Severe Thunderstorm Warning 648, NWS Jackson, MS

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE JACKSON MS
320 AM CDT THU OCT 11 2001

CORRECTED FOR LAST PERIOD TEMPS/POPS

SUBTROPICAL JET AXIS FROM S TX TO CENTRAL MS ARCHING NWD IN THE
LOWER MS VALLEY THIS MORN. AREA OF SHOWERS/THUNDERSTORMS MOVING NE
WITH UPPER FLOW ACROSS AR/MS DELTA...WHILE PRECIP LIMITED OVER MOST
OF CWFA ATTM.

COLD FRONT WILL PUSH E TO ARLATX BY 12Z TODAY. APPEARS BOUNDARY
SLOWS/STALLS AROUND ARLAMS...WITH PRECIP TRAINING OVER REGION.
SHORTWAVE/DEEPENING SURFACE LOW PRESSURE SYSTEM WILL TAP INTO JET
ENERGY TO PRODUCE WIDESPREAD CONVECTION...ESPECIALLY OVER NW ZONES.
THOUGH PRECIP EXPECTED OVER SERN ZONES...WILL TAPER POPS SINCE
SUBTROPICAL RIDGE CURRENTLY SUPPRESSING DEVELOPMENT.

PRECIP WATER VALUES AROUND 2 OVER ARLAMS TODAY. COPIOUS RAINFALL
COULD OCCUR TODAY WITH AMOUNTS TO 3 POSSIBLE NW DUE TO TRAINING
ECHOES. COULD SEE INCREASING FLASH FLOOD POTENTIAL. WILL MENTION
LOCALLY HEAVY RAINFALL IN ZONES. NEXT SHIFT WILL BE IN BETTER
POSITION TO EVALUATE TRENDS.

ETA/NGM TRACK SURFACE LOW NE INTO IN/IL 00Z-06Z FRI...WITH NGM
SLIGHTLY FASTER THAN ETA. AVN SLOWEST...WITH SURFACE LOW CENTERED
OVER N MS AT 06Z FRI. THIS DEVELOPMENT COULD MEAN SIGNIFICANT
DIFFERENCE IN PRECIP CHANCES/AMOUNTS FOR CWFA...DEPENDING UPON WHICH
MODEL YOU BELIEVE. WILL ACCEPT ETA/NGM SOLUTIONS...SINCE THEY APPEAR
TO BE IN LINE WITH CURRENT TRENDS OF SHORTWAVES PUSHING NE ALONG
SUBTROPICAL JET AXIS. WITH THAT SAID...HEAVIEST PRECIP WILL OCCUR N
OF CWFA. REGARDLESS...6-HR RAINFALL AMOUNTS WILL BE HEFTY WITH LOCAL
AMOUNTS TO 3 POSSIBLE...MAINLY OVER NRN/CENTRAL ZONES AS SURFACE
BOUNDARY PROGRESSES E.

RAINFALL WILL TAPER OFF AFTER 18Z FRI...AS BOUNDARY PULLING OUT OF
CWFA. EVER SO SLIGHT REPRIEVE IN CONVECTION CONTINUES THROUGH 00Z
SAT...AS DRIER AIR FILTERS INTO REGION. BREAK WILL BE SHORT THOUGH
SINCE NEXT SYSTEM WILL BE DEVELOPING OVER PLAINS.

SEVERE POTENTIAL INCREASES AFTER 00Z SAT (FRI NIGHT)...SINCE 500 MB
SYSTEM DEEPENING OVER PLAINS. LOW PRESSURE AREA CLOSES OFF AT
300MB/500MB AS UPPER LEVEL DIVERGENCE BULLS-EYED OVER MS IN AVN BY
12Z SAT. ETA KINDA WASHES THIS FEATURE OUT BETWEEN 06Z-12Z. MASSIVE
HEIGHT FALLS OCCUR AROUND 06Z SAT OVER OK/N TX IN ALL MODELS...AS
TROUGH BECOMING NEGATIVELY TILTED/SWINGS E TOWARDS MS RIVER VALLEY.
LOWER-LEVEL JET INCREASES TO OVER 50 KTS...WHILE COUPLED UPPER-LEVEL
JET STRUCTURE SCARY ALREADY...PARTICULARLY IN AVN BY 12Z. SURFACE
FRONT APPEARS TO REACH MS RIVER AT THIS TIME. IN ALL...SAT LOOKS
REALLY ROUGH WITH SEVERE WEATHER A GOOD BET. JET STRUCTURE SUPPORTS
POSSIBLE TORNADOES. LOCALLY HEAVY RAINFALL AMOUNTS OVER 2 POSSIBLE
AGAIN SAT.

CONVECTION/RAIN ENDS BY 12Z SUN...AS SURFACE FRONT PUSHES INTO SERN
STATES. HIGH PRESSURE BUILDS OVER CWFA.

.EXTENDED FORECAST...
HIGH PRESSURE WILL DOMINATE WX OVER CENTRAL PORTION OF COUNTRY. DRY
DAYS WITH COOL NIGHTS EXPECTED THROUGH MID WEEK.

.PRELIM NUMBERS...
JAN 076/067/081/064  +857
MEI 075/064/081/062  9966

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

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
121200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
619 AM CDT THU OCT 11 2001

...THUNDERSTORMS...
ISOLATED THUNDERSTORMS WILL OCCUR OVER PARTS OF SOUTHEAST
ARKANSAS...NORTHEAST LOUISIANA...AND WESTERN MISSISSIPPI THIS
MORNING. THUNDERSTORMS WILL INCREASE ACROSS THE REGION DURING THE
AFTERNOON AND ISOLATED STORMS MAY BECOME SEVERE. THE BEST THREAT
FOR SEVERE STORMS WILL BE OVER SOUTHEAST ARKANSAS...NORTHEAST
LOUISIANA AND PARTS OF WEST MISSISSIPPI DURING THE LATE MORNING
AND EARLY AFTERNOON AND OVER EAST MISSISSIPPI LATER IN THE DAY.
THE PRIMARY SEVERE WEATHER THREAT WILL BE DAMAGING WIND UP TO 70
MILES AN HOUR AND HAIL THE SIZE OF DIMES.

A SLOW MOVING COLD FRONT WILL TRACK ACROSS THE REGION THIS
AFTERNOON AND TONIGHT. THUNDERSTORMS WILL DEVELOP AHEAD OF THE
BOUNDARY IN THE MOIST AND UNSTABLE AIR MASS CURRENTLY IN PLACE.

ACTIVATION OF HAM RADIO OPERATORS...AND EMERGENCY MANAGEMENT
PERSONNEL MAY BE NECESSARY THIS AFTERNOON OR TONIGHT.

...FLOODING...
RAINFALL WILL INCREASE FROM THE WEST TODAY AS A SLOW MOVING COLD
FRONT APPROACHES. PERIODS OF HEAVY RAIN ARE POSSIBLE AND MAY
CAUSE PONDING OF WATER ON ROADWAYS AND IN LOW LYING AREAS.

A SLOW MOVING COLD FRONT WILL APPROACH THE REGION TODAY. THE
FRONT WILL MOVE INTO SOUTHEAST ARKANSAS AND NORTHEAST LOUISIANA
DURING THE LATE AFTERNOON AND INTO WEST MISSISSIPPI THIS EVENING.
SHOWERS AND THUNDERSTORMS WILL TRACK TO THE NORTHEAST AHEAD OF
THE FRONT TODAY...PRODUCING SLOW MOVING BANDS OF RAIN THAT WILL
PERSIST OVER THE SAME AREA FOR AN EXTENDED AMOUNT OF TIME.
PERIODS OF HEAVY RAIN MAY RESULT IN STANDING WATER ON ROADWAYS
AND IN LOW LYING AREAS. MOTORISTS SHOULD EXERCISE CAUTION WHEN
APPROACHING STANDING WATER ON ROADS.

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