Severe Thunderstorm Warning 640, NWS Jackson, MS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
300 PM CDT THU SEP 6 2001

UPPER FORCING NOT AS WELL DEVELOPED AS FORECAST FOR TODAY BUT LOW
LEVEL CONVERGENCE AND DIFFERENTIAL MOISTURE BOUNDARY HAVE SERVED AS
FOCUS FOR CONVECTION THIS AFTERNOON. BEST DYNAMICS LOCATED ERN AND
NRN AREAS. CONCERN FOR CENTRAL AREAS IS POSSIBILITY OF OUTFLOW
ACTIVITY PROGRESSING WWD FROM DIMINISHING ERN CONVECTION THIS
EVENING. WITH SLOW MOVING CELL AND LOCALLY STRONG CONVECTION...WILL
SEE FEW AREAS OF HEAVY RAINFALL THIS AFTERNOON AND EVENING. SINCE
UPPER SUPPORT WEAK...EXPECT MOST ACTIVITY TO DIMINISH AROUND DARK.
FORECAST SOUNDINGS DO NOT INDICATE WIDESPREAD DENSE FOG DEVELOPMENT
OVERNIGHT. AREAS OF FOG EXPECTED IN AREAS OF HEAVIER RAINFALL BY
SUNRISE...PARTICULARLY ERN ZONES.

NEXT SHORTWAVE MOVING INTO WRN AR/NE TX TONIGHT. THIS SYSTEM TO
WEAKEN AND SLOWLY DRIFT TO THE E...REMAIN W OF THE MS RIVER AS THE
NEXT STRONGER SHORTWAVE DROPS INTO TX. LOW LEVEL SLY FLOW INCREASING
FRIDAY AS THE LOW PRESSURE SYSTEM DEVELOPS UPSTREAM. MEAN RH VALUES
SOMEWHAT LOWER FOR FRI BUT PRECIPITABLE WATER REMAINS BETWEEN 1.5-2+
INCHES THROUGH THE NEXT FEW DAYS. LOW LEVEL FORCING TO INCREASE
TOMORROW WITH 850 MB WIND 15-20 KTS. BEST CHANCE OF CONVECTION
MOVING TO WRN ZONES FOR FRI WHERE CAPE AND INSTABILITY FIELDS LOOK
MOST UNSTABLE.

GOOD LOW LEVEL SLY FLOW CONTINUING SAT AHEAD OF APPROACHING COLD
FRONT. AIR MASS REMAIN MOIST WITH 10-20 KTS 850 MB WIND AND SURFACE
DEWPOINTS IN THE LOW TO MID 70S RANGE. WEAK LOW LEVEL CONVERGENCE
FORECAST FOR MOST OF FORECAST AREA. RELATIVELY STRONG UPPER
DIVERGENCE INDICATED BY THE AVN. WILL CONTINUE THREAT OF
THUNDERSTORMS FOR SATURDAY...ESPECIALLY FOR THE AFTERNOON AND
EVENING.

EXTENDED MODELS AGREE THAT COLD FRONT TO APPROACH FROM THE W AT THE
END OF THE WEEK. MRF FASTEST...DRAGGING FRONT TO THE E OF THE
FORECAST AREA BY SUN MORNING. OTHER MODELS AGREE ON SLOWER SOLUTION.
MRF AND SLOWER AVN/NOGAPS AGREE ON DRY CONDITION BY MONDAY...
CONTINUING INTO THE EARLY PART OF NEXT WEEK.

.PRELIM NUMBERS...
JAN 73/89/72/88 3425
MEI 71/89/72/88 2424

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

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
071200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
344 PM CDT THU SEP 06 2001

...THUNDERSTORMS...
ISOLATED THUNDERSTORMS ARE EXPECTED TO CONTINUE THROUGH THE
EVENING OVER EXTREME SOUTHEAST ARKANSAS...NORTHEAST LOUISIANA AND
PORTIONS OF CENTRAL AND SOUTHERN MISSISSIPPI. ABUNDANT
MOISTURE...INSTABILITY AND DAYTIME HEATING WILL CONTINUE A CHANCE
OF THUNDERSTORMS THROUGH THE EVENING.  THE STRONGEST ACTIVITY
WILL REMAIN ALONG AND EAST OF INTERSTATE 55. FREQUENT
LIGHTNING...BRIEF DOWNPOURS AND WIND GUSTS TO 35 MPH WILL BE
POSSIBLE. THIS ACTIVITY IS EXPECTED TO DIMINISH SHORTLY AFTER
SUNSET WITH THE LOSS OF AFTERNOON HEATING. SEVERE WEATHER IS NOT
ANTICIPATED.

ACTIVATION OF STORM SPOTTERS...HAM RADIO OPERATORS AND EMERGENCY
MANAGEMENT PERSONNEL IS NOT ANTICIPATED AT THIS TIME.

...FLOODING...
LOCALIZED...VERY HEAVY RAINFALL WILL BE POSSIBLE TODAY OVER
EXTREME SOUTHEAST ARKANSAS...NORTHEAST LOUISIANA AND PORTIONS OF
CENTRAL AND SOUTHERN MISSISSIPPI. WITH ANY SLOW MOVING
STORMS...RAINFALL AMOUNTS OF	OF AROUND ONE HALF INCH WITH
LOCALIZED AMOUNTS OF AROUND 2 INCHES WILL BE POSSIBLE.

THE STAGNANT PATTERN OF DIURNAL...AFTERNOON AND EARLY EVENING
THUNDERSTORMS WILL CONTINUE TODAY AND TONIGHT. THIS WILL BE DUE
TO THE COMBINATION OF A MOIST AIRMASS...AND A SERIES OF WEAK
UPPER LEVEL DISTURBANCES. ALSO...SCATTERED BOUNDARIES FROM THE
PREVIOUS DAYS CONVECTION WILL HELP TO INITIATE THUNDERSTORMS AS
THE TEMPERATURES CONTINUE TO RISE DURING THE AFTERNOON HOURS. THE
STORM MOTIONS SHOULD BE RELATIVELY LIGHT SO LOCALIZED...VERY
HEAVY RAINFALL WILL EXIST WITH HEAVIER SHOWERS AND
STORMS...POSSIBLY CAUSING MINOR FLOODING ALONG WITH PONDING ON
AREA ROADWAYS.

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE AT
WWW.SRH.NOAA.GOV/JAN. THIS INCLUDES THE GRAPHICAL HAZARDOUS
WEATHER OUTLOOK.