000
FXUS63 KLSX 032315
AFDLSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
515 PM CST WED DEC 3 2008
.DISCUSSION...
/234 PM CST WED DEC 3 2008/
A CDFNT CONTS TO MOVE SEWD THRU THE CWA THIS AFTN. THE CDFNT HAS
MADE IT THRU THE STL METRO AREA AND CURRENTLY STRETCHES FROM CNTL
IL...JUST S OF STL AND SWWD JUST S OF SPRINGFIELD MO. AREA OF WWA
PRODUCING DZ/-RA AHEAD OF SFC LOW CONTS TO MOVE SE AND IS ABOUT TO
EXIT THE CWA. FRONTOGENESIS THAT BROUGHT MOD TO HEAVY SN ACRS
PORTIONS OF IA AND NRN MO CONTS TO WEAKEN AS IT MOVES ACRS NRN
PORTIONS OF THE CWA.
FOR TNGT...THE AREA OF PRECIP FURTHER S IS EXPECTED TO MOVE OUT OF
THE AREA BEFORE THE COLD AIR CAN CATCH UP WITH IT. THIS AREA WL
REMAIN LIQUID AS IT EXITS THE CWA. MDLS INDICATE THAT BAND OF SN
FROM NRN IL THRU NRN MO INTO W CNTL MO WL CONT TO MOVE SEWD...BUT
MAY WEAKEN SOME AS IT DOES. AREAS ARE STILL EXPECTED TO RECEIVE
GENERALLY UNDER AN INCH OF SNOWFALL.
BEHIND THE FNT...HIGH PRESSURE BUILDS INTO THE REGION KEEPING
TEMPS BLW SEASONAL AVG. MDLS BRING IN A MID CLD DECK ON
FRI...WHICH WL ALSO HELP TO KEEP TEMPS DWN. MDLS KEEP BNDY LAYER
TOO DRY TO EXPECT ANY PRECIP. OTHERWISE...TEMPS BEGIN TO MODERATE
ON SAT AS SLY FLOW RETURNS. HOWEVER...CLDS WL INCREASE AS WELL.
MDLS HAVE BEEN CONSISTENT BRINGING A CLIPPER SYS ACRS EXTREME NERN
PORTIONS OF THE CWA ON SAT. NAM IS AN OUTLIER WITH THIS SYS AS IT
PLACES THE SFC LOW MUCH FURTHER NW THAN THE GFS OR ECMWF.
ATTM...HAVE ONLY SILENT 20 POPS GOING ACRS NERN MO AND WCNTL IL.
FOR THE EXTD...MDLS ARE IN GD AGREEMENT KEEPING THE REGION DRY UP
TO MON. MDLS BRING ANOTHER CDFNT THRU THE AREA ON MON AND INTO MON
NGT. FOR PRECIP TYPE...THIS EVENT APPEARS SIMILAR TO TDYS. PRECIP
SHUD START OUT AS RA...SWITCH TO A RA/SN MIX BEFORE BCMG ALL SN.
ECMWF AND GFS DIFFER GREATLY REGARDING THERMO PROFILE WITH THIS
SYS. THE ECMWF IS MUCH WRMR WHICH WUD SUGGEST ALL LIQUID PRECIP.
BOTH MDLS ARE PRODUCING OVR ONE HALF INCH OF QPF. MOST OF THIS
PRECIP SHUD BE IN THE FORM OF RA. HOWEVER...THIS SYS WL BE ONE TO
WATCH OVR THE NEXT CPL OF DAYS.
FOR TEMPS IN THE EXTD...HAVE GENERALLY UNDERCUT MOS TEMPS AND
TRENDED TWD THE COOLER GEFS MEAN TEMPS.
TILLY
&&
.AVIATION...
/509 PM CST WED DEC 3 2008/
FOR THE 00Z TAFS...
COLD FRONT HAS PASSED ALL TAF LOCATIONS WITH GUSTY NORTHWEST WIND
AND STRONG COLD ADVECTION IN ITS WAKE. AREA OF LIGHT TO AT TIMES
MODERATE SNOW STRETCHING FROM CENTRAL MISSOURI TO WEST CENTRAL
ILLINOIS WILL MOVE SOUTHEAST...AFFECTING THE ST. LOUIS TAF SITES
BETWEEN 00Z AND 03Z. SHOULD BE A QUICK CLEARING OF LOWER CLOUDS
BEHIND THIS AREA OF SNOW...EVIDENT BY KIRK OBSERVATION OF P6SM SKC
AT 23Z.
OTHERWISE...HIGH CLOUDS SHOULD CLEAR FROM WEST TO EAST OVERNIGHT.
CVKING
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
