Severe Thunderstorm Warning 635, NWS Jackson, MS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
320 AM CDT SUN AUG 3 2003

FORECAST THINKING IS RELATIVELY UNCHANGED FROM PREVIOUS DAYS AS THE
ACTIVE NORTHWEST FLOW CONTINUES...AND IS EXPECTED TO CONTINUE WELL
INTO THE COMING WEEK. LATEST WX ANALYSIS INCLUDING RUC/PROFILER DATA
INDICATES THAT A CONVECTIVE SYSTEM WILL CONTINUE TO DEVELOP OVER THE
OZARK REGION ALONG AXIS OF STRONGER SFC-850MB MOISTURE CONVERGENCE
AND INCREASINGLY FAVORABLE POSITION RELATIVE TO STRONG UPPER JET
CORE. EXPECT ANY COMPLEX TO EVOLVE E-SE INTO THE FORECAST AREA LATER
TODAY...PERHAPS SIMILAR TO YDAYS CONVECTIVE EVOLUTION. THERE SHOULD
BE AN INCREASING RISK FOR DAMAGING WIND GUSTS GIVEN EXPECTED SURFACE
BASED CAPES 5000 J/KG...STEEP LOW LEVEL LAPSE RATES...AND
LIKELIHOOD OF STORM ORGANIZATION. SEVERE WX POSSIBILITY WILL
CONTINUED TO BE MENTIONED IN THE HWO FOR TODAY.

HAVE INCREASED POPS FOR MONDAY ABOUT 10-20% WITH MODELS KEEPING
FORECAST AREA IN MOIST CONVERGENCE REGIME WITH PRECIP WATER VALUES
2 INCHES. ALSO...THE GFS IS SHOWING GOOD RUN-TO-RUN CONSISTENCY IN
HITTING TUESDAY HARD AS AN ACTIVE TSTM DAY. STRONG/SVR WX
POSSIBILITY WILL BE MENTIONED THROUGH 2-7 DAY PERIOD IN THE HWO.

LATEST GFS/UKMET/ECMWF MODELS INDICATE THAT THE UPPER FLOW PATTERN
WILL AMPLIFY ENOUGH BY THE END OF THE WEEK TO BRING QUIET WX FOR A
WHILE. WILL HOLD OFF ON ANY CHANGES TO GRID FORECASTS FOR NOW.

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

43

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
040919-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
419 AM CDT SUN AUG 03 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL MISSISSIPPI...
NORTHEAST LOUISIANA...AND EXTREME SOUTHEAST ARKANSAS

.DAY ONE...TODAY AND TONIGHT...

...THUNDERSTORMS...
SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE OVER EXTREME
SOUTHEAST ARKANSAS...NORTHEAST LOUISIANA AND MUCH OF MISSISSIPPI
TODAY AND TONIGHT. SCATTERED SEVERE THUNDERSTORMS CAN BE EXPECTED
OVER AREAS ALONG AND NORTH OF INTERSTATE 20 AND ISOLATED SEVERE
THUNDERSTORMS CAN BE EXPECTED SOUTH OF INTERSTATE 20.

A MOIST AND VERY UNSTABLE AIRMASS REMAINS OVER THE LOWER
MISSISSIPPI RIVER VALLEY. SHOWERS AND THUNDERSTORMS WILL CONTINUE
TO DEVELOP THIS MORNING AND LINGER INTO THE EVENING. DURING THE
AFTERNOON...AN OUTFLOW BOUNDARY FROM A DYING THUNDERSTORM COMPLEX
WILL BEGIN APPROACHING FROM THE NORTHWEST...MUCH LIKE YESTERDAY.
THIS OUTFLOW BOUNDARY WILL COMBINE WITH STRONG JET STREAM
ENERGY...AN UPPER LEVEL DISTURBANCE AND DAYTIME HEATING TO
PRODUCE SCATTERED SEVERE STORMS NORTH OF INTERSTATE 20. WITH THE
BEST JET STREAM ENERGY REMAINING OVER NORTHERN PORTIONS OF THE
OUTLOOK AREA...ONLY ISOLATED SEVERE STORMS ARE EXPECTED OVER
AREAS SOUTH OF THE INTERSTATE 20 CORRIDOR THIS AFTERNOON AND
EVENING.

SEVERE STORMS WILL BE CAPABLE OF PRODUCING WIND GUSTS TO 60 TO 70
MPH. ALL STORMS WILL PRODUCE FREQUENT LIGHTNING STRIKES AND HEAVY
DOWNPOURS.

...FLOODING...
SCATTERED SHOWERS AND THUNDERSTORMS WILL PRODUCE LOCALLY HEAVY
RAINFALL OVER MUCH OF THE OUTLOOK AREA TODAY AND TONIGHT.
RAINFALL RATES UP TO AN INCH AN HOUR WILL BE POSSIBLE IN THE
STRONGER STORMS...AND WILL LIKELY PRODUCE PONDING OF WATER ON
ROADWAYS AND IN LOW LYING AREAS.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY...

...DAYS TWO AND THREE...MONDAY AND TUESDAY...
STRONG TO SEVERE THUNDERSTORMS ARE ONCE AGAIN EXPECTED OVER THE
ENTIRE OUTLOOK AREA ON MONDAY AND TUESDAY.

THE WEATHER PATTERN WILL REMAIN MUCH THE SAME THROUGH TUESDAY AS
A SERIES OF UPPER LEVEL DISTURBANCES CONTINUE TO INTERACT WITH
THE MOIST AND UNSTABLE AIRMASS OVER THE LOWER MISSISSIPPI RIVER
VALLEY. A FRONTAL BOUNDARY SAGGING SOUTHWARD OVER NORTHERN
PORTIONS OF THE OUTLOOK AREA WILL ALSO PROVIDE ADDITIONAL SUPPORT
FOR THUNDERSTORM DEVELOPMENT.

...DAYS FOUR THROUGH SEVEN...WEDNESDAY THROUGH SATURDAY...
THE WEATHER PATTERN WILL REMAIN ACTIVE THROUGH THE REMAINDER OF
THE WEEK INTO THE WEEKEND. STRONG THUNDERSTORMS WILL BE POSSIBLE
EACH DAY AS UPPER LEVEL DISTURBANCES CONTINUES TO INTERACT WITH
THE MOIST AND UNSTABLE AIRMASS IN PLACE.

.SPOTTER CALL TO ACTION STATEMENT...
THE ACTIVATION OF STORM SPOTTERS...HAM RADIO OPERATORS...AND
EMERGENCY MANAGEMENT PERSONNEL IN SUPPORT OF SEVERE WEATHER
OPERATIONS...WILL BE NECESSARY THIS AFTERNOON AND TONIGHT.

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