FXUS64 KMEG 291041
AFDMEG
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEMPHIS TN
441 AM CST SUN NOV 29 2009
.DISCUSSION...
UNLIKE THE EXCEPTIONALLY DRY WEATHER THE MIDSOUTH HAS EXPERIENCED
FOR MUCH OF THE MONTH OF NOVEMBER...WE CAN EXPECT WET WEATHER AS THE
MONTH DRAWS TO AN END. EARLY THIS MORNING...A COLD FRONT STRETCHED
FROM NORTHERN MO ACROSS SOUTHEAST KS INTO CENTRAL OK. ISENTROPIC LIFT
WAS CAUSING LOW AND MID LEVEL CLOUDS TO SPREAD RAPIDLY INTO THE
MIDSOUTH FROM THE SOUTHWEST...AND VERY LIGHT RAIN HAD DEVELOPED
FROM NORTH MS INTO EAST-CENTRAL AR. SURFACE DEWPOINTS INCREASED
FROM MOSTLY THE 40S ACROSS THE MIDSOUTH TO THE UPPER 50S TO OUR
SOUTHWEST ACROSS NORTHEAST TX.
THE COLD FRONT WILL PUSH SOUTHEASTWARD TODAY...STRETCHING FROM
SOUTHEAST MO AND NORTHEAST AR INTO NORTHEAST TX BY SUNSET.
INCREASED THE POPS A LITTLE ACROSS THE AREA TODAY AS WARM AND
MOIST ADVECTION ALOFT CONTINUES AHEAD OF THE APPROACHING COLD
FRONT. MOST OF THE RAIN WILL BE LIGHT THIS MORNING AS THE LOWER
LEVELS OF THE ATMOSPHERE ARE BEGINNING RATHER DRY. HOWEVER...THINK
THE INTENSITY OF THE RAIN WILL BEGIN TO INCREASE THIS AFTERNOON
ESPECIALLY JUST ALONG AND AHEAD OF THE FRONT.
THE COLD FRONT IS FORECAST TO MOVE THROUGH THE MIDSOUTH TONIGHT
WITH WIDESPREAD SHOWERS. SOME WEAK ELEVATED INSTABILITY IS
INDICATED BUT ATTM THINK ANY THUNDERSTORMS IF ANY WILL BE VERY
ISOLATED AND WILL NOT MENTION IN THE FORECAST. BETWEEN 1/2 AND 3/4
INCH OF RAIN IS FORECAST IN MOST LOCATIONS.
SHOWERS WILL LINGER ACROSS PORTIONS OF NORTH MS MONDAY MORNING.
OTHERWISE...SURFACE HIGH PRESSURE WILL BUILD INTO THE AREA FROM
THE NORTH. MUCH COOLER AND DRIER AIR WILL SPREAD INTO THE REGION.
SKIES WILL CLEAR FROM THE NORTH AND ARE EXPECTED TO BE CLEAR
ACROSS THE ENTIRE MIDSOUTH BY MONDAY NIGHT. WILL NEED TO WATCH FOR
THE DEVELOPMENT OF FOG MONDAY NIGHT WITH LIGHT WINDS AND A WET GROUND.
TUESDAY...THE FIRST DAY OF DECEMBER...LOOKS TO BEGIN WITH NICE
WEATHER. WE WILL BE BETWEEN SYSTEMS WITH MOSTLY SUNNY SKIES AND
SEASONABLY COOL TEMPERATURES.
PREFERRED THE 00Z ECMWF MODEL FOR THE FORECAST IN THE MIDDLE AND
LATTER PART OF THIS WEEK. A STRONG CLOSED UPPER LOW IS FORECAST
TO MOVE INTO CENTRAL TX BY DAYBREAK WEDNESDAY WITH SURFACE LOW
PRESSURE ALONG THE LA COAST. RAIN WILL SPREAD INTO THE MIDSOUTH
FROM THE SOUTHWEST TUESDAY NIGHT IN ASSOCIATION WITH THIS SYSTEM.
THE LOW PRESSURE SYSTEM IS FORECAST TO TRACK NEAR OR JUST SOUTH OF
NORTH MS WEDNESDAY AND WEDNESDAY NIGHT. RAIN IS FORECAST TO SPREAD
OVER ALL THE MIDSOUTH WEDNESDAY...GRADUALLY ENDING FROM THE WEST
WEDNESDAY NIGHT. MENTIONED LIKELY POPS FOR WEDNESDAY AND WEDNESDAY
NIGHT. SINCE STILL SEVERAL DAYS AWAY...DID NOT GO HIGHER WITH POPS
BUT THEY WILL NEED TO BE RAISED IN LATER FORECASTS IF THE ECMWF IS
CORRECT.
THE LOW PRESSURE SYSTEM WILL MOVE TO OUR EAST BY THURSDAY WITH
RAINFREE WEATHER FROM THURSDAY INTO AT LEAST SATURDAY. THE COLDEST
AIR OF THE SEASON IS FORECAST TO PUSH INTO THE MIDSOUTH BY LATE
THURSDAY AND FRIDAY AS MODIFIED ARCTIC AIR PUSHES INTO THE REGION.
850 MB TEMPERATURES OF MINUS 10C ARE FORECAST ACROSS NORTHERN
LOCATIONS BY FRIDAY. LOWERED THE MEX MOS TEMPERATURES SOME IN THE
EXTENDED. MENTIONED LOWS MOSTLY IN THE 20S AND HIGHS IN THE
40S...BUT WOULD NOT BE SURPRISED TO SEE TEENS IN PARTS OF WEST TN
IF THIS SCENARIO PLAYS OUT AS CURRENTLY FORECAST BY THE ECMWF.
JCL
&&
.AVIATION...
06Z TAFS
DETERIORATING CONDITIONS EXPECTED AT ALL TAF SITES.
MVFR CEILINGS WILL DEVELOP AND MOVE WEST TO EAST ACROSS THE AREA
13-18Z. KEPT VCSH AFTER 15Z AT ALL TAF SITES THINKING THAT -SHRA
WILL BE SCATTERED IN NATURE AND SHORT IN DURATION IF DIRECTLY
AFFECTS A TAF SITE. IFR CONDITIONS AND STEADY RA...POSSIBLY RA+...
CAN BE EXPECTED ALONG AND JUST BEHIND A COLD FRONT WHICH BE NEAR
KJBR AT 00Z...KMEM AND KMKL 03-05Z...AND KTUP NEAR 06Z. CANNOT
RULE OUT A FEW RUMBLES OF THUNDER WITH THE RA AND COLD FRONT
PASSAGE...BUT DID NOT INCLUDE VCTS WITH LOW CONFIDENCE OF THUNDER
OCCURRENCE.
SOUTH WINDS WILL INCREASE TO 8-11 KTS BY 15Z...THEN SHIFT TO THE
NORTH BEHIND THE COLD FRONT WHICH WILL MOVE THROUGH THE AREA
00-06Z. GUSTS AROUND 20 KTS ARE POSSIBLE BEHIND COLD FRONT.
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 60 45 53 36 / 60 100 20 0
MKL 59 42 51 30 / 60 100 20 0
JBR 58 41 52 32 / 60 100 10 0
TUP 61 48 54 34 / 50 100 60 10
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
