Severe Thunderstorm Warning 623, NWS Jackson, MS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
300 PM CDT THU JUL 31 2003

MAIN FORECAST CHALLENGES REMAIN THE CHANCES OF PRECIP THROUGH THE
EXTENDED PERIOD.

SHOWERS AND THUNDERSTORMS HAVE PERSISTED ACROSS MUCH OF THE CWFA
TODAY. EXPECT ACTIVITY TO LINGER INTO THE OVERNIGHT HOURS...AND WILL
NOT WORD ZONES AFTERNOON/EVENING. WATER VAPOR SHOWS DRIER MID AND
UPPER LEVEL AIR POISED TO ENTER THE NORTHWEST CWFA. THIS DRIER MID
AND UPPER LEVEL AIR SHOULD SETTLE OVER AREAS MAINLY NORTH OF THE
INTERSTATE 20 CORRIDOR BY TOMORROW. AT THE SURFACE...THE AIRMASS
WILL REMAIN VERY MOIST WITH DEWPOINTS IN THE LOWER TO MIDDLE 70S
OVER THE ENTIRE CWFA. THE AIRMASS WILL ALSO REMAIN UNSTABLE. WILL
LEAVE IN ISOLATED POPS FOR THE NORTHERN HALF ON FRIDAY...MESOSCALE
FEATURES WILL BE THE MAIN TRIGGERS FOR THUNDER. IN THE SOUTHERN HALF
OF THE CWFA...A WEAK SHEAR AXIS WILL CONTINUE TO SLIP
SOUTHWARD...AND SHOULD HELP TO FIRE SHOWERS AND THUNDERSTORMS ON
FRIDAY.

ON SATURDAY...THE LOWER LEVELS REMAIN VERY MOIST AND UNSTABLE...BUT
THE NOSE OF THE 500MB RIDGE BEGINS TO NUDGE INTO THE WESTERN HALF
OF THE CWFA. WILL HAVE THE HIGHEST POPS IN THE EASTERN HALF OF THE
CWFA. BY LATE SATURDAY NIGHT...THE NEXT FRONTAL BOUNDARY AND STRONG
SHORTWAVE WILL BEGIN APPROACHING THE NORTHERN PORTION OF THE CWFA.
THIS SYSTEM WILL CONTINUE SOUTHWARD ON SUNDAY IN CONJUNCTION WITH AN
UPPER LEVEL JET MAX. STRONG THUNDERSTORMS ARE LIKELY WITH THIS
SYSTEM LATE SATURDAY INTO THE DAY SUNDAY. BY MONDAY...THE FRONT HAS
SLOWED DOWN AS THE BEST UPPER LEVEL DYNAMICS SHIFT OFF TO THE
NORTHEAST. BOUNDARY SHOULD STALL SOMEWHERE NORTH OF I-20 AND BECOME
DIFFUSE.

FOR TUESDAY THROUGH THURSDAY...THINGS REMAIN PRETTY MUCH THE SAME
WITH AN UPPER TROUGH OVER THE EASTERN HALF OF THE US AND MUCH OF THE
CWFA IN NORTHWEST FLOW WITH SEVERAL SHORTWAVES TRAVERSING THE FLOW
TRIGGERING SHOWERS AND THUNDERSTORMS. ANOTHER BOUNDARY IS PROGGED TO
REACH THE LOWER MISSISSIPPI RIVER VALLEY BY THE LATTER HALF OF THE
WEEK. WILL CONTINUE THE CHANCE POPS INTO THE EXTENDED. TEMPS SHOULD
BE NEAR CLIMO...LOWER 90S/LOWER70S.

JAN BB 090/073 093/073 092 07432
    BBBBB 073/092 072/093 072/093 073/092 072 22233333333
MEI BB 090/072 093/071 092 07532
    BBBBB 072/092 072/093 072/093 072/092 071 22333333333

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

32/LISTEMAA

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
011927-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
227 PM CDT THU JUL 31 2003

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

.DAY ONE...TONIGHT AND FRIDAY...

...THUNDERSTORMS...
SCATTERED THUNDERSTORMS ARE EXPECTED THURSDAY EVENING ACROSS
PORTIONS OF SOUTHERN MISSISSIPPI AND NORTHEAST
LOUISIANA...REDEVELOPING FRIDAY AFTERNOON ACROSS THE SAME GENERAL
AREAS. ONLY ISOLATED SHOWERS AND STORMS ARE ANTICIPATED THIS
EVENING AND FRIDAY IN THE REST OF CENTRAL MISSISSIPPI AND
SOUTHEAST ARKANSAS. NON SEVERE THUNDERSTORMS WILL BE CAPABLE OF
PRODUCING DANGEROUS LIGHTNING STRIKES AND HEAVY DOWNPOURS.

A FEW OF THE THUNDERSTORMS AFFECTING SOUTHERN MISSISSIPPI THIS
EVENING COULD BE LOCALLY SEVERE DUE TO HIGH LEVELS OF ATMOSPHERIC
INSTABILITY AND THE INFLUX OF MID LEVEL ENERGY. THE MAIN RISK
WITH ANY SEVERE THUNDERSTORMS WILL BE EXCESSIVE LIGHTNING AND
WIND GUSTS TO 55 MPH. THE STRONGER VARIETY OF STORMS SHOULD
DECREASE IN INTENSITY AFTER SUNSET.

ON FRIDAY A FEW MORE LOCALLY SEVERE THUNDERSTORMS ARE POSSIBLE IN
NORTHEAST LOUISIANA AND SOUTHERN MISSISSIPPI...MAINLY ALONG AND
SOUTH OF THE INTERSTATE TWENTY CORRIDOR. LESS UPPER LEVEL SUPPORT
IS EXPECTED TOMORROW FOR THUNDERSTORM DEVELOPMENT...BUT THE
PRESENCE OF MID LEVEL DRY AIR COULD ALLOW ANY THUNDERSTORMS THAT
FORM TO PRODUCE GUSTY WINDS AND SMALL HAIL.

...FLOODING...
SCATTERED THUNDERSTORMS ARE EXPECTED TO PRODUCE LOCALLY HEAVY
AMOUNTS OF RAIN THURSDAY NIGHT AND FRIDAY ACROSS PORTIONS OF
NORTHEAST LOUISIANA AND SOUTHERN MISSISSIPPI...MAINLY ALONG AND
SOUTH OF A LINE FROM NATCHEZ TO MERIDIAN.

VERY HIGH VALUES OF ATMOSPHERIC MOISTURE PRESENT ACROSS THESE
AREAS OF NORTHEAST LOUISIANA AND SOUTHERN MISSISSIPPI WILL ALLOW
SOME STORMS TO PRODUCE TORRENTIAL DOWNPOURS. ADDITIONALLY...A FEW
LOCATIONS MAY BE AFFECTED BY SEVERAL DIFFERENT THUNDERSTORMS
DURING THIS PERIOD. RAINFALL AMOUNTS IN ISOLATED LOCATIONS BY
LATE FRIDAY COULD REACH UP T0...OR OVER...2 INCHES. PONDING OF
WATER UPON PAVED SURFACES AND IN LOW LYING AREAS IS
POSSIBLE...BUT FLASH FLOODING IS NOT EXPECTED.

.DAYS TWO THROUGH SEVEN...FRIDAY NIGHT THROUGH THURSDAY...

...DAYS TWO AND THREE...FRIDAY NIGHT THROUGH SUNDAY...
STRONG THUNDERSTORMS WILL BE POSSIBLE ACROSS THE OUTLOOK AREA
LATE SATURDAY INTO SUNDAY. THE MAIN RISK WITH STORMS WILL BE HIGH
WINDS AND HAIL.

AN ACTIVE NORTHWEST FLOW PATTERN WILL SEND ANOTHER UPPER LEVEL
TROUGH OF LOW PRESSURE TOWARD THE LOWER MISSISSIPPI VALLEY REGION
BY THE WEEKEND. MID AND UPPER LEVEL WIND FIELDS WILL INCREASE BY
LATE SATURDAY. THESE WIND FIELDS...ALONG WITH EXPECTED LOW LEVEL
INSTABILITY...WILL GIVE THUNDERSTORMS THE POTENTIAL TO BE SEVERE.

...DAYS FOUR THROUGH SEVEN...SUNDAY NIGHT THROUGH THURSDAY...
THE UPPER LEVEL TROUGH OF LOW PRESSURE BRINGING THE RISK FOR
INTENSE THUNDERSTORMS OVER THE WEEKEND LOOKS TO HANG AROUND
THROUGH EARLY NEXT WEEK. THIS WILL PROLONG THE CHANCE FOR STRONG
THUNDERSTORMS THROUGH AT LEAST MONDAY...AND POSSIBLY TUESDAY.
PERSONS MAKING OUTDOOR PLANS EARLY NEXT WEEK SHOULD KEEP UP TO
DATE ON THE LATEST FORECAST FOR THIER AREA.

.SPOTTER CALL TO ACTION STATEMENT...
THE ACTIVATION OF STORM SPOTTERS...HAM RADIO OPERATORS...AND
EMERGENCY MANAGEMENT PERSONNEL IN SUPPORT OF SEVERE WEATHER
OPERATIONS...COULD BE NECESSARY THIS EVENING ACROSS PORTIONS OF
SOUTHERN MISSISSIPPI AND NORTHEAST LOUISIANA.

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