FXUS63 KLSX 091155
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
555 AM CST WED DEC 9 2009

.DISCUSSION...
/411 AM CST WED DEC 9 2009/

FOCUS HAS TURNED FROM SN ACCUMS TO WIND ADV TODAY...WIND CHILL 
VALUES FOR TNGT AND TEMPS INTO THE WEEKEND. 

SFC LOW CURRENTLY CENTERED OVR NRN IL WILL CONT TO MOVE OFF TO THE
NE TDA. AS IT DOES...-SN AND FLURRIES WILL BE POSS ON THE BACKSIDE
OF THE LOW...MAINLY THIS MRNG. THIS LOW WILL ALSO BE RESPONSIBLE
FOR STRONG NWLY TO WLY WINDS...WITH GUSTS UP TO 50 MPH. SOME
DAMAGE HAS ALREADY BEEN REPORTED EARLY THIS MRNG. WINDS SHUD BEGIN
TO DIMINISH SOMEWHAT THIS AFTN. 

FOR TNGT...SKIES SHUD CLEAR OUT LATE THIS EVE. THIS WILL ALLOW
AMPLE RADIATIONAL COOLING TNGT. HAVE TRENDED TEMPS DOWN A COUPLE
OF DEGREES...JUST BELOW THE COOLEST MOS. DID NOT GO TOO COLD AS
WINDS TNGT SHUD HELP KEEP TEMPS FROM DROPPING TOO LOW.
HOWEVER...THIS COMBINATION PRESENTS ANOTHER HAZARD WITH WIND
CHILLS NEARING 15 DEGREES BELOW ZERO. WILL HOLD OFF WITH ADV FOR
NOW AND ALLOW THE DAY SHIFT TO TAKE A CLOSER LOOK. 

TEMPS SHUD MODERATE BEGINNING TMW WITH SFC RIDGE SETTLING IN PLACE
OVR THE REGION. THE WARMUP WILL BE DELAYED SOMEWHAT AS REGION WILL
NOT SEE GOOD RETURN FLOW OPEN TO THE GULF UNTIL LATE FRI AND INTO
THE WEEKEND. 

UPA PATTERN BCMGS ZONAL BEHIND THIS SYS...LEAVING A DRY FCST
BEYOND THIS MRNG. MDLS AGREE WELL WITH S/W...POSSIBLY BRINGING
SOME LIGHT PRECIP TO THE SRN PORTIONS OF THE CWA LATE SAT AND INTO
SUN. HAVE ONLY SILENT 20 POPS FOR NOW AS AMNT OF MSTR RETURN TO
THE REGION IS UNCERTAIN...AND FORCING AT ALL LVLS IS MEAGER AT
BEST. 

A STRONGER SYS WITH AN ACCOMPANIED SFC LOW IS PROGD TO REACH THE
CWA EARLY MON. MDL SONLS VARY WITH REGARD TO BOTH TIMING/POSITION
AS WELL AS AMNT OF FORCING AND PRECIP WITH THE SYS. PREV FCST HAD
SILENT 20 POPS AND WILL LEAVE AS IS FOR NOW UNTIL MDLS BEGIN TO
CONVERGE ON A SOLN. 

TILLY

&&

.AVIATION...
/555 AM CST WED DEC 9 2009/

FOR THE 12Z TAFS...STRONG AND GUSTY WLY SFC WNDS WILL PREVAIL AS
LONG AS WE HAVE A SC CLOUD DECK...AND WE ARE EXPECTING CLEARING TO
OCCUR OVER MUCH OF THE FA DURING THIS EVENING. THE STRONGEST GUSTS
SHOULD OCCUR THRU 18-20Z WITH GRADUAL DIMINISHING THEREAFTER...AND
EVEN AFTER CLOUDS CLEAR OUT WE SHOULD STILL SEE SOME GUSTS TO
20KTS BUT MUCH LOWER THAN EARLIER IN THE TAF PERIOD. THE ITEM OF
GREATEST UNCERTAINTY WILL BE VSBYS THIS MORNING AS RESIDUAL AREA
OF SNOW MOVES THRU. WHEN THE HEAVIER SNOW DOES MOVE THRU...SHOULD
SEE VSBYS DROP TO MVFR MOST TAF SITES WITH KUIN BEING MOST
FAVORABLE FOR SOME IFR CONDS. KCOU WILL BE ON THE EDGE OF POSSIBLE
BRIEF IFR SNOW.

TES

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR AUDRAIN-BOONE-
     CALLAWAY-COLE-CRAWFORD-FRANKLIN-GASCONADE-IRON-JEFFERSON-
     KNOX-LEWIS-LINCOLN-MADISON-MARION-MONITEAU-MONROE-
     MONTGOMERY-OSAGE-PIKE-RALLS-REYNOLDS-SHELBY-ST. CHARLES-ST. 
     FRANCOIS-ST. LOUIS-ST. LOUIS CITY-STE. GENEVIEVE-WARREN-
     WASHINGTON.

IL...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR ADAMS IL-BOND IL-
     BROWN IL-CALHOUN IL-CLINTON IL-FAYETTE IL-GREENE IL-JERSEY 
     IL-MACOUPIN IL-MADISON IL-MARION IL-MONROE IL-MONTGOMERY IL-
     PIKE IL-RANDOLPH IL-ST. CLAIR IL-WASHINGTON IL.

&&

$$

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