FXUS63 KLSX 261203
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
603 AM CST THU NOV 26 2009

.DISCUSSION...
/500 AM CST THU NOV 26 2009/

STRATUS/STRATO-CU REMAIN OVER THE AREA THIS MORNING ON THE BACK SIDE 
OF A STRONG UPPER SHORTWAVE WHICH IS CENTERED OVER THE SOUTHERN TIP 
OF LAKE MICHIGAN.  SOME SPRINKLES/FLURRIES ARE BEING 
REPORTED...PRIMARILY ALONG AND NORTH OF I-70 THIS MORNING.  THIS 
VERY LIGHT PRECIP WILL LIKELY CONTINUE THROUGH MUCH OF THE 
MORNING...BUT WILL BE ENDING FROM WEST TO EAST AS THE TROF MOVES 
FURTHER AWAY FROM THE AREA.  CLOUDS ASSOCIATED WITH THE TROF WILL 
LIKEWISE BE CLEARING FROM WEST TO EAST...BUT THIS WILL LAG THE END 
TO THE PRECIP SOMEWHAT.  GUIDANCE IS FAIRLY CONSISTENT IN CLEARING 
THINGS OUT ACROSS THE AREA BY 00Z TONIGHT.

WITH A CLEAR/MOSTLY CLEAR SKY AND LIGHT WINDS AS THE SURFACE RIDGE 
BUILDS IN TONIGHT WE SHOULD HAVE GOOD RADIATIONAL COOLING 
CONDITIONS.  HAVE THEREFORE KEPT UPPER 20S/LOWER 30S IN THE FORECAST 
FOR FRIDAY MORNING.  EVEN THOUGH WE'LL HAVE A CHILLY START TO THE 
MORNING...RETURN FLOW WILL RAMP UP AS THE SURFACE RIDGE MOVES INTO 
THE OHIO VALLEY.  PLENTY OF SUNSHINE WILL ALSO HELP THE TEMPERATURE 
REBOUND AND HIGHS FRIDAY AFTERNOON COULD BE AS MUCH AS 30 DEGREES 
WARMER THAN THE MORNING LOWS...ESPECIALLY OVER CENTRAL MISSOURI 
WHERE THE SOUTHWEST FLOW WILL PREVAIL FOR A LONGER PERIOD.

ABOVE NORMAL TEMPS AND A MOSTLY SUNNY SKY WILL PREVAIL ON SATURDAY.  
COULD SEE TEMPERATURES AS MUCH AS 15 DEGREES ABOVE NORMAL...BUT THE 
NEXT STORM TO AFFECT THE AREA WILL BEGIN DEVELOPING ON SUNDAY 
BRINGING A CHANCE OF RAIN AND COOLER TEMPERATURES.

CARNEY

&&

.AVIATION...
/538 AM CST THU NOV 26 2009/

FOR THE 12Z TAFS...CIGS DROPPED TO MVFR LEVELS OVERNIGHT AT UIN
AND COU...WITH SFC OBS INDICATING THESE CONDITIONS SLOWLY WORKING
THEIR WAY INTO THE STL AREA OVER THE NEXT HOUR OR SO. RADAR
INDICATES SOME PRECIP IN THE FORM OF RAIN...AND POSSIBLY
SNOW...WILL CONTINUE TO CLIP UIN...STL...AND SUS...BUT DONT
EXPECT ANY REDUCTION IN VSBY DUE TO THE LIGHT NATURE OF THE
PRECIP. MVFR CIGS SHOULD LIFT AROUND MIDDAY...AND WRAP AROUND
CLOUDINESS SHOULD CLEAR FROM W TO E DURING THE AFTERNOON AS THE
LOW OVER THE GREAT LAKES CONTINUES TO DRIFT NE. RAGGED BACK EDGE
OF THE CLOUDINESS HAS NOT BEEN IN ANY BIG HURRY WITH ITS EWD
MOVEMENT...SO BASED ON THIS AND NAM RH PROGS HAVE GONE A BIT
SLOWER WITH THE CLEARING THAN WAS INDICATED IN 06Z TAF SET. GUSTY
NW WINDS WILL PERSIST THEOUGH THE MORNING...BUT SHOULD BEGIN TO
TAPER OFF DURING THE MID-LATE AFTERNOON AS PRESSURE GRADIENT
WEAKENS.

TRUETT

&&

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

$$

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