Severe Thunderstorm Warning 339, NWS Jackson, MS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
300 AM CDT SUN JUL 21 2002...CORRECTED PRELIM NUMBERS

MAIN FORECAST PROBLEM WILL BE DISTRIBUTION OF CONVECTION NEXT FEW
DAYS. PRECIPITABLE WATER VALUES REMAIN WELL ABOVE 1.5 INCHES OVER
THE NEXT COUPLE OF DAYS SO PROBLEM WILL BE DETERMINING LOCATIONS OF
FORCING. AFTERNOON HEATING WILL PRODUCE AT LEAST ISOLATED COVERAGE
EVERYWHERE BUT BEST CHANCE FOR TODAY LOOKS AGAIN TO BE NRN AREA OF
FORECAST AREA. HIGHEST CAPE AND 850 MB THETAE VALUES FORECAST NRN
ZONES BY EARLY AFTERNOON. MODELS ALSO SHOW JET MAX DRAPED ACROSS TN
INTO NRN MS THAT SHOULD PROVIDE SMALL AMOUNT OF UPPER DIVERGENCE.
UPPER TROUGH REMAINS EAST OF MS BUT WRN EDGE POKES INTO ERN MS AND
WAVES IN UPPER FLOW MAY PROVIDE SMALL AMOUNT OF FORCING FOR ISOLATED
TO SCATTERED CONVECTION THIS AFTERNOON AND EVENING. WEAK SHEAR ZONE
NOTED ON SATELLITE PIX ACROSS NORTH CENTRAL MS PUSHING SLOWLY SWD.
THIS WILL AID DEVELOPMENT FOR CENTRAL AREA THIS AFTERNOON. STRONGER
CONVECTION NR MS COAST EXPECTED TO LEAVE OUTFLOW BOUNDARY THAT WILL
MAINTAIN CHC OF AFTERNOON CONVECTION INTO SE SXN OF FORECAST AREA.
WITH ALL THESE POSSIBILITIES WILL GO WITH CHC POPS ALL OF AREA
WITH LEAST CHC FOR SW AREAS TODAY.

JET MAX WASHING OUT OVER TN MON AFTERNOON. AIR MASS REMAINS UNSTABLE
WITH BEST CAPES AGAIN NRN ZONES EARLY IN AFTERNOON...INCREASING OVER
CENTRAL AND SRN ZONES BY 00Z TUE...BUT NOT MUCH SEEN IN WAY OF
FORCING.

AVN SLOWER ON SWD PROGRESSION OF NEXT SIGNIFICANT COLD FRONT...
DROPPING IT INTO TN/AR TUE MORNING AS DOES THE ETA. AVN MOVES THE
BOUNDARY INTO SRN AREAS WED...WHERE IT STALLS NEAR THE COAST THROUGH
FRI MORNING BEFORE WASHING OUT. WILL GO WITH CURRENT EXTENDED AT
THIS TIME KEEPING CHANCE OF THUNDERSTORMS THROUGH LATE THIS WEEK.

PRELIM NUMBERS:
JAN 94/74/94/74 4232
MEI 95/72/95/72 4232

.JAN...
AR...NONE.
LA...NONE.
MS...NONE.