Severe Thunderstorm Warning 199, NWS Paducah, KY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PADUCAH KY
133 PM CDT THU SEP 19 2002

PRIMARY SHORTWAVE TROUGH OVER THE CENTRAL PLAINS WILL HAVE PLENTY OF
MOISTURE TO WORK WITH AS IT LIFTS NORTHEAST ACROSS THE GREAT LAKES
REGION OVER THE NEXT 36 HOURS. BANDS OF CONVECTION WILL FORM ALONG
AND AHEAD OF THE COLD FRONT...GIVING MOST AREAS SOME LOCALLY HEAVY
RAIN. LATEST RADAR AND LIGHTNING IMAGES SHOW A LARGE BAND OF
CONVECTION FROM THE MISSOURI BOOTHEEL...SOUTHWEST TO THE ARKLATEX
REGION. MORE SCATTERED CONVECTION HAS DEVELOPED OVER THE EVV
TRI-STATE AREA WHERE THERE HAS BEEN PLENTY OF SUN.

SHORT TERM CONCERNS ARE FINE TUNING POPS AND EVALUATING HEAVY RAIN
POTENTIAL. ALL MODELS ARE CRANKING OUT SOME HEFTY QPF TONIGHT AND
FRIDAY...ON THE ORDER OF 2 TO 3 INCHES. SUBTLE DIFFERENCES EXIST
WITH REGARD TO THE AXIS OF HEAVIEST RAINFALL...WITH THE AVN MODEL
TENDING TO KEEP THE MAXIMUM QPF RIGHT ALONG THE COLD FRONT. ETA
CRANKS OUT THE HEAVIEST QPF OVER WRN KENTUCKY/SW INDIANA
TONIGHT...THEN DEVELOPS ANOTHER BAND OF HEAVY RAIN ALONG THE FRONT
EARLY FRIDAY. THE ETA QPF APPEARS TO BE VERIFYING BETTER...BASED ON
THE CURRENTLY OBSERVED BAND OF STORMS OVER ERN ARKANSAS. CATEGORICAL
POPS AND MENTION OF LOCALLY HEAVY RAIN APPEARS WARRANTED IN ALL
AREAS TONIGHT. THE GROUND SHOULD BE ABLE TO HANDLE SOME HEAVY RAIN
DUE TO THE ONGOING DROUGHT. EXTENSIVE CLOUDINESS AND WARM MID LEVEL
TEMPS WILL RESULT IN MARGINAL INSTABILITY FOR A SEVERE WEATHER THREAT
/PER SPC DAY ONE OUTLOOK/...WITH BOWING LINE SEGMENTS THE MAIN
CONCERN.

AVN/ETA ARE IN BETTER AGREEMENT WITH THE TIMING OF THE COLD FRONT
FRIDAY. EVEN WITH THE FRONT THROUGH THE FORECAST AREA BY THE END OF
THE DAY...AVN STILL LINGERS SOME PRECIP ACROSS WRN KENTUCKY AND SW
INDIANA INTO FRIDAY EVENING. THE 850 MB TROUGH LAGS THE COLD FRONT
BY ABOUT 6 HOURS...WHICH APPEARS TO BE WHY THE MODELS LINGER PRECIP
INTO THE EVENING. WILL NOT FIGHT AVN/NGM/ETA MOS...ALL OF WHICH
LINGER POPS INTO THE EVENING FOR EASTERN ZONES.

A VERY QUIET WEEKEND IS EXPECTED. FIRST WAVE OF COOLER AND DRIER AIR
WILL ARRIVE FRIDAY NIGHT...FOLLOWED BY A SECOND SURGE LATE SATURDAY.
THIS SECONDARY FRONT WILL BE ASSOCIATED WITH A CLIPPER TYPE
SHORTWAVE CROSSING THE MISSISSIPPI VALLEY IN NORTHWEST FLOW. VERY
LITTLE MOISTURE WILL BE AVAILABLE FOR CLOUDINESS ALONG THE FRONT.

BIGGEST CHANGE FOR NEXT WEEK IS THAT THE MRF/AVN ENSEMBLES ARE
DEEPER WITH THE 500 MB TROUGH OVER THE NORTH CENTRAL U.S. THIS
RESULTS IN A STRONGER PUSH OF COOL AND DRY AIR INTO OUR FORECAST
AREA. HPC AND MRF MOS GUIDANCE SHOWS LOWS IN THE 40S EARLY IN THE
WEEK.

.PAH...NONE.

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