AND 40S
COULD BE TOUGH TO REACH.
TUE NIGHT...WE WILL SEE A SFC HIGH SETTLE OVER THE CWA. SKIES WILL
QUICKLY CLR AND WINDS WILL GO CALM. TEMPS WILL DROP QUICKLY INTO THE
MID/UPPER 20S AREA WIDE AND ON THEIR WAY TO LOWS BETWEEN 20-25
DEGREES. SOME UPPER TEENS ARE NOT OUT OF THE QUESTION. LOOK FOR A
HEAVY FROST AS WELL AS DEWPTS WILL BE IN THE MID 20S DURING THE
AFTERNOON AND WITH SOME CROSSOVER TEMPS LIKELY FROST MAY BE ON THE
THICK SIDE. THEIR MAY ALSO BE SOME FREEZING FOG NEAR THE RIVERS AND
LARGE BODIES OF WATER. /CME/
.LONG TERM...WEDNESDAY THROUGH MONDAY...UPPER AIR PATTERN WILL
TRANSITION FROM A COOL PATTERN TO A WARMER PATTERN THEN BACK TO A
COOLER PATTERN FOR THE WEEKEND DURING THE PERIOD. MEDIUM RANGE AND
ENSEMBLE MODELS SEEM TO BE IN GENERALLY AGREEMENT. THERE SEEM TO BE
SOME QUESTION ON THIS WEEKENDS SYSTEM COMING(ASSOCIATED COLD FRONT
TIMING AND RAIN POPS) INTO THE REGION FOR THE LAST OF THE PERIOD.
CONFIDENCE IS NOT HIGH FOR THE FRIDAY INTO MONDAY OF THIS
PERIOD...DUE TO MODEL DIFFERENCES.
STARTING WITH WEDNESDAY IT WILL BE THE BEGINNING OF A TRANSITION
PERIOD WHERE THE AXIS OF THE UPPER TROUGH MOVES TO THE EASTERN
SEABOARD. 925 TEMPS WILL GRADUALLY WARM ON WEDNESDAY INTO THURSDAY.
FOR TEMPS WENT CLOSE TO GMOS GUIDANCE AS NAM LOOKED TO BE TOO COOL
DURING THE TRANSITION. HIGHS WILL BE FROM THE LOWER TO UPPER 50S.
FOR WEDNESDAY NIGHT KEPT WITH THE CURRENT LOWS FROM THE UPPER 20S
EAST TO THE MIDDLE 30S WEST.
FOR THURSDAY WE WILL START TO GET SOME RETURN FLOW OVER THE REGION.
925 TEMPS WILL RISE TO AROUND 10-13C. WE WILL START TO GET SOME FLAT
UPPER RIDGING ACROSS THE REGION. WENT WITH GMOS ON HIGHS FROM THE
UPPER 50S NORTHWEST TO THE UPPER 60S SOUTHEAST. FOR THURSDAY NIGHT
WENT CLOSE TO MEX GUIDANCE WITH LOWS FROM THE LOWER 40S NORTHEAST TO
THE LOWER 50S SOUTHWEST.
FOR FRIDAY INTO SATURDAY WE START GETTING SOME TIMING QUESTIONS WITH
A PASSAGE OF A COLD FRONT WITH AN ASSOCIATED SHORT WAVE.
THE EUROPEAN...GFS...AND ENSEMBLES HAVE SOME TIMING ISSUES OF A
FRONT THAT SEEMS TO HANG ACROSS THE SOUTH ON FRIDAY INTO SATURDAY.
THE EUROPEAN SEEMS TO BE THE MOST AGGRESSIVE IN PUSHING THE FRONT
AWAY FROM THE REGION BY SUNDAY MORNING...WHILE THE GFS AND ENSEMBLE
WITH THE BOUNDARY AROUND THE SOUTHERN PORTION OF THE REGION. WITH
THE 12Z EUROPEAN SOLUTION THERE MAY BE SOME WINTER PRECIP WITH THIS
SYSTEM ON SATURDAY IN THE NORTHWEST DELTA...BUT THE LATEST 00Z
SOLUTION DID NOT HAVE THE ICE...BUT WAS STILL COOL. WHILE THE OTHER
MODELS JUST HAD COLD SHOWERS. THIS SYSTEM WILL BEAR WATCHING AS MORE
COLD WITH IT GETS IN THE MODELS. FOR TEMPS WENT WITH THE GMOS WITH
HIGHS FROM THE UPPER 50S NORTHWEST TO THE UPPER 60S SOUTHEAST FOR
FRIDAY. FOR FRIDAY NIGHT WENT CLOSER TO THE COOLER EUROPEAN SOLUTION
WITH LOWS FROM THE UPPER 30S NORTHWEST TO THE MIDDLE 40S SOUTHEAST.
ON SATURDAY GFS TEMPS WERE TOO WARM...WENT CLOSER TO THE COOLER
EUROPEAN TEMPS WITH HIGHS FROM THE UPPER 40S NORTHWEST TO NEAR 60
SOUTHEAST. LOWS FOR SATURDAY NIGHT WILL RANGE FROM THE LOWER 30S
NORTHWEST TO AROUND 40 SOUTHEAST. WENT CLOSER TO THE COOLER EUROPEAN
TEMPS...WHICH HAD LOWS FROM THE MIDDLE 20S NORTH TO THE LOWER 30S
SOUTH.
FOR SUNDAY...THE EUROPEAN DRIES THINGS OUT AND CONTINUES TO BRING
A COLD AIRMASS INTO THE REGION. THIS OCCURS AS A 1030 PLUS HIGH
MOVES FROM THE UPPER MISSISSIPPI VALLEY TO THE GREAT LAKES.
THE GFS KEEPS SOME MOISTURE AROUND FOR A CHANCE OF A COLD RAIN.
FOR TEMPS HIGHS WILL RANGE FROM NEAR 50 NORTHWEST TO THE MIDDLE
50S SOUTH. THIS WAS CLOSER TO THE COOLER EUROPEAN MODEL.
LOWS FOR SUNDAY NIGHT WILL RANGE FROM THE LOWER 30S NORTH TO THE
LOWER 40S SOUTH. WENT CLOSE TO GMOS NUMBERS.
FOR MONDAY...AS THE SURFACE HIGH PUSHES TOWARD THE EASTERN SEABOARD
WE GET SOME WARM RETURN FLOW AHEAD OF THE NEXT SYSTEM COMING OUT OF
THE PLAINS. LOOKS LIKE SOME SHOWERS WILL CROSS THE REGION. HIGHS WILL
RANGE FROM THE UPPER 40S NORTHEAST TO THE UPPER 50S SOUTHEAST.
AS FAR AS POPS ARE CONCERN MADE SOME SLIGHT CHANGES TO MEX POPS FROM
FRIDAY THROUGH MONDAY. /17/
&&
.AVIATION...MAIN FOCUS WILL BE WITH SFC WINDS FOR TODAY. BESIDES
THAT...THERE WILL BE SOME CLOUDS AROUND...BUT MOST LOCATIONS WILL
REMAIN IN VFR CONDITIONS. THE NORTHERN SITES MAY SEE A BRIEF PERIOD
OF MVFR CEILINGS...BUT FORECAST SOUNDINGS AND GUID KEEP THEM ABV
3KFT WITH THE EXCEPTION BEING GTR. THE N SITES MAY ALSO SEE A SMALL
PERIOD OF FLURRIES. NO VIS RESTRICTIONS ARE EXPECTED WITH THAT.
BEYOND 24 HRS...LOOK FOR DECENT NW/N WINDS TUE ALONG WITH A DECENT
STRATUS DECK AROUND 2700-4000 FT. SKIES WILL CLR TUE EVENING WITH A
COLD NIGHT ON TAP. /CME/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 50 29 40 24 / 0 2 1 0
MERIDIAN 52 28 39 20 / 0 4 6 0
VICKSBURG 52 31 42 25 / 0 0 0 0
HATTIESBURG 57 32 45 21 / 0 0 2 0
NATCHEZ 53 30 44 24 / 0 0 0 0
GREENVILLE 47 30 40 26 / 0 15 0 0
GREENWOOD 47 28 38 23 / 0 18 3 0
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...LAKE WIND ADVISORY FROM 9 AM THIS MORNING TO 6 PM CST THIS
AFTERNOON FOR MSZ028>033-037>039-043>046-048>052-056>058.
LAKE WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR MSZ018-019-
025>027-034>036-040>042-047.
LA...LAKE WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR LAZ007>009-
015-016-023-025.
AR...LAKE WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR ARZ074-075.
&&
$$
CME
17
000
FXUS64 KJAN 190245 AAA
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
830 PM CST SUN JAN 18 2009
.UPDATE...HIGH THIN CIRRUS WAS NOTED OVER OUR NORTHERN MOST ZONES
WITH CLEAR SKIES ELSEWHERE. THICKER CLOUDS EXPECTED MONDAY AS
DISTURBANCE MOVES OVERHEAD SO HAVE ADJUSTED CLOUD COVER TONIGHT.
TEMPERATURE CURVES WERE ADJUSTED BUT LOW TEMPS LOOK ON TRACK. NO
OTHER CHANGES NEEDED. /22/
&&
.PREVIOUS DISCUSSION...SHORT TERM...A FEW HIGHER CLOUDS HAVE PUSHED
INTO THE REGION FROM THE NORTH...ASSOCIATED WITH A DRY WAVE THAT
WILL DROP INTO AREAS LATE TONIGHT AND EARLY MONDAY. DRIER DEW POINTS
HAVE FINALLY BEGUN TO PUSH INTO THE AREA WELL AFTER LAST NIGHTS COLD
FRONT. CONSIDERED INCREASING OVERNIGHT LOWS SLIGHTLY DUE TO
POSSIBILITY OF CLOUD COVER BUT SEEING THE GLH DEW POINT DROP FROM 40
TO 29 THIS AFTERNOON HAS CONVINCED ME THAT THE COOLER SOLUTION MAY
BE THE BEST WAY TO GO...ESPECIALLY WITH UPSTREAM CLOUD COVER
BEGINNING TO LOOK SPLOTCHY AND MID 20S DEW POINTS POSITIONED JUST
UPSTREAM.
THE WEAK WAVE WILL MAINTAIN DRY WEATHER BUT WILL PACK A BETTER PUNCH
AS FAR AS TEMPERATURES ARE CONCERNED. 850 MB TEMPS DROP BELOW
FREEZING FOR ALL OF THE FORECAST AREA DURING THE DAY MONDAY WITH -10
DEGS FORECAST AT 850 MBS OVER NERN MS LATE IN THE DAY. THE 850 MB
TROUGH WILL DROP ACROSS THE REGION DURING THE DAY...PROVIDING A
PERSISTENT STRATOCU DECK ALONG WITH STRONG COLD AIR ADVECTION TO
RESULT IN THE HIGHER TEMPERATURES BEING REACHED EARLY IN THE DAY FOR
SOME NORTH AND CENTRAL ZONES. WILL FOLLOW THE SLIGHTLY COOLER MOS
SOLUTION FOR TOMORROW NIGHT.
THE NEXT STRONGER SHORTWAVE WILL DROP INTO THE REGION LATE MONDAY
NIGHT. WE WILL SEE DEEPENING MOISTURE WITH THIS VERY DEEP UPPER
TROUGH. THE LATEST MODEL RUNS ARE TRENDING DRIER BUT FLURRIES REMAIN
POSSIBLE OVER SECTIONS OF NORTH AND EAST MISSISSIPPI LATE MONDAY
NIGHT INTO EARLY TUESDAY MORNING. THE AIR MASS DRIES RAPIDLY EARLY
TUESDAY TO END THE CHANCE OF PRECIP QUICKLY. WILL FOLLOW SLIGHTLY
COOLER CURRENT FORECAST FOR TUESDAY DUE TO INTENSE COLD AIR
ADVECTION THROUGH MUCH OF THE ATMOSPHERE WITH THIS STRONG WAVE. THE
MODELS MAINTAIN A MOIST LAYER AROUND 850 MB MUCH OF THE DAY. WITH
PERSISTENT CLOUDS AND GUSTY NORTHERLY WINDS RAW CONDITIONS LOOK TO
BE ON TAP TUESDAY. 850 MB TEMPERATURES ARE FORECAST TO DROP TO
AROUND -12 DEGS OVER NRN SECTIONS OF THE FORECAST AREA AND LAKE WIND
ADVISORY CRITERIA LOOKS LIKELY FOR AFTERNOON WINDS. LOWERED MOS
TEMPS A BIT FOR THE AFTERNOON. MOS IS TRENDING COOLER WITH THIS
SCENARIO AND FOLLOWED COLDER MOS LOWS TUESDAY NIGHT WITH LOWER TO
MID 20S AS SURFACE RIDGING PUSHES INTO CENTRAL AND SRN ZONES. /03/
LONG TERM...THE MED RANGE/LONG TERM PORTION OF THE FORECAST REMAINS
DOMINATED BY COLD FIRST THEN WARMER WITH A FEW QUESTION MARKS THROWN
IN FOR THE LAST COUPLE PERIODS. TUE-WED WILL BE RATHER CHILLY AS THE
PATTERN WILL BE DOMINATED BY A DEEP/LARGE LONG WAVE TROUGH ACROSS
THE E CONUS. THINGS BECOME MORE ZONAL BY THU/FRI AND WE SHOULD SEE A
SOME KIND OF S/W MOVE ACROSS THE AREA FRI INTO SAT.
BY WED AFTERNOON SW RETURN FLOW WILL SETUP AS THE SFC HIGH SHIFTS A
TAD TO THE E/SE. EVEN WITH THAT RETURN FLOW...THE COLD START TO THE
DAY WILL LIMIT HOW WARM WE WILL GET. THIS RUN OF THE GUID IS COOLER
THAN PREV RUNS AND HAVE FOLLOWED. LOWER TO MID 50S LOOK GOOD.
THU/FRI WILL TRANSITION TO WARMER AS RETURN FLOW BECOME MORE
ENTRENCHED. EVEN WITH A COUPLE PERIODS OF RETURN FLOW...IT MAY TAKE
A WHILE TO GET DECENT MOISTURE BACK INTO THE AREA AS THE SFC HIGH
WILL SCOUR THE GULF PRETTY GOOD. GUID IS STILL TRYING HAVE LOWS ON
THE WARM SIDE TOO QUICKLY AND HAVE CONTINUED THE TREND OF LOWER THEM
BOTH THU/FRI MORNINGS. COLD GROUND...DRY AIR AND THE LINGERING SFC
RIDGE AXIS SHOULD ALLOW FOR THAT SETUP.
THERE IS SOME TIMING ISSUES FOR THE NEXT FRONT WITH THE GFS FASTER
THAN THE EURO. I LIKE SOMETHING IN BETWEEN WITH THE FRONT AND THE
NEXT RAIN CHANCES TO COME IN BY FRI INTO FRI EVENING. I WILL HOLD
ONTO THE LINGERING 20% THROUGH THE WEEKEND AS THERE REMAINS MANY
QUESTION MARKS ON IF THERE WILL BE A QUICK MOISTURE RETURN BY SAT AS
A DETACHED S/W OVER THE SW MAY MOVE OVER THE AREA. THIS FRI-SUN
PERIOD WILL LIKELY CONTINUE TO HAVE TIMING ISSUES SO IT MAY TAKE A
BIT LONGER TO GET THOSE PERIODS FIGURED OUT. /CME/
&&
.AVIATION...SKIES HAVE CLEARED AT ALL TAF SITES IN THE WAKE OF THIS
MORNING`S COLD FRONT PASSAGE. THEREFORE...VFR CONDITIONS ARE
EXPECTED TO PREVAIL AT ALL SITES THIS AFTERNOON AND EVENING...AS
WELL AS THROUGH THE OVERNIGHT HOURS TONIGHT. /19/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 36 50 30 42 / 0 6 1 1
MERIDIAN 35 52 30 39 / 0 3 8 6
VICKSBURG 36 51 32 43 / 0 9 0 0
HATTIESBURG 40 58 31 45 / 0 5 3 2
NATCHEZ 38 54 29 45 / 0 9 0 0
GREENVILLE 35 47 31 41 / 0 6 5 0
GREENWOOD 34 47 29 40 / 0 5 9 3
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
03/19/CME
000
FXUS64 KJAN 182253 CCA
AFDJAN
AREA FORECAST DISCUSSION...CORRECTION
NATIONAL WEATHER SERVICE JACKSON MS
449 PM CST SUN JAN 18 2009
.SHORT TERM...A FEW HIGHER CLOUDS HAVE PUSHED INTO THE REGION FROM
THE NORTH...ASSOCIATED WITH A DRY WAVE THAT WILL DROP INTO AREAS
LATE TONIGHT AND EARLY MONDAY. DRIER DEW POINTS HAVE FINALLY BEGUN
TO PUSH INTO THE AREA WELL AFTER LAST NIGHTS COLD FRONT. CONSIDERED
INCREASING OVERNIGHT LOWS SLIGHTLY DUE TO POSSIBILITY OF CLOUD COVER
BUT SEEING THE GLH DEW POINT DROP FROM 40 TO 29 THIS AFTERNOON HAS
CONVINCED ME THAT THE COOLER SOLUTION MAY BE THE BEST WAY TO
GO...ESPECIALLY WITH UPSTREAM CLOUD COVER BEGINNING TO LOOK SPLOTCHY
AND MID 20S DEW POINTS POSITIONED JUST UPSTREAM.
THE WEAK WAVE WILL MAINTAIN DRY WEATHER BUT WILL PACK A BETTER PUNCH
AS FAR AS TEMPERATURES ARE CONCERNED. 850 MB TEMPS DROP BELOW
FREEZING FOR ALL OF THE FORECAST AREA DURING THE DAY MONDAY WITH -10
DEGS FORECAST AT 850 MBS OVER NERN MS LATE IN THE DAY. THE 850 MB
TROUGH WILL DROP ACROSS THE REGION DURING THE DAY...PROVIDING A
PERSISTENT STRATOCU DECK ALONG WITH STRONG COLD AIR ADVECTION TO
RESULT IN THE HIGHER TEMPERATURES BEING REACHED EARLY IN THE DAY FOR
SOME NORTH AND CENTRAL ZONES. WILL FOLLOW THE SLIGHTLY COOLER MOS
SOLUTION FOR TOMORROW NIGHT.
THE NEXT STRONGER SHORTWAVE WILL DROP INTO THE REGION LATE MONDAY
NIGHT. WE WILL SEE DEEPENING MOISTURE WITH THIS VERY DEEP UPPER
TROUGH. THE LATEST MODEL RUNS ARE TRENDING DRIER BUT FLURRIES REMAIN
POSSIBLE OVER SECTIONS OF NORTH AND EAST MISSISSIPPI LATE MONDAY
NIGHT INTO EARLY TUESDAY MORNING. THE AIR MASS DRIES RAPIDLY EARLY
TUESDAY TO END THE CHANCE OF PRECIP QUICKLY. WILL FOLLOW SLIGHTLY
COOLER CURRENT FORECAST FOR TUESDAY DUE TO INTENSE COLD AIR
ADVECTION THROUGH MUCH OF THE ATMOSPHERE WITH THIS STRONG WAVE. THE
MODELS MAINTAIN A MOIST LAYER AROUND 850 MB MUCH OF THE DAY. WITH
PERSISTENT CLOUDS AND GUSTY NORTHERLY WINDS RAW CONDITIONS LOOK TO
BE ON TAP TUESDAY. 850 MB TEMPERATURES ARE FORECAST TO DROP TO
AROUND -12 DEGS OVER NRN SECTIONS OF THE FORECAST AREA AND LAKE WIND
ADVISORY CRITERIA LOOKS LIKELY FOR AFTERNOON WINDS. LOWERED MOS
TEMPS A BIT FOR THE AFTERNOON. MOS IS TRENDING COOLER WITH THIS
SCENARIO AND FOLLOWED COLDER MOS LOWS TUESDAY NIGHT WITH LOWER TO
MID 20S AS SURFACE RIDGING PUSHES INTO CENTRAL AND SRN ZONES. /03/
.LONG TERM...THE MED RANGE/LONG TERM PORTION OF THE FORECAST REMAINS
DOMINATED BY COLD FIRST THEN WARMER WITH A FEW QUESTION MARKS THROWN
IN FOR THE LAST COUPLE PERIODS. TUE-WED WILL BE RATHER CHILLY AS THE
PATTERN WILL BE DOMINATED BY A DEEP/LARGE LONG WAVE TROUGH ACROSS
THE E CONUS. THINGS BECOME MORE ZONAL BY THU/FRI AND WE SHOULD SEE A
SOME KIND OF S/W MOVE ACROSS THE AREA FRI INTO SAT.
BY WED AFTERNOON SW RETURN FLOW WILL SETUP AS THE SFC HIGH SHIFTS A
TAD TO THE E/SE. EVEN WITH THAT RETURN FLOW...THE COLD START TO THE
DAY WILL LIMIT HOW WARM WE WILL GET. THIS RUN OF THE GUID IS COOLER
THAN PREV RUNS AND HAVE FOLLOWED. LOWER TO MID 50S LOOK GOOD.
THU/FRI WILL TRANSITION TO WARMER AS RETURN FLOW BECOME MORE
ENTRENCHED. EVEN WITH A COUPLE PERIODS OF RETURN FLOW...IT MAY TAKE
A WHILE TO GET DECENT MOISTURE BACK INTO THE AREA AS THE SFC HIGH
WILL SCOUR THE GULF PRETTY GOOD. GUID IS STILL TRYING HAVE LOWS ON
THE WARM SIDE TOO QUICKLY AND HAVE CONTINUED THE TREND OF LOWER THEM
BOTH THU/FRI MORNINGS. COLD GROUND...DRY AIR AND THE LINGERING SFC
RIDGE AXIS SHOULD ALLOW FOR THAT SETUP.
THERE IS SOME TIMING ISSUES FOR THE NEXT FRONT WITH THE GFS FASTER
THAN THE EURO. I LIKE SOMETHING IN BETWEEN WITH THE FRONT AND THE
NEXT RAIN CHANCES TO COME IN BY FRI INTO FRI EVENING. I WILL HOLD
ONTO THE LINGERING 20% THROUGH THE WEEKEND AS THERE REMAINS MANY
QUESTION MARKS ON IF THERE WILL BE A QUICK MOISTURE RETURN BY SAT AS
A DETACHED S/W OVER THE SW MAY MOVE OVER THE AREA. THIS FRI-SUN
PERIOD WILL LIKELY CONTINUE TO HAVE TIMING ISSUES SO IT MAY TAKE A
BIT LONGER TO GET THOSE PERIODS FIGURED OUT. /CME/
&&
.AVIATION...SKIES HAVE CLEARED AT ALL TAF SITES IN THE WAKE OF THIS
MORNING`S COLD FRONT PASSAGE. THEREFORE...VFR CONDITIONS ARE
EXPECTED TO PREVAIL AT ALL SITES THIS AFTERNOON AND EVENING...AS
WELL AS THROUGH THE OVERNIGHT HOURS TONIGHT. /19/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 36 50 30 42 / 0 6 1 1
MERIDIAN 35 52 30 39 / 0 3 8 6
VICKSBURG 36 51 32 43 / 0 9 0 0
HATTIESBURG 40 58 31 45 / 0 5 3 2
NATCHEZ 38 54 29 45 / 0 9 0 0
GREENVILLE 35 47 31 41 / 0 6 5 0
GREENWOOD 34 47 29 40 / 0 5 9 3
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
03/19/CME
000
FXUS64 KJAN 182151
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
307 PM CST SUN JAN 18 2009
.SHORT TERM...A FEW HIGHER CLOUDS HAVE PUSHED INTO THE REGION FROM
THE NORTH...ASSOCIATED WITH A DRY WAVE THAT WILL DROP INTO AREAS
LATE TONIGHT AND EARLY MONDAY. DRIER DEW POINTS HAVE FINALLY BEGUN
TO PUSH INTO THE AREA WELL AFTER LAST NIGHTS COLD FRONT. CONSIDERED
INCREASING OVERNIGHT LOWS SLIGHTLY DUE TO POSSIBILITY OF CLOUD COVER
BUT SEEING THE GLH DEW POINT DROP FROM 40 TO 29 THIS AFTERNOON HAS
CONVINCED ME THAT THE COOLER SOLUTION MAY BE THE BEST WAY TO
GO...ESPECIALLY WITH UPSTREAM CLOUD COVER BEGINNING TO LOOK SPLOTCHY
AND MID 20S DEW POINTS POSITIONED JUST UPSTREAM.
THE WEAK WAVE WILL MAINTAIN DRY WEATHER BUT WILL PACK A BETTER PUNCH
AS FAR AS TEMPERATURES ARE CONCERNED. 850 MB TEMPS DROP BELOW
FREEZING FOR ALL OF THE FORECAST AREA DURING THE DAY MONDAY WITH -10
DEGS FORECAST AT 850 MBS OVER NERN MS LATE IN THE DAY. THE 850 MB
TROUGH WILL DROP ACROSS THE REGION DURING THE DAY...PROVIDING A
PERSISTENT STRATOCU DECK ALONG WITH STRONG COLD AIR ADVECTION TO
RESULT IN THE HIGHER TEMPERATURES BEING REACHED EARLY IN THE DAY FOR
SOME NORTH AND CENTRAL ZONES. WILL FOLLOW THE SLIGHTLY COOLER MOS
SOLUTION FOR TOMORROW NIGHT.
THE NEXT STRONGER SHORTWAVE WILL DROP INTO THE REGION LATE MONDAY
NIGHT. WE WILL SEE DEEPENING MOISTURE WITH THIS VERY DEEP UPPER
TROUGH. THE LATEST MODEL RUNS ARE TRENDING DRIER BUT FLURRIES REMAIN
POSSIBLE OVER SECTIONS OF NORTH AND EAST MISSISSIPPI LATE MONDAY
NIGHT INTO EARLY TUESDAY MORNING. THE AIR MASS DRIES RAPIDLY EARLY
TUESDAY TO END THE CHANCE OF PRECIP QUICKLY. WILL FOLLOW SLIGHTLY
COOLER CURRENT FORECAST FOR TUESDAY DUE TO INTENSE COLD AIR
ADVECTION THROUGH MUCH OF THE ATMOSPHERE WITH THIS STRONG WAVE. THE
MODELS MAINTAIN A MOIST LAYER AROUND 850 MB MUCH OF THE DAY. WITH
PERSISTENT CLOUDS AND GUSTY NORTHERLY WINDS RAW CONDITIONS LOOK TO
BE ON TAP TUESDAY. 850 MB TEMPERATURES ARE FORECAST TO DROP TO
AROUND -12 DEGS OVER NRN SECTIONS OF THE FORECAST AREA AND LAKE WIND
ADVISORY CRITERIA LOOKS LIKELY FOR AFTERNOON WINDS. LOWERED MOS
TEMPS A BIT FOR THE AFTERNOON. MOS IS TRENDING COOLER WITH THIS
SCENARIO AND FOLLOWED COLDER MOS LOWS TUESDAY NIGHT WITH LOWER TO
MID 20S AS SURFACE RIDGING PUSHES INTO CENTRAL AND SRN ZONES.
.LONG TERM...THE MED RANGE/LONG TERM PORTION OF THE FORECAST REMAINS
DOMINATED BY COLD FIRST THEN WARMER WITH A FEW QUESTION MARKS THROWN
IN FOR THE LAST COUPLE PERIODS. TUE-WED WILL BE RATHER CHILLY AS THE
PATTERN WILL BE DOMINATED BY A DEEP/LARGE LONG WAVE TROUGH ACROSS
THE E CONUS. THINGS BECOME MORE ZONAL BY THU/FRI AND WE SHOULD SEE A
SOME KIND OF S/W MOVE ACROSS THE AREA FRI INTO SAT.
BY WED AFTERNOON SW RETURN FLOW WILL SETUP AS THE SFC HIGH SHIFTS A
TAD TO THE E/SE. EVEN WITH THAT RETURN FLOW...THE COLD START TO THE
DAY WILL LIMIT HOW WARM WE WILL GET. THIS RUN OF THE GUID IS COOLER
THAN PREV RUNS AND HAVE FOLLOWED. LOWER TO MID 50S LOOK GOOD.
THU/FRI WILL TRANSITION TO WARMER AS RETURN FLOW BECOME MORE
ENTRENCHED. EVEN WITH A COUPLE PERIODS OF RETURN FLOW...IT MAY TAKE
A WHILE TO GET DECENT MOISTURE BACK INTO THE AREA AS THE SFC HIGH
WILL SCOUR THE GULF PRETTY GOOD. GUID IS STILL TRYING HAVE LOWS ON
THE WARM SIDE TOO QUICKLY AND HAVE CONTINUED THE TREND OF LOWER THEM
BOTH THU/FRI MORNINGS. COLD GROUND...DRY AIR AND THE LINGERING SFC
RIDGE AXIS SHOULD ALLOW FOR THAT SETUP.
THERE IS SOME TIMING ISSUES FOR THE NEXT FRONT WITH THE GFS FASTER
THAN THE EURO. I LIKE SOMETHING IN BETWEEN WITH THE FRONT AND THE
NEXT RAIN CHANCES TO COME IN BY FRI INTO FRI EVENING. I WILL HOLD
ONTO THE LINGERING 20% THROUGH THE WEEKEND AS THERE REMAINS MANY
QUESTION MARKS ON IF THERE WILL BE A QUICK MOISTURE RETURN BY SAT AS
A DETACHED S/W OVER THE SW MAY MOVE OVER THE AREA. THIS FRI-SUN
PERIOD WILL LIKELY CONTINUE TO HAVE TIMING ISSUES SO IT MAY TAKE A
BIT LONGER TO GET THOSE PERIODS FIGURED OUT. /CME/
&&
.AVIATION...SKIES HAVE CLEARED AT ALL TAF SITES IN THE WAKE OF THIS
MORNING`S COLD FRONT PASSAGE. THEREFORE...VFR CONDITIONS ARE
EXPECTED TO PREVAIL AT ALL SITES THIS AFTERNOON AND EVENING...AS
WELL AS THROUGH THE OVERNIGHT HOURS TONIGHT. /19/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 61 36 50 30 / 0 0 6 1
MERIDIAN 61 35 52 30 / 0 0 3 8
VICKSBURG 63 36 51 32 / 1 0 9 0
HATTIESBURG 64 40 58 31 / 2 0 5 3
NATCHEZ 61 38 54 29 / 1 0 9 0
GREENVILLE 58 35 47 31 / 5 0 6 5
GREENWOOD 58 34 47 29 / 3 0 5 9
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
03/19/CME
000
FXUS64 KJAN 181722
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
1111 AM CST SUN JAN 18 2009
.DISCUSSION...TEMPERATURES ARE WARMING FASTER THAN PREVIOUSLY
INDICATED SO HAVE ADJUSTED AFTERNOON HIGHS FOR TODAY. CONTRARY TO
CONVENTIONAL CONDITIONS IN THE WAKE OF A COLD FRONT THE LATEST
OBSERVATIONS RUN FROM 11 TO 20 DEGREES WARMER THAN THIS TIME
YESTERDAY. REMOVED MENTION OF PRECIP FOR THE REGION AND ADJUSTED
CLOUD COVER PER CLEAR SKIES FROM LATEST OBSERVATIONS. A FEW HIGHER
CLOUDS MAY MOVE IN FROM THE NORTHWEST LATE TODAY BUT SKIES WILL
GENERALLY BE CLEAR ACROSS THE ARKLAMISS TODAY.
&&
.PREV DISCUSSION...402 AM CST SUN JAN 18 2009 SURFACE ANALYSIS
THIS MORNING SHOWS THE APPROACHING COLD FRONT STRETCHED ACROSS
SOUTHEAST ARKANSAS ALONG THE FRINGES OF THE CWFA. RADAR IMAGERY
SHOWS LIGHT SHOWERS SCATTERED ACROSS THE CWFA AHEAD OF THIS
FRONT...ESPECIALLY ALONG AND SOUTHEAST OF THE NATCHEZ TRACE
CORRIDOR. THIS FRONT IS EXPECTED TO MOVE THROUGH THE ARKLAMISS
REGION THIS MORNING...REACHING THE NATCHEZ TRACE BY 12Z AND LEAVING
THE SOUTHEASTERN PORTIONS OF THE CWFA BY 18Z TODAY. ALL RAIN SHOULD
MOVE OUT OF THE CWFA BY THIS AFTERNOON AND HAVE PRETTY MUCH REMAINED
WITH GUI FOR POPS TODAY. THE ONLY EXCEPTION IS IN THE EXTREME
SOUTHEAST INCLUDING HBG WHERE POPS WERE RAISED DUE TO HIGHER
CONFIDENCE THAT THE SITE WILL MEASURE. INSTABILITY REMAINS QUITE
LIMITED WITH THIS SYSTEM...AND DO NOT EXPECT ANYTHING MORE THAN
LIGHT SHOWERS AS THIS FRONT MOVES THROUGH.
TEMPERATURES WILL BE A LITTLE WARMER TODAY...ESPECIALLY ACROSS THE
SOUTH WHERE MORE WARMING WILL BE POSSIBLE AHEAD OF THE FRONT. DRIER
AND COOLER AIR WILL BEGIN TO MOVE INTO THE REGION OVERNIGHT.
HOWEVER WINDS AND CLOUD COVER WILL PREVENT TEMPERATURES FROM
DROPPING TOO MUCH. THE EXTREME NORTHERN FRINGES OF THE CWFA MAY
APPROACHING FREEZING WITH THE LOWER HALF OF THE CWFA ONLY DROP TO
THE MIDDLE TO UPPER 30S. ON MONDAY TEMPERATURES WILL BE A LITTLE
COOLER WITH UPPER 40S POSSIBLE IN THE NORTH RANGING TO THE MIDDLE TO
UPPER 50S IN THE SOUTH. OVERALL HAVE REMAINED RATHER CLOSE TO GUI
FOR TEMPERATURES THROUGH THE NEXT COUPLE OF DAYS./14/
.LONG TERM...THE MED RANGE/LONG TERM PORTION OF THE FORECAST
REMAINS DOMINATED BY COLD FIRST THEN WARMER WITH A FEW QUESTION
MARKS THROWN IN FOR THE LAST COUPLE PERIODS. TONIGHTS RUN OF MODELS
SHOW MUCH BETTER AGREEMENT WITH THE GFS NOW IN LINE WITH THE EURO
AND NAM MODELS. TUE-WED WILL BE RATHER CHILLY AS THE PATTERN WILL BE
DOMINATED BY A DEEP/LARGE LONG WAVE TROUGH ACROSS THE E CONUS.
THINGS BECOME MORE ZONAL BY THU/FRI AND WE SHOULD SEE A SOME KIND OF
S/W MOVE ACROSS THE AREA FRI INTO SAT.
MON NIGHT HAS MUCH MORE INTERESTING AS ALL GUID IS NOW SHOWING A
VERY INTENSE S/W DROP SOUTHWARD ON THE BACK SIDE OF THE LARGE
EASTERN TROUGH. THIS S/W WILL HAVE VERY LOW MID LEVEL HGTS WITH THE
NE PORTION OF THE CWA SEEING VALUES < 540M. THOSE ANOMALOUS HGTS ARE
SOME 2 TO 3.5 STANDARD DEVIATIONS BELOW CLIMO. ADDITIONALLY...MID
LEVEL WINDS WILL RANGE FROM 100-125KTS AT 500MB. THE CENTER OF THIS
S/W WILL BE VERY EFFICIENT AT SQUEEZING OUT ANY AVAILABLE MOISTURE
AND THE SEEMS TO BE DECENT LOW LEVEL MOISTURE ACROSS THE NE HALF OF
THE CWA BETWEEN MIDNIGHT AND NOON TUE. THE RESULT WILL BE -SN AND
FLURRIES GENERALLY FROM A GREENWOOD TO MERIDIAN LINE. BEST TIMING
FOR THIS WILL BE BETWEEN 3-9AM. AT THIS TIME...VERY LITTLE TO NO
ACCUM IS EXPECTED. HOWEVER...WE WILL HAVE TO KEEP A CLOSE EYE ON
THIS B/C IF GOOD MOISTURE CAN EXIST UP TO 700MB...THEN THERE WILL BE
A WINDOW OF TIME ACROSS THE NE COUPLE COUNTIES THAT EXPERIENCE
BETTER SNOW RATES. WITH THE WINDOW OF TIME BEING RATHER SHORT WHERE
THE DEEPEST MOISTURE MAY BE PRESENT...I WILL NOT CARRY -SN FOR TOO
LONG INTO THE TUE PERIOD. THERE DOES LOOK TO BE SUFFICIENT LOW LEVEL
MOISTURE TO KEEP A DECENT STRATO CU DECK AROUND...ESPECIALLY ACROSS
THE E HALF. ADDITIONALLY...STRONG CAA WILL BE OCCURRING AS THE
REGION WILL BE UNDER -3 TO -6C 925MB TEMPS. TEMPS AT 850MB WILL BE
RATHER CHILLY AS WELL AND RUN BETWEEN -6 AND -11C ON TUE. THESE
VALUES ARE SOME 2 TO 3 STANDARD DEVIATIONS BELOW CLIMO VALUES. GUID
HIGH TEMPS ARE MUCH COOLER THAN PREV RUNS AND I HAVE EVEN CUT A FEW
MORE...ESPECIALLY NE/E TO FIT THE LONGER DURATION OF LOW CLOUDS.
WITH THE S/W DEPARTING QUICKLY BY LATE AFTERNOON/EVENING...THE LOW
CLOUDS SHOULD DISSIPATE AS WELL FROM W-E BETWEEN 21-03Z. SFC HIGH
PRESSURE WILL SETTLE OVER THE CWA TUE N WITH THE CENTER LOCATED
BETWEEN I-20 AND I-10 BY 12Z WED. CLR SKIES AND CALM WINDS WILL
RESULT IN GREAT RAD COOLING CONDITIONS AND TEMPS WILL BOTTOM OUT IN
THE LOWER/MID 20S. BY AFTERNOON SW RETURN FLOW WILL SETUP AS THE SFC
HIGH SHIFTS A TAD TO THE E/SE. EVEN WITH THAT RETURN FLOW...THE COLD
START TO THE DAY WILL LIMIT HOW WARM WE WILL GET. THIS RUN OF THE
GUID IS COOLER THAN PREV RUNS AND HAVE FOLLOWED. LOWER TO MID 50S
LOOK GOOD.
THU/FRI WILL TRANSITION TO WARMER AS RETURN FLOW BECOME MORE
ENTRENCHED. EVEN WITH A COUPLE PERIODS OF RETURN FLOW...IT MAY TAKE
A WHILE TO GET DECENT MOISTURE BACK INTO THE AREA AS THE SFC HIGH
WILL SCOUR THE GULF PRETTY GOOD. GUID IS STILL TRYING HAVE LOWS ON
THE WARM SIDE TOO QUICKLY AND HAVE CONTINUED THE TREND OF LOWER THEM
BOTH THU/FRI MORNINGS. COLD GROUND...DRY AIR AND THE LINGERING SFC
RIDGE AXIS SHOULD ALLOW FOR THAT SETUP.
THERE IS SOME TIMING ISSUES FOR THE NEXT FRONT WITH THE GFS FASTER
THAN THE EURO. I LIKE SOMETHING IN BETWEEN WITH THE FRONT AND THE
NEXT RAIN CHANCES TO COME IN BY FRI INTO FRI EVENING. I WILL HOLD
ONTO THE LINGERING 20% THROUGH THE WEEKEND AS THERE REMAINS MANY
QUESTION MARKS ON IF THERE WILL BE A QUICK MOISTURE RETURN BY SAT AS
A DETACHED S/W OVER THE SW MAY MOVE OVER THE AREA. THIS FRI-SUN
PERIOD WILL LIKELY CONTINUE TO HAVE TIMING ISSUES SO IT MAY TAKE A
BIT LONGER TO GET THOSE PERIODS FIGURED OUT. /CME/
&&
.AVIATION...SKIES HAVE CLEARED AT ALL TAF SITES IN THE WAKE OF THIS
MORNING`S COLD FRONT PASSAGE. THEREFORE...VFR CONDITIONS ARE
EXPECTED TO PREVAIL AT ALL SITES THIS AFTERNOON AND EVENING...AS
WELL AS THROUGH THE OVERNIGHT HOURS TONIGHT.
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
14/CME
03/19
000
FXUS64 KJAN 181002
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
402 AM CST SUN JAN 18 2009
.SHORT TERM...SURFACE ANALYSIS THIS MORNING SHOWS THE APPROACHING
COLD FRONT STRETCHED ACROSS SOUTHEAST ARKANSAS ALONG THE FRINGES OF
THE CWFA. RADAR IMAGERY SHOWS LIGHT SHOWERS SCATTERED ACROSS THE
CWFA AHEAD OF THIS FRONT...ESPECIALLY ALONG AND SOUTHEAST OF THE
NATCHEZ TRACE CORRIDOR. THIS FRONT IS EXPECTED TO MOVE THROUGH THE
ARKLAMISS REGION THIS MORNING...REACHING THE NATCHEZ TRACE BY 12Z
AND LEAVING THE SOUTHEASTERN PORTIONS OF THE CWFA BY 18Z TODAY. ALL
RAIN SHOULD MOVE OUT OF THE CWFA BY THIS AFTERNOON AND HAVE PRETTY
MUCH REMAINED WITH GUI FOR POPS TODAY. THE ONLY EXCEPTION IS IN THE
EXTREME SOUTHEAST INCLUDING HBG WHERE POPS WERE RAISED DUE TO HIGHER
CONFIDENCE THAT THE SITE WILL MEASURE. INSTABILITY REMAINS QUITE
LIMITED WITH THIS SYSTEM...AND DO NOT EXPECT ANYTHING MORE THAN
LIGHT SHOWERS AS THIS FRONT MOVES THROUGH.
TEMPERATURES WILL BE A LITTLE WARMER TODAY...ESPECIALLY ACROSS THE
SOUTH WHERE MORE WARMING WILL BE POSSIBLE AHEAD OF THE FRONT. DRIER
AND COOLER AIR WILL BEGIN TO MOVE INTO THE REGION OVERNIGHT.
HOWEVER WINDS AND CLOUD COVER WILL PREVENT TEMPERATURES FROM
DROPPING TOO MUCH. THE EXTREME NORTHERN FRINGES OF THE CWFA MAY
APPROACHING FREEZING WITH THE LOWER HALF OF THE CWFA ONLY DROP TO
THE MIDDLE TO UPPER 30S. ON MONDAY TEMPERATURES WILL BE A LITTLE
COOLER WITH UPPER 40S POSSIBLE IN THE NORTH RANGING TO THE MIDDLE TO
UPPER 50S IN THE SOUTH. OVERALL HAVE REMAINED RATHER CLOSE TO GUI
FOR TEMPERATURES THROUGH THE NEXT COUPLE OF DAYS./14/
.LONG TERM...THE MED RANGE/LONG TERM PORTION OF THE FORECAST
REMAINS DOMINATED BY COLD FIRST THEN WARMER WITH A FEW QUESTION
MARKS THROWN IN FOR THE LAST COUPLE PERIODS. TONIGHTS RUN OF MODELS
SHOW MUCH BETTER AGREEMENT WITH THE GFS NOW IN LINE WITH THE EURO
AND NAM MODELS. TUE-WED WILL BE RATHER CHILLY AS THE PATTERN WILL BE
DOMINATED BY A DEEP/LARGE LONG WAVE TROUGH ACROSS THE E CONUS.
THINGS BECOME MORE ZONAL BY THU/FRI AND WE SHOULD SEE A SOME KIND OF
S/W MOVE ACROSS THE AREA FRI INTO SAT.
MON NIGHT HAS MUCH MORE INTERESTING AS ALL GUID IS NOW SHOWING A
VERY INTENSE S/W DROP SOUTHWARD ON THE BACK SIDE OF THE LARGE
EASTERN TROUGH. THIS S/W WILL HAVE VERY LOW MID LEVEL HGTS WITH THE
NE PORTION OF THE CWA SEEING VALUES < 540M. THOSE ANOMALOUS HGTS ARE
SOME 2 TO 3.5 STANDARD DEVIATIONS BELOW CLIMO. ADDITIONALLY...MID
LEVEL WINDS WILL RANGE FROM 100-125KTS AT 500MB. THE CENTER OF THIS
S/W WILL BE VERY EFFICIENT AT SQUEEZING OUT ANY AVAILABLE MOISTURE
AND THE SEEMS TO BE DECENT LOW LEVEL MOISTURE ACROSS THE NE HALF OF
THE CWA BETWEEN MIDNIGHT AND NOON TUE. THE RESULT WILL BE -SN AND
FLURRIES GENERALLY FROM A GREENWOOD TO MERIDIAN LINE. BEST TIMING
FOR THIS WILL BE BETWEEN 3-9AM. AT THIS TIME...VERY LITTLE TO NO
ACCUM IS EXPECTED. HOWEVER...WE WILL HAVE TO KEEP A CLOSE EYE ON
THIS B/C IF GOOD MOISTURE CAN EXIST UP TO 700MB...THEN THERE WILL BE
A WINDOW OF TIME ACROSS THE NE COUPLE COUNTIES THAT EXPERIENCE
BETTER SNOW RATES. WITH THE WINDOW OF TIME BEING RATHER SHORT WHERE
THE DEEPEST MOISTURE MAY BE PRESENT...I WILL NOT CARRY -SN FOR TOO
LONG INTO THE TUE PERIOD. THERE DOES LOOK TO BE SUFFICIENT LOW LEVEL
MOISTURE TO KEEP A DECENT STRATO CU DECK AROUND...ESPECIALLY ACROSS
THE E HALF. ADDITIONALLY...STRONG CAA WILL BE OCCURRING AS THE
REGION WILL BE UNDER -3 TO -6C 925MB TEMPS. TEMPS AT 850MB WILL BE
RATHER CHILLY AS WELL AND RUN BETWEEN -6 AND -11C ON TUE. THESE
VALUES ARE SOME 2 TO 3 STANDARD DEVIATIONS BELOW CLIMO VALUES. GUID
HIGH TEMPS ARE MUCH COOLER THAN PREV RUNS AND I HAVE EVEN CUT A FEW
MORE...ESPECIALLY NE/E TO FIT THE LONGER DURATION OF LOW CLOUDS.
WITH THE S/W DEPARTING QUICKLY BY LATE AFTERNOON/EVENING...THE LOW
CLOUDS SHOULD DISSIPATE AS WELL FROM W-E BETWEEN 21-03Z. SFC HIGH
PRESSURE WILL SETTLE OVER THE CWA TUE N WITH THE CENTER LOCATED
BETWEEN I-20 AND I-10 BY 12Z WED. CLR SKIES AND CALM WINDS WILL
RESULT IN GREAT RAD COOLING CONDITIONS AND TEMPS WILL BOTTOM OUT IN
THE LOWER/MID 20S. BY AFTERNOON SW RETURN FLOW WILL SETUP AS THE SFC
HIGH SHIFTS A TAD TO THE E/SE. EVEN WITH THAT RETURN FLOW...THE COLD
START TO THE DAY WILL LIMIT HOW WARM WE WILL GET. THIS RUN OF THE
GUID IS COOLER THAN PREV RUNS AND HAVE FOLLOWED. LOWER TO MID 50S
LOOK GOOD.
THU/FRI WILL TRANSITION TO WARMER AS RETURN FLOW BECOME MORE
ENTRENCHED. EVEN WITH A COUPLE PERIODS OF RETURN FLOW...IT MAY TAKE
A WHILE TO GET DECENT MOISTURE BACK INTO THE AREA AS THE SFC HIGH
WILL SCOUR THE GULF PRETTY GOOD. GUID IS STILL TRYING HAVE LOWS ON
THE WARM SIDE TOO QUICKLY AND HAVE CONTINUED THE TREND OF LOWER THEM
BOTH THU/FRI MORNINGS. COLD GROUND...DRY AIR AND THE LINGERING SFC
RIDGE AXIS SHOULD ALLOW FOR THAT SETUP.
THERE IS SOME TIMING ISSUES FOR THE NEXT FRONT WITH THE GFS FASTER
THAN THE EURO. I LIKE SOMETHING IN BETWEEN WITH THE FRONT AND THE
NEXT RAIN CHANCES TO COME IN BY FRI INTO FRI EVENING. I WILL HOLD
ONTO THE LINGERING 20% THROUGH THE WEEKEND AS THERE REMAINS MANY
QUESTION MARKS ON IF THERE WILL BE A QUICK MOISTURE RETURN BY SAT AS
A DETACHED S/W OVER THE SW MAY MOVE OVER THE AREA. THIS FRI-SUN
PERIOD WILL LIKELY CONTINUE TO HAVE TIMING ISSUES SO IT MAY TAKE A
BIT LONGER TO GET THOSE PERIODS FIGURED OUT. /CME/
&&
.AVIATION...FLIGHT CATEGORIES WILL BECOME MVFR DUE TO LOWERING
CEILINGS EARLY THIS MORNING. SITES ACROSS THE NORTHWEST HAVE
ALREADY BEGUN SEEING THESE LOWERED CEILINGS. PERIODS OF IFR
CEILINGS CAN NOT BE RULED OUT OVER MAINLY THE SOUTHEASTERN PORTIONS
OF THE AREA. CONDITIONS WILL BEGIN TO IMPROVE FROM NORTHWEST TO
SOUTHEAST...BEGINNING IN THE NORTHWEST AS EARLY AS SUNRISE...AND
IMPROVING IN THE SOUTHEAST BY AROUND LUNCHTIME TO EARLY AFTERNOON.
IN ADDITION TO LOW CEILINGS...SHOWERS WILL CONTINUE OVER THE AREA
THROUGH THE MORNING AS A COLD FRONT MOVES THROUGH THE REGION. THE
COLD FRONT SHOULD REACH THE NATCHEZ TRACE CORRIDOR BY AROUND SUNRISE
AND SHOULD LEAVE THE SOUTHEASTERN PART OF THE REGION BY AROUND
LUNCHTIME. AFTER THIS FRONT MOVES THROUGH...VFR FLIGHT CATEGORIES
SHOULD TAKE OVER THROUGH THE REMAINDER OF THE FORECAST PERIOD./14/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 59 37 51 32 / 11 0 6 1
MERIDIAN 59 36 49 29 / 24 0 3 8
VICKSBURG 60 36 52 32 / 3 0 9 0
HATTIESBURG 65 40 57 31 / 29 0 5 3
NATCHEZ 61 38 54 32 / 4 0 9 0
GREENVILLE 57 36 47 30 / 5 0 6 5
GREENWOOD 55 34 51 29 / 6 0 5 9
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
14/CME
000
FXUS64 KJAN 180405
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
955 PM CST SAT JAN 17 2009
.UPDATE...UPDATED FORECAST EARLIER TO LOWER RAIN CHANCES PRIOR TO
MIDNIGHT AND ADJUST TEMPERATURES. COLD FRONT STILL WEST OF LITTLE
ROCK AND SHOULD NOT MOVE INTO DELTA UNTIL AFTER MIDNIGHT. REGIONAL
RADARS STILL NOT SHOWING MUCH PRECIPITATION ALONG AND AHEAD OF THE
FRONT IN OUR REGION. CLOUD COVER AND CONTINUED WAA AHEAD OF COLD
FRONT HAS HELPED TEMPERATURES WARM UP IN THE NORTHEAST FROM THE
AFTERNOON AND DROP OFF ONLY SLIGHTLY ELSEWHERE. DEW POINTS WERE
RUNNING GREATER THAN EXPECTED AS WELL. WITH THE COLD FRONT MOVING
INTO THE CWFA A LITTLE SLOWER HAVE INCREASED MIN TEMP FORECAST
SEVERAL DEGREES IN THE NORTHEAST. MODELS STILL INDICATE DECENT
COVERAGE OF RAIN AHEAD OF THE FRONT AFTER MIDNIGHT SO AM RELUCTANT
TO LOWER GOOD CHANCE TO LIKELY POPS THAT WERE BEING CARRIED. UPDATED
GRIDS AND FORECASTS HAVE BEEN POSTED. /22/
.PREVIOUS DISCUSSION...SHORT TERM...THE AIR MASS CONTINUES TO WARM
AND GRADUALLY MOISTEN AHEAD OF THE APPROACHING COLD FRONT. NERN
ZONES REMAIN THE COOLEST AND AFTERNOON DEW POINTS REMAINED IN THE
TEENS BUT WE WILL SEE ENOUGH MODERATION TO PREVENT THE POSSIBILITY
OF ANY WINTERY MIX WHEN PRECIP RESUMES THIS EVENING. THE WEAK
BOUNDARY WILL DROP INTO THE NW CORNER OF MS AROUND MIDNIGHT BUT
ASSOCIATED MOISTURE WILL BE SHALLOW...NOT QUITE TO 700 MBS.
ISENTROPIC LIFT WILL INCREASE FROM THE NORTH TONIGHT AND SPREAD SWD.
THE BOUNDARY DROPS ACROSS THE REGION WITH NWLY LOW LEVEL ACROSS THE
FORECAST AREA BY 18Z SUNDAY. CLOUD COVER WILL DECREASE FROM THE
NORTH TOMORROW BUT SEVERAL DRY WAVES WILL DROP THIS WAY IN NWLY
FLOW...MAINTAINING OCCASIONAL PERIODS OF CLOUD COVER OVER THE REGION
SUN NIGHT THROUGH MON NIGHT.
LOWERED MINS OVER NERN ZONES SLIGHTLY CONSIDERING AFTERNOON
TEMPERATURES HAVE REBOUNDED BELOW THE CURVE. OTHERWISE FOLLOWED THE
LATEST MOS TREND FOR WARMER TEMPERATURES SUNDAY PER LATEST
OBSERVATIONS UPSTREAM AND SUNDAY NIGHT AS MOISTURE ACCOMPANIES THE
NEXT WAVE. WILL UNDERCUT MOS FOR MONDAY AND MONDAY NIGHT...LEAVING
PREVIOUS COOLER FORECAST INTACT. MOS DOES NOT REFLECT THE HEALTHY
COLD AIR ADVECTION INDICATED AT 850 MB MONDAY AND MONDAY NIGHT.
LONG TERM...THE MED RANGE/LONG TERM PORTION OF THIS FORECAST CAN BE
DIVIDED BASICALLY IN HALF. THE FIRST HALF (TUE-WED) WILL BE
DOMINATED BY A LARGE/DEEP EASTERN CONUS TROUGH AND BELOW NORMAL
TEMPS. THE LATTER HALF WILL SEE A TRANSITION IN THE PATTERN WITH
RETURN FLOW FOR THU/FRI AND THEN A FRONTAL PASSAGE SOMETIME BETWEEN
LATE FRI AND SAT.
FOR TUE...WHILE OUR REGION REMAINS ON THE BACK SIDE OF THE LARGE
EASTERN TROUGH...DEEP NW/N FLOW WILL DOMINATE AND THE AREA WILL SEE
A FEW SURGES OF COLD AIR. THERE ARE DIFFERENCES IN THE TIMING OF
THESE SURGES BETWEEN THE EURO AND GFS. HOWEVER...I WILL FOLLOW THE
EURO AS IT HAS SUPPORT FROM THE NAM AND SREF WHICH ALL HAVE BEEN
PERFORMING BETTER OF LATE. THE EURO/NAM ARE PUSHING IN A MUCH COOLER
AIRMASS FOR MON AFTERNOON AND LINGERING IT TILL WED MORNING. I WILL
LEAN HEAVILY ON THE EURO/NAM SOLUTION AND CUT HIGHS TUE AS CAA AND
NEG LOW LEVEL TEMPS WILL EXIST. I WAS MORE CONSERVATIVE IN THE W AND
ONLY CUT 1-2 DEGREES. THE E HALF WILL BE COOLER AND HAVE CUT 3-5
DEGREES.
WED WILL BE A TRANSITION DAY...MORNING LOWS WILL BE QUITE CHILLY AS
THE SFC RIDGE LINGERS ACROSS THE CWA. DRY AIR AND LIGHT/CALM WINDS
WILL ALLOW FOR ANOTHER NIGHT WITH LOWS 25-30 DEGREES. RETURN FLOW
WILL SETUP BY AFTERNOON AS THE SFC HIGH SHIFTS EAST. LOOK FOR A
SOLID WARM UP...BUT WITH SUCH A COLD START...WIDESPREAD UPPER 50S
WILL BE TOUGH TO ACHIEVE. MID 50S WILL BE THE MEDIAN WITH COOLER
READINGS E AND WARMER WEST.
FOR THU/FRI...RETURN FLOW WILL SETUP AHEAD OF A TROUGH/ASSOCIATED
FRONT WHICH LOOKS TO MOVE THROUGH LATE FRI INTO EARLY SAT. THERE
WILL BE SOME LINGERING EFFECTS OF THE LINGERING SFC RIDGE AXIS AND
LOW LEVEL DRY AIR WILL BE SLOW TO LET UP ITS GRIP. ADD IN COLD
GROUND CONDITIONS AND I BELIEVE GUID IS TRYING TO WARM UP LOWS TO
QUICKLY. I WILL CUT 2-4 DEGREES OFF THU/FRI MORNING LOWS. AS FOR
HIGHS WARMER LOW LEVEL TEMPS MOVE IN FOR THU AFTERNOON AND WITH DRY
AIR IN PLACE AND FULL SUNSHINE...HIGH TEMPS SHOULD BREAK 60 DEGREES
FOR THE FIRST TIME SINCE JAN 10TH. GUID HIGHS SEEMED A TAD LOW IN A
FEW LOCATIONS AND I ADJ UPWARD A FEW DEGREES. FOR FRI...EVEN WARMER
LOW LEVEL TEMPS WILL SPREAD OVER THE AREA AHEAD OF THE SFC FRONT.
GUID WAS IN THE 60S...BUT I ADJ UPWARD A FEW MORE DEGREES TO BETTER
MATCH CLIMO WITH THE ASSOCIATED LOW LEVEL TEMPS.
AS FOR PRECIP CHANCES...VERY LOW PROBABILITIES WILL EXIST FOR MOST
OF THE EXTENDED. BETTER MOISTURE...ALONG WITH LIFT...COME AT THE END
OF THE PERIOD WITH THE TROUGH/FRONTAL PASSAGE LATE FRI INTO SAT.
GUID POPS SEEMED REASONABLE AND HAVE FOLLOWED. /CME/
&&
.AVIATION...UPDATED...VFR CONDITIONS PREVAIL THIS EVENING WITH
CEILINGS AROUND 7KFT. STILL EXPECTING CEILINGS TO GRADUALLY LOWER TO
MVFR AND THEN TO IFR REMAINDER OF NIGHT AHEAD OF APPROACHING COLD
FRONT. COLD FRONT LOOKS A LITTLE SLOWER AND STILL WITH NO
PRECIPITATION ALONG IT CLOSE TO OUR REGION. THE COLD FRONT AND LIGHT
RAIN SHOULD BE ENTERING WESTERN PORTIONS OF THE AREA BY 07Z SUN AND
BE NEAR JAN BY 12Z. THE RAIN WILL CONTINUE ALONG AND AHEAD OF THE
COLD FRONT SUNDAY THAT WILL NOT PUSH SOUTH OF HBG UNTIL AFTER 18Z.
CONDITIONS WILL IMPROVE FROM THE WEST BEHIND THE COLD FRONT. /22/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 41 57 35 48 / 64 23 4 3
MERIDIAN 39 55 32 48 / 71 37 4 6
VICKSBURG 43 58 36 50 / 53 13 5 6
HATTIESBURG 44 62 36 52 / 48 48 4 7
NATCHEZ 46 59 38 50 / 55 17 4 4
GREENVILLE 37 53 34 45 / 38 8 7 7
GREENWOOD 37 52 33 45 / 46 11 5 4
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
03/CME/19
000
FXUS64 KJAN 172134
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
335 PM CST SAT JAN 17 2009
.SHORT TERM...THE AIR MASS CONTINUES TO WARM AND GRADUALLY MOISTEN
AHEAD OF THE APPROACHING COLD FRONT. NERN ZONES REMAIN THE COOLEST
AND AFTERNOON DEW POINTS REMAINED IN THE TEENS BUT WE WILL SEE
ENOUGH MODERATION TO PREVENT THE POSSIBILITY OF ANY WINTERY MIX WHEN
PRECIP RESUMES THIS EVENING. THE WEAK BOUNDARY WILL DROP INTO THE NW
CORNER OF MS AROUND MIDNIGHT BUT ASSOCIATED MOISTURE WILL BE
SHALLOW...NOT QUITE TO 700 MBS. ISENTROPIC LIFT WILL INCREASE FROM
THE NORTH TONIGHT AND SPREAD SWD. THE BOUNDARY DROPS ACROSS THE
REGION WITH NWLY LOW LEVEL ACROSS THE FORECAST AREA BY 18Z SUNDAY.
CLOUD COVER WILL DECREASE FROM THE NORTH TOMORROW BUT SEVERAL DRY
WAVES WILL DROP THIS WAY IN NWLY FLOW...MAINTAINING OCCASIONAL
PERIODS OF CLOUD COVER OVER THE REGION SUN NIGHT THROUGH MON NIGHT.
LOWERED MINS OVER NERN ZONES SLIGHTLY CONSIDERING AFTERNOON
TEMPERATURES HAVE REBOUNDED BELOW THE CURVE. OTHERWISE FOLLOWED THE
LATEST MOS TREND FOR WARMER TEMPERATURES SUNDAY PER LATEST
OBSERVATIONS UPSTREAM AND SUNDAY NIGHT AS MOISTURE ACCOMPANIES THE
NEXT WAVE. WILL UNDERCUT MOS FOR MONDAY AND MONDAY NIGHT...LEAVING
PREVIOUS COOLER FORECAST INTACT. MOS DOES NOT REFLECT THE HEALTHY
COLD AIR ADVECTION INDICATED AT 850 MB MONDAY AND MONDAY NIGHT.
.LONG TERM...THE MED RANGE/LONG TERM PORTION OF THIS FORECAST CAN
BE DIVIDED BASICALLY IN HALF. THE FIRST HALF (TUE-WED) WILL BE
DOMINATED BY A LARGE/DEEP EASTERN CONUS TROUGH AND BELOW NORMAL
TEMPS. THE LATTER HALF WILL SEE A TRANSITION IN THE PATTERN WITH
RETURN FLOW FOR THU/FRI AND THEN A FRONTAL PASSAGE SOMETIME BETWEEN
LATE FRI AND SAT.
FOR TUE...WHILE OUR REGION REMAINS ON THE BACK SIDE OF THE LARGE
EASTERN TROUGH...DEEP NW/N FLOW WILL DOMINATE AND THE AREA WILL SEE
A FEW SURGES OF COLD AIR. THERE ARE DIFFERENCES IN THE TIMING OF
THESE SURGES BETWEEN THE EURO AND GFS. HOWEVER...I WILL FOLLOW THE
EURO AS IT HAS SUPPORT FROM THE NAM AND SREF WHICH ALL HAVE BEEN
PERFORMING BETTER OF LATE. THE EURO/NAM ARE PUSHING IN A MUCH COOLER
AIRMASS FOR MON AFTERNOON AND LINGERING IT TILL WED MORNING. I WILL
LEAN HEAVILY ON THE EURO/NAM SOLUTION AND CUT HIGHS TUE AS CAA AND
NEG LOW LEVEL TEMPS WILL EXIST. I WAS MORE CONSERVATIVE IN THE W AND
ONLY CUT 1-2 DEGREES. THE E HALF WILL BE COOLER AND HAVE CUT 3-5
DEGREES.
WED WILL BE A TRANSITION DAY...MORNING LOWS WILL BE QUITE CHILLY AS
THE SFC RIDGE LINGERS ACROSS THE CWA. DRY AIR AND LIGHT/CALM WINDS
WILL ALLOW FOR ANOTHER NIGHT WITH LOWS 25-30 DEGREES. RETURN FLOW
WILL SETUP BY AFTERNOON AS THE SFC HIGH SHIFTS EAST. LOOK FOR A
SOLID WARM UP...BUT WITH SUCH A COLD START...WIDESPREAD UPPER 50S
WILL BE TOUGH TO ACHIEVE. MID 50S WILL BE THE MEDIAN WITH COOLER
READINGS E AND WARMER WEST.
FOR THU/FRI...RETURN FLOW WILL SETUP AHEAD OF A TROUGH/ASSOCIATED
FRONT WHICH LOOKS TO MOVE THROUGH LATE FRI INTO EARLY SAT. THERE
WILL BE SOME LINGERING EFFECTS OF THE LINGERING SFC RIDGE AXIS AND
LOW LEVEL DRY AIR WILL BE SLOW TO LET UP ITS GRIP. ADD IN COLD
GROUND CONDITIONS AND I BELIEVE GUID IS TRYING TO WARM UP LOWS TO
QUICKLY. I WILL CUT 2-4 DEGREES OFF THU/FRI MORNING LOWS. AS FOR
HIGHS WARMER LOW LEVEL TEMPS MOVE IN FOR THU AFTERNOON AND WITH DRY
AIR IN PLACE AND FULL SUNSHINE...HIGH TEMPS SHOULD BREAK 60 DEGREES
FOR THE FIRST TIME SINCE JAN 10TH. GUID HIGHS SEEMED A TAD LOW IN A
FEW LOCATIONS AND I ADJ UPWARD A FEW DEGREES. FOR FRI...EVEN WARMER
LOW LEVEL TEMPS WILL SPREAD OVER THE AREA AHEAD OF THE SFC FRONT.
GUID WAS IN THE 60S...BUT I ADJ UPWARD A FEW MORE DEGREES TO BETTER
MATCH CLIMO WITH THE ASSOCIATED LOW LEVEL TEMPS.
AS FOR PRECIP CHANCES...VERY LOW PROBABILITIES WILL EXIST FOR MOST
OF THE EXTENDED. BETTER MOISTURE...ALONG WITH LIFT...COME AT THE END
OF THE PERIOD WITH THE TROUGH/FRONTAL PASSAGE LATE FRI INTO SAT.
GUID POPS SEEMED REASONABLE AND HAVE FOLLOWED. /CME/
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL INTO LATE AFTERNOON.
HOWEVER...AS LOW LEVEL MOISTURE AND CLOUDS CONTINUE TO INCREASE THIS
EVENING AHEAD OF AN APPROACHING COLD FRONT...CEILINGS WILL LOWER TO
MVFR STATUS EVERYWHERE...AND REMAIN THERE THROUGH THE NIGHT AND INTO
EARLY SUNDAY MORNING. IN ADDITION TO THE LOWERED CEILINGS...SHOWERS
WILL ALSO BEGIN DEVELOPING LATE THIS EVENING AND PERSIST THROUGH THE
OVERNIGHT HOURS AND INTO SUNDAY MORNING. AS THE FRONT TRAVERSES THE
REGION SUNDAY MORNING...LOOK FOR CONDITIONS TO IMPROVE FROM
NORTHWEST TO SOUTHEAST THROUGH SUNDAY AFTERNOON. /19/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 41 57 35 48 / 64 23 4 3
MERIDIAN 39 55 32 48 / 71 37 4 6
VICKSBURG 43 58 36 50 / 53 13 5 6
HATTIESBURG 44 62 36 52 / 48 48 4 7
NATCHEZ 46 59 38 50 / 55 17 4 4
GREENVILLE 37 53 34 45 / 38 8 7 7
GREENWOOD 37 52 33 45 / 46 11 5 4
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
03/CME/19
000
FXUS64 KJAN 171733
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
1132 AM CST SAT JAN 17 2009
.UPDATE...LOWERED NERN ZONES HIGHS TO UPPER 30S AND LOWER 40S. ALSO
REMOVED MENTION OF SLEET. CBM REPORTING LIGHT RAIN AND WARMING ABOVE
FREEZING.
&&
.DISCUSSION...DEVELOPING WARM AIR ADVECTION HAS RESULTED IN AREAS OF
VERY LIGHT PRECIP THIS MORNING. LIGHT SPRINKLES WILL BE POSSIBLE
OVER THE REGION. HAVE UPDATED THE FORECAST TO REFLECT POSSIBILITY
OF VERY LIGHT SLEET OR A FEW FLURRIES WHEN PRECIP INITIALLY MOVES
INTO AREAS IN THE EAST. AS THE DRY AIR MASS MOISTENS...THE CHANCE OF
LIGHT SLEET OR LIGHT FLURRIES WILL END LEAVING A FEW SPRINKLES OVER
THE AREA. DEWPOINTS WILL INCREASE FROM THE WEST TODAY BUT AT A
SLIGHTLY SLOWER RATE AND HAVE ADJUSTED DEWPOINTS A LITTLE COOLER FOR
THE AFTERNOON.
&&
.PREV DISCUSSION...420 AM CST SAT JAN 17 2009 A SLIGHT WARM UP CAN
BE EXPECTED FOR THE ARKLAMISS REGION THIS WEEKEND. SURFACE ANALYSIS
THIS MORNING SHOWS HIGH PRESSURE CENTERED OVER THE EASTERN THIRD OF
THE CWFA AND INTO AL. THIS HAS PUT THE WESTERN HALF OF THE CWFA
UNDER WEAK RETURN FLOW EARLY THIS MORNING. CLOUDS THAT HAVE MOVED
OVER THE CWFA THIS MORNING IS PREVENTING TEMPERATURES FROM DROPPING
TOO MUCH THIS MORNING. IN FACT...TEMPERATURES ARE GENERALLY
REMAINING IN THE MIDDLE 50S OR WARMER. AS A RESULT THE REMAINDER OF
THE HARD FREEZE WARNING HAS BEEN CANCELED THIS MORNING.
THE AREA WILL REMAIN DRY TODAY BUT WILL CONTINUE TO SEE AN INCREASE
IN CLOUD COVER AS MOISTURE INCREASES AHEAD OF OUR NEXT APPROACHING
FRONT. A SHORTWAVE IS EXPECTED TO MOVE AROUND THE BASE OF THE
TROUGH OVER THE EASTERN CONUS. THIS WILL BRING A COLD FRONT THROUGH
THE ARKLAMISS REGION TONIGHT INTO SUNDAY. HAVE KEPT THUNDER WORDING
OUT OF THE WX FOR THIS FRONT WITH VERY LIMITED INSTABILITY
EXPECTED. THE RAIN IS EXPECTED TO MOVE OUT OF THE SOUTHEASTERN
PORTIONS OF THE CWFA BY SUNDAY EVENING. SURFACE HIGH PRESSURE WILL
MOVE IN BEHIND THE FRONT TO KEEP THE AREA DRY FOR SUNDAY EVENING
THROUGH SUNDAY NIGHT.
TEMPERATURES WILL STILL BE A LITTLE ON THE COOL SIDE TODAY AS CLOUD
COVER WILL NOT ALLOW FOR TOO MUCH WARMING. TEMPERATURES TODAY ARE
EXPECTED TO BE IN THE UPPER 40S TO LOWER 50S. TEMPERATURES WILL BE
MUCH WARMER TONIGHT THAN WE HAVE SEEN IN PREVIOUS NIGHTS AS RETURN
FLOW CONTINUES AHEAD OF THE FRONT. IN ADDITION...THERE WILL BE
PLENTY CLOUD COVER AND SHOWERS AROUND TO PREVENT COOLING OVERNIGHT.
ALL LOCATIONS SHOULD REMAIN ABOVE FREEZING TONIGHT. COOLER
TEMPERATURES WILL BEGIN TO CREEP BACK INTO THE AREA SUNDAY NIGHT
BEHIND THE FRONT WITH NEAR FREEZING TEMPERATURES EXPECTED AGAIN.
OVERALL HAVE REMAINED WITH GUI FOR TEMPERATURES THROUGH THE NEXT
COUPLE OF DAYS./14/
.LONG TERM...THE MED RANGE/LONG TERM PORTION OF THIS FORECAST CAN
BE DIVIDED BASICALLY IN HALF. THE FIRST HALF (MON-WED) WILL BE
DOMINATED BY A LARGE/DEEP EASTERN CONUS TROUGH AND BELOW NORMAL
TEMPS. THE LATTER HALF WILL SEE A TRANSITION IN THE PATTERN WITH
RETURN FLOW FOR THU/FRI AND THEN A FRONTAL PASSAGE SOMETIME BETWEEN
LATE FRI AND SAT.
FOR MON/TUE...WHILE OUR REGION REMAINS ON THE BACK SIDE OF THE LARGE
EASTERN TROUGH...DEEP NW/N FLOW WILL DOMINATE AND THE AREA WILL SEE
A FEW SURGES OF COLD AIR. THERE ARE DIFFERENCES IN THE TIMING OF
THESE SURGES BETWEEN THE EURO AND GFS. HOWEVER...I WILL FOLLOW THE
EURO AS IT HAS SUPPORT FROM THE NAM AND SREF WHICH ALL HAVE BEEN
PERFORMING BETTER OF LATE. I CAN SEE HIGHS MON BEING COOLER THAN IF
THE FRONT IS FASTER LIKE THE GFS IS SUGGESTING. HOWEVER...LEANING
TOWARD THE EURO AND NAM...I WILL GO WITH THE SLOWER
FRONT/REINFORCING AIRMASS. THERE LOOKS TO BE A VERY POTENT S/W
DROPPING S ON THE BACKSIDE OF THE LARGE UPPER TROUGH AND THIS
FEATURE WILL LIKELY BRING WITH IT A BRIEF RETURN FLOW OUT OF THE W
WHICH WILL KEEP LOW LEVEL TEMPS A TAD WARM TO START MON. KEEPING IN
MIND A FASTER FROPA IS POSSIBLE I WILL ONLY GO ABV GUID IN THE SE
CWA. ALL GUID BRINGS THE FRONT INTO THE NW/N CWA BY 15Z MON AND THAT
SHOULD KEEP TEMPS IN THE LOWER/MID 40S. AS A RESULT...WILL LOWER A
FEW LOCATIONS DOWN TOWARD THE MID 40S. THE MAIN ADJ WILL BE FOR MON
N WHERE THE 00Z GFS WAS WAY TOO WARM AS IT HAS A LOW LEVEL RETURN
FLOW FROM THE W SETTING UP. THE EURO/NAM ARE PUSHING IN A MUCH
COOLER AIRMASS FOR MON AFTERNOON AND LINGERING IT TILL WED MORNING.
I WILL LEAN HEAVILY ON THE EURO/NAM SOLUTION AND CUT LOWS QUITE A
BIT TO GET THE CWA BETWEEN 25-30 DEGREES. I HAVE ALSO CUT HIGHS TUE
AS CAA AND NEG LOW LEVEL TEMPS WILL EXIST. I WAS MORE CONSERVATIVE
IN THE W AND ONLY CUT 1-2 DEGREES. THE E HALF WILL BE COOLER AND
HAVE CUT 3-5 DEGREES.
WED WILL BE A TRANSITION DAY...MORNING LOWS WILL BE QUITE CHILLY AS
THE SFC RIDGE LINGERS ACROSS THE CWA. DRY AIR AND LIGHT/CALM WINDS
WILL ALLOW FOR ANOTHER NIGHT WITH LOWS 25-30 DEGREES. RETURN FLOW
WILL SETUP BY AFTERNOON AS THE SFC HIGH SHIFTS EAST. LOOK FOR A
SOLID WARM UP...BUT WITH SUCH A COLD START...WIDESPREAD UPPER 50S
WILL BE TOUGH TO ACHIEVE. MID 50S WILL BE THE MEDIAN WITH COOLER
READINGS E AND WARMER WEST.
FOR THU/FRI...RETURN FLOW WILL SETUP AHEAD OF A TROUGH/ASSOCIATED
FRONT WHICH LOOKS TO MOVE THROUGH LATE FRI INTO EARLY SAT. THERE
WILL BE SOME LINGERING EFFECTS OF THE LINGERING SFC RIDGE AXIS AND
LOW LEVEL DRY AIR WILL BE SLOW TO LET UP ITS GRIP. ADD IN COLD
GROUND CONDITIONS AND I BELIEVE GUID IS TRYING TO WARM UP LOWS TO
QUICKLY. I WILL CUT 2-4 DEGREES OFF THU/FRI MORNING LOWS. AS FOR
HIGHS WARMER LOW LEVEL TEMPS MOVE IN FOR THU AFTERNOON AND WITH DRY
AIR IN PLACE AND FULL SUNSHINE...HIGH TEMPS SHOULD BREAK 60 DEGREES
FOR THE FIRST TIME SINCE JAN 10TH. GUID HIGHS SEEMED A TAD LOW IN A
FEW LOCATIONS AND I ADJ UPWARD A FEW DEGREES. FOR FRI...EVEN WARMER
LOW LEVEL TEMPS WILL SPREAD OVER THE AREA AHEAD OF THE SFC FRONT.
GUID WAS IN THE 60S...BUT I ADJ UPWARD A FEW MORE DEGREES TO BETTER
MATCH CLIMO WITH THE ASSOCIATED LOW LEVEL TEMPS.
AS FOR PRECIP CHANCES...VERY LOW PROBABILITIES WILL EXIST FOR MOST
OF THE EXTENDED. BETTER MOISTURE...ALONG WITH LIFT...COME AT THE END
OF THE PERIOD WITH THE TROUGH/FRONTAL PASSAGE LATE FRI INTO SAT.
GUID POPS SEEMED REASONABLE AND HAVE FOLLOWED. /CME/
&&
.AVIATION...VFR FLIGHT CATEGORIES WILL PREVAIL TODAY AND INTO THIS
EVENING WITH GENERALLY OVERCAST DECKS FROM 3500-5000 FEET.
OCCASIONAL PERIODS OF SPRINKLES WILL OCCUR. PATCHY VERY LIGHT SLEET
WILL BE POSSIBLE IN THE EAST AT THE INITIAL ONSET OF PRECIP BUT THIS
WILL TURN TO ALL SPRINKLES SHORTLY AFTER PRECIP STARTS. CLOUDS WILL
LOWER AHEAD OF AN APPROACHING COLD FRONT THIS EVENING AND INTO THE
OVERNIGHT HOURS. THIS WILL GIVE PERIODS OF MVFR CEILINGS. IN
ADDITION THE AREA WILL BEGIN SEEING SHOWERS DURING THE EVENING HOURS
INTO THE OVERNIGHT...WHICH COULD ALSO LOWER FLIGHT CATEGORIES. THE
FRONT WHICH WILL BE PROVIDING THE LOWER CEILINGS AND SHOWERS TO THE
AREA IS EXPECTED TO MOVE OUT OF THE AREA SUNDAY AFTERNOON...TO GIVE
IMPROVING CONDITIONS FOR SUNDAY EVENING./14/
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
14/CME/03
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