FXUS63 KLSX 031134
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
534 AM CST THU DEC 3 2009

.DISCUSSION...
/336 AM CST THU DEC 3 2009/

LOW LEVEL CLOUDINESS DROPPING SEWD THRU THE ERN PORTION OF THE CWA 
ON THE BACKSIDE OF THE SFC LOW OVER LAKE ERIE.  ANOTHER BATCH OF LOW 
LEVEL CLOUDS EXTENDS BETWEEN IRK AND UIN S THRU COU AND VIH WHICH 
WAS ALSO MOVING SEWD.  FLURRIES OR SNOW SHOWERS WERE OCCURRING 
FURTHER N ACROSS PORTIONS OF IA.  THESE WERE ASSOCIATED WITH A LARGE 
MID LEVEL TROF CENTERED OVER MN AND ERN PORTIONS OF ND SD ALONG WITH 
SHRTWVS ROTATING AROUND THE MID LEVEL TROF. ANY MEASUREABLE
PRECIPITATION SHOULD REMAIN N OF THE CWA TDA ALTHOUGH THERE MAY BE
FLURRIES OVER THE NRN PORTION OF THE CWA LATER THIS MRNG AND THIS
AFTN AS A SHRTWV TROF MOVES EWD THRU IA. MOST OF THE CLOUD COVER
WILL BE ACROSS THE NRN PORTION OF THE CWA THIS AFTN AFTER MUCH OF
THE CURRENT CLOUDINESS ADVECTS E OF THE CWA LATER THIS MRNG. BELOW
NORMAL TEMPERATURES ARE EXPECTED TDA AND TGT WITH CONTINUED LOW
LEVEL NWLY WNDS AND CAA. TGT WILL LIKELY BE THE COLDEST NGT OF
THIS FALL SEASON SO FAR AS THE MODELS FORECAST THE -12 DEGREE C
850 MB ISOTHERM TO DROP SEWD TO STL BY 12Z FRI. FRI AND FRI NGT
WILL CONTINUE TO BE VERY COLD AS THE MID-UPPER LEVEL TROF MOVES
EWD THRU THE AREA. AFTER A VERY COLD FRI NGT TEMPERATURES SHOULD
BEGIN TO MODERATE FOR THE WEEKEND AS THE MID-UPPER LEVEL TROF
MOVES E OF THE CWA AND MID-UPPER LEVEL HEIGHTS RISE. 850 MB TEMPS
WILL BE RISING WITH LOW-MID LEVEL WAA ACROSS THE CWA...PLUS THE
SFC WND WILL BECOME SLY ON SAT AS THE SFC RDG MOVES E-SE OF THE
CWA. THE NEXT CHANCE OF PRECIPITATION SHOULD OCCUR MAINLY SUN EVNG
AS A SHRTWV TROF AND ASSOCIATED CDFNT MOVE QUICKLY EWD THRU THE
AREA. IT APPEARS THAT THIS WILL BE A QUICK SHOT OF LIGHT
PRECIPITATION. BASED ON PARTIAL THICKNESS FORECASTS AND FORECAST
SOUNDINGS IT APPEARS THAT THE PRECIPITATION WILL FALL MAINLY AS
SNOW.

GKS

&&

.AVIATION...
/526 AM CST THU DEC 3 2009/

FOR THE 12Z TAFS...

NARROW BAND OF OVC CIGS FROM 3-4 KFT HAS BEEN ROTATING SEWD WITHIN
THE LOW LEVEL CYCLONIC AND WILL AFFECT THE KUIN AND KSTL/KSUS
SITES FOR THE NEXT 2-3 HOURS AND THEN ROTATE INTO IL. IN THE WAKE
OF THIS...SHUD ALSO SEE THE DEVELOPMENT OF SOME SCT DIURNAL CU
ACROSS THE ENTIRE AREA DURING THE LATER HALF OF THE MORNING INTO
THE EARLY AFTERNOON. WEST NORTHWEST WINDS WITH MODEST GUSTS
EXPECTED THROUGH MID-LATE AFTERNOON WITH WINDS DIMINISHING BY SUNSET.

GLASS

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&

$$

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