985 
FXUS63 KLSX 230001
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
601 PM CST SAT NOV 22 2008

.DISCUSSION...
/229 PM CST SAT NOV 22 2008/
HIGH PRESSURE COVERED THE OH/TN VALLEY THIS AFTERNOON. SOUTHERLY 
WINDS HAVE RETURNED TO THE REGION ON THE BACK SIDE OF THIS HIGH. 
OVERCAST MID LEVEL CLOUDS HAVE PUT A DAMPER ON THE HIGHS TODAY 
ACROSS MOST OF THE FORECAST AREA THOUGH. LOW PRESSURE WILL BECOME 
ORGANIZED OVER THE CENTRAL PLAINS EARLY ON SUNDAY IN RESPONSE TO 
ANOTHERN SHARP UPPER TROF. 

LOW PRESSURE AND THE ASSOCIATED COLD FRONT WILL MOVE ACROSS THE 
REGION SUNDAY NIGHT. THE MODELS ARE FAIRLY SIMILAR AT H5 IN 
FORECASTING A SHARP TROF ROLLING ACROSS THE MIDWEST. WITH DECENT 
SYNOPTIC SCALE AND FRONTAL SCALE FORCING, EXPECT RAIN TO DEVELOP 
AHEAD OF THE FRONT ACROSS PORTIONS OF THE AREA SUNDAY NIGHT.  ALL 
THE MODELS FORECAST A 140 METER HEIGHT FALL CENTER OVER IL MONDAY 
MORNING. HIGH PRESSURE WILL BUILD INTO THE REGION BY TUESDAY AND 
DOMINATE OUR WEATHER PATTERN INTO THANKSGIVING DAY.

THE ECMWF AND GFS FORECAST A SURFACE LOW WILL DEVELOP OVER THE 
SOUTHERN PLAINS EARLY FRIDAY. BOTH MODELS FORECAST THAT RAIN COULD 
OVERSPREAD MUCH OF THE REGION ON FRIDAY WITH COLD EAST-NORTHEAST 
WINDS.

TPS

&&

.AVIATION...
/538 PM CST SAT NOV 22 2008/
FOR THE 00Z TAFS...
VFR FLIGHT CONDITIONS AND LIGHT SOUTHEAST FLOW WILL PREVAIL ACROSS
THE BI-STATE REGION AT LEAST THROUGH EARLY AFTERNOON ON SUNDAY.
MARGINAL CIGS AROUND 2500FT WILL BEGIN OVERSPREADING THE AREA
SUNDAY AFTERNOON AFTER 20Z AHEAD OF THE NEXT STORM SYSTEM. LOOKS
LIKE MOST OF THE AREA WILL BE MARGINAL BY 00Z ON SUNDAY EVENING OR
SHORTLY THEREAFTER. MIGHT SEE SOME COULD ALSO SEE SOME LIGHT RAIN
SHOWERS BEFORE 06Z AS WELL.

CARNEY

&&

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

$$

WFO LSX