FXUS63 KLSX 042039
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
239 PM CST FRI DEC 4 2009

.DISCUSSION...
/238 PM CST FRI DEC 4 2009/

SHORTWAVE SLIDING THROUGH THE AREA THIS AFTERNOON WITH SOME DIURNAL 
CU AND FLURRIES OVER THE REGION. BEYOND THIS...MAIN FORECAST ISSUE 
IN THE SHORT TERM IS TEMPERATURES THROUGH THE WEEKEND AND PCPN 
CHANCES SUNDAY NIGHT.

FOR TONIGHT...WILL SEE SOME CLOUDS LINGER EARLY ON...WITH A FEW 
FLURRIES BEFORE CLEARING OUT. RIDGE OF HIGH PRESSURE TO BEGIN MOVING 
OFF TO OUR EAST LATER TONIGHT...ALLOWING SOUTHERLY WINDS TO RETURN 
ONCE AGAIN. HOWEVER...LOW TEMPS TONIGHT WILL STILL DIP INTO THE 
UPPER TEENS.

FOR THE WEEKEND...TEMPERATURES TO MODERATE WITH HIGHS IN THE UPPER 
30S TO LOWER 40S SATURDAY AND SUNDAY. MODELS IN BETTER AGREEMENT 
WITH SYSTEM THAT WILL MOVE IN SUNDAY EVENING...WITH A QUICK SHOT OF 
VERY LIGHT PCPN. PCPN TO BEGIN EITHER AS LIGHT RAIN OR A MIX OF RAIN 
AND SNOW THEN CHANGE OVER TO ALL LIGHT SNOW/FLURRIES BEFORE ENDING 
BY DAYBREAK ON MONDAY. ONLY EXPECT A FEW TENTHS ACCUMULATION OVER 
NORTHEAST MO AND WEST CENTRAL IL...WITH BETTER CHANCES OVER IOWA AND 
NORTHERN IL CLOSER TO UPPER LEVEL SUPPORT.

BEYOND THAT...WILL STILL SEE A BIT OF A BREAK ON MONDAY. MODELS ARE 
CONTINUING TO BRING NEXT...MORE SIGNIFICANT SYSTEM...FURTHER TO THE 
NORTH AND WEST WITH ITS TRACK...THUS SHIFTING HEAVIER SNOW CHANCES 
FURTHER TO THE NORTH.  STILL HAVE UNCERTAINTIES WHEN IT COMES TO 
SNOWFALL AMOUNTS...BUT FEEL THAT THE NORTHERN PORTIONS OF THE CWA 
COULD SEE SOME DECENT SNOWFALL. FURTHER SOUTH AND EAST...TEMPS WILL 
KEEP THE PCPN RAIN A BIT LONGER BEFORE CHANGING TO ALL SNOW TUESDAY 
NIGHT. WITH BETTER CONTINUITY AMONG THE MODELS...FEEL TIMING WITH 
THIS SYSTEM IS GOOD AND UPPED POPS TO LIKELY EVERYWHERE TUESDAY 
NIGHT WHEN SYSTEM IS OVERHEAD. ALL MODELS QUICKLY MOVE THIS SYSTEM 
OUT BY WEDNESDAY NIGHT WITH DRY WEATHER FOR THE REMAINDER OF THE 
EXTENDED.

BYRD
&&

.AVIATION...
/1141 AM CST FRI DEC 4 2009/

FOR THE 18Z TAFS...
EXPECT CLOUDS WITH CIGS 030-035 TO SCT AT KUIN/KSUS/KSTL BY 20Z
AS AREA OF CLOUDS MOVES SLOWLY EWD. ADDITIONAL CLOUD DEVELOPMENT
BEHIND IT SHOULD BE ENOUGH TO KEEP SCT PERHAPS BKN VFR CLOUDS
GOING THE REST OF THE AFTERNOON. SCT --SHSN WILL ALSO BE FOUND
PRIMARILY TO THE N OF I-70 OVER IL THROUGH 21Z. THEN EXPECT SKC
AS CLOUDS QUICKLY DISSIPATE NEAR SUNSET. WLY WINDS 7-10KTS WILL
BECOME LGT/VRB THIS EVENING AS RIDGE AXIS MOVES ACROSS THE
AREA...THEN PICK UP OUT OF THE SOUTH IN THE WAKE OF THE AXIS BY
14-15Z SATURDAY AT 08-10KTS. THERE MAY SOME STEAM FOG DEVELOP IN
THE RIVER VALLEYS LATE TONIGHT...BUT HAVE NOT INCLUDED AT KSUS AT
THIS POINT BECAUSE OF THE VERY DRY ATMOSPHERE AND SOUTHERLY
BOUNDARY LAYER WINDS.

BRITT
&&

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

$$
WFO LSX