000
FXUS63 KLSX 220748
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
248 AM CDT WED MAY 22 2013

.SHORT TERM...(THROUGH TONIGHT)
ISSUED AT 138 AM CDT WED MAY 22 2013

FOCUS CONTINUES TO BE PRECIP CHANCES TODAY.

GIVEN MDL PERFORMANCE OVER THE PAST 24 HRS...HAVE LOWER THAN
NORMAL CONFIDENCE IN FORECAST FOR TODAY. TO ADD TO THIS LOW
CONFIDENCE...THE LATEST MDL DATA SUGGESTS TSRA SHUD BE MUCH MORE
WIDESPREAD ACROSS SRN MO INTO AR ASSOCIATED WITH THE RATHER STRONG
S/W CURRENTLY ROUNDING THE BASE OF THE UPPER LOW. THIS S/W STILL
HAS THE POTENTIAL TO PRODUCE SOME PRECIP LATER THIS MORNING IF THE
LLJ CAN RESPOND BEHIND THE LINE OF CONVECTION ACROSS THE SRN US.

ANOTHER S/W CURRENTLY OVER SRN NEB IS PROGD TO ROUND THE BASE OF
THE UPPER LOW LATER TODAY. THIS S/W SHUD HELP INITIATE ISOD TO SCT
CONVECTION THIS AFTERNOON ALONG THE CDFNT. BELIEVE BEST CHANCES
WILL BE ACROSS SE MO AND SW/S CNTL IL WHERE LOW LEVEL LAPSE RATES
WILL BE STEEPER. ANY PRECIP THAT DEVELOP THIS AFTERNOON SHUD
DISSIPATE QUICKLY WITH SUNSET.

AS FOR TEMPS...TRENDED AOB COOLEST MOS ACROSS THE NWRN THIRD OF
THE CWA AND NEAR THE WARMEST MOS ELSEWHERE FOR TODAY. TRENDED A
LITTLE COOLER TONIGHT AS THE CWA WILL BE BEHIND THE CDFNT.
HOWEVER...DID NOT GO TOO MUCH COOLER AS CLOUD COVER SHUD HELP KEPT
TEMPS A LITTLE WARMER.

.LONG TERM...(WEDNESDAY THROUGH NEXT TUESDAY)
ISSUED AT 314 PM CDT TUE MAY 21 2013

THE MAJORITY OF THE PRECIPITATION SHOULD BE EAST OF THE MS RIVER
IN ILLINOIS OR FURTHER EAST AT DAYBREAK AND CONTINUE TO MOVE
EASTWARD AS THE SHORTWAVE TROF AND ATTENDANT COLD FRONT MOVE EAST.
COOLER AND DRIER AIR WILL OVERSPREAD THE REGION IN THE WAKE OF THE
FRONT AND ANY ADDITIONAL PRECIPITATION THREAT AFTER MID-MORNING
SHOULD BE FROM ISOLATED DIURNAL SHOWERS. ANOTHER SECONDARY COLD
FRONT WILL PUSH THROUGH THE AREA WED NIGHT USHERING HIGH PRESSURE
AND EVEN COOLER AIR INTO THE AREA. THIS LARGE HIGH WILL DOMINATE
THE AREA THURSDAY INTO FRIDAY.

NOT MUCH HAS CHANGED IN THE EXTENDED RANGES OF THE FORECAST. AN
UPPER RIDGE WILL DOMINATE THE CENTRAL U.S. WITH THE RIDGE AXIS
REMAINING JUST WEST OF MISSOURI SAT-MON. THIS WILL PLACE US JUST
DOWNSTREAM OF THE RIDGE CREST AND SUBJECT TO WEAK SHORT WAVES
TOPPING THE RIDGE. THESE DISTURBANCES COMBINED WITH RETURN FLOW
AND LOW LEVEL WAA ON THE BACKSIDE OF THE RETREATING LOW LEVEL HIGH
PRESSURE SYSTEM WILL BRING A PROLONGED THREAT OF SHOWERS AND
THUNDERSTORMS TO PRIMARILY THE NORTHERN HALF OF THE CWA FROM SAT
THROUGH MON NIGHT. THEREAFTER THE UPPER RIDGE AXIS MOVES TO OUR
EAST...PRECIPITATION CHANCES DIMINISH AND TEMPERATURES WARM.

GLASS

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1148 PM CDT TUE MAY 21 2013

RECENT RADAR IMAGERY IS SHOWING RAIN DEVELOPING IN FAR SOUTHWEST
MISSOURI THAT WILL MOVE NORTHEAST AND IMPACT THE ST. LOUIS METRO
TAF SITES BEFORE 12Z. A WEAK STORM SYSTEM WILL MOVE ACROSS NORTHERN
MISSOURI ON WEDNESDAY WHICH MAY BRING LIGHT SHOWERS TO KUIN DURING
THE AFTERNOON. EXPECT MANY VFR CONDITIONS THROUGH THE PERIOD
EXCEPT FOR MVFR CONDITIONS WITH SHOWERS.

SPECIFICS FOR KSTL...RAIN DEVELOPING OVER SOUTHWEST MISSOURI WILL
MOVE NORTHEAST THE NEXT FEW HOURS AND MOVE INTO THE TERMINAL
BEFORE 12Z. OTHERWISE...DRY AND VFR CONDITIONS ARE EXPECTED.

BRITT

&&

.PRELIMINARY POINT TEMPS/POPS...
SAINT LOUIS     56  71  49  72 /  10  10   0   0
QUINCY          53  66  46  69 /  10  20   0   0
COLUMBIA        53  70  49  71 /  10  10   0   0
JEFFERSON CITY  54  71  50  72 /  10   5   0   0
SALEM           57  70  46  70 /  10  20   0   0
FARMINGTON      55  73  47  71 /  10  10   0   0

&&

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

$$

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