Severe Thunderstorm Warning 323, NWS Jackson, MS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
330 AM CDT WED MAY 3 2000

LATEST SURFACE ANALYSIS SHOWS STATIONARY BOUNDARY STRETCHING FROM
NEAR THE GA/SC BORDER AND UP THROUGH CENTRAL TX. DEWPOINTS OVER THE
SW CORNER OF THE STATE ARE IN THE UPPER 60S...WHILE ELSEWHERE THEY
RANGE FROM THE LOWER TO MID 60S. 88D SHOWING A LARGE AREA OF SHOWERS
AND THUNDERSTORMS MOVING EAST OVER CENTRAL LA AT THIS TIME.

MODELS ARE AGAIN IN FAIRLY GOOD AGREEMENT THIS RUN. HIGH PRESSURE
WILL STAY OFF TO OUR EAST. 500 MB LOW IN SOUTH CENTRAL OK WILL
CONTINUE TO MEANDER EAST ALONG THE TX/OK BORDER THROUGH LATE
THURSDAY. SLIGHT DIFFERENCES IN THE MODELS AGAIN OCCUR WITH THE
TIMING AND PLACEMENT OF SHORTWAVE ENERGY ROUNDING THE BASE OF THE
TROF IN TEXAS.

GULF MOISTURE WILL CONTINUE TO BE BROUGHT INTO THE REGION BY THE
SOUTHERLY/SOUTHEASTERLY WINDS WITH THE AXIS OF GREATEST MOISTURE
ALONG AND WEST OF THE MS RIVER.  THE GREATEST AMOUNTS OF INSTABILITY
WILL BE OVER THE SOUTHWESTERN ZONES...WHICH ARE CLOSEST TO THE COLD
POOL...AND EJECTING SHORTWAVES.  LI/S AVERAGE AROUND -3 TO -6 AND
CAPES RANGE ANYWHERE FROM 1000 TO 1500 J/KG. MAIN FOCUSING AGENT FOR
INITIATION OF CONVECTION WILL BE OLD OUTFLOW BOUNDARIES. IN
COORDINATING WITH KLIX...HAVE DECIDED TO  MENTION POSSIBILITY OF
SEVERE STORMS IN THE SOUTHWESTERN ZONES TODAY. SPC HAS THIS AREA IN
SLIGHT RISK.

WITH NO OTHER SPECIFIC FOCUSING AGENT OTHER THAN OLD
BOUNDARIES...WILL MENTION ONLY CHANCE POPS FOR THE LATTER TWO
PERIODS OF PACKAGE. LOOKING AT GUIDANCE...NUMBERS ARE FAIRLY CLOSE
AND WILL NOT STRAY TOO MUCH. HIGHEST POPS WILL BE IN THE WEST AND
DECREASE EASTWARD. TEMPS LOOK OK.

QPF DISCUSSION: SCATTERED SHOWERS AND STORMS IN NE CWFA WILL MOVE
OUT SOON. HOWEVER...MORE IMPULSES RIDE UP IN SWLY FLOW WITH A FEW
BOUNDARIES AROUND. AVN LOOKS BEST AMONGST MODELS ON QPF...YET
AMOUNTS LOOK TOO LIGHT WITH PRECIPITABLE WATERS INCHING TOWARDS 1.4
INCHES AND FAIRLY UNSTABLE ATMOSPHERE IN PLACE. WILL LEAN TOWARDS
MORE ROBUST HPC BASIN AMOUNTS WITH HIGHEST AMOUNTS WESTERN SECTIONS
(0.50-1.00)...TRENDING DOWN TOWARDS THE E/NE CWFA (0.10-0.25).
CONF:IDENCE WILL BE MARGINAL DUE LACKING LOW LEVEL FOCUS.

CURRENT EXTENDED LOOKS FINE.

JAN 79/64 81/62 6443
MEI 82/62 82/62 4332

.JAN...
MS...NONE.
AR...NONE.
LA...NONE.
32/05

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
040400-

AREA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
1020 AM CDT TUE MAY 2 2000

AN UPPER LEVEL LOW PRESSURE SYSTEM REMAINED OVER THE SOUTHERN PLAINS
...CENTERED OVER OKLAHOMA AND NORTH TEXAS. AT THE SURFACE...A NEAR-
STATIONARY BOUNDARY REMAINED STRETCHED FROM NORTH GEORGIA INTO
MISSOURI THIS MORNING. THE FOCUSING MECHANISM FOR SHOWERS AND
THUNDERSTORMS OVER THE LOWER MISSISSIPPI RIVER VALLEY HAS BEEN A
WEAK SURFACE TROUGH OF LOW PRESSURE THAT EXTENDED FROM NORTHWEST
MISSISSIPPI INTO SOUTHEAST LOUISIANA. THIS WEAK BOUNDARY WILL
GRADUALLY DRIFT EAST TODAY AS THE UPPER SYSTEM SLOWLY LIFTS
NORTHEAST TOWARD THE MIDDLE MISSISSIPPI RIVER VALLEY.

WITH ABUNDANT MOISTURE OVER THE REGION...LOCALLY HEAVY RAINFALL WILL
DEVELOP TODAY IN STRONGER THUNDERSTORMS...MAINLY OVER NORTHWEST
MISSISSIPPI. WEAK FRONTAL SUPPORT AND LIMITED WIND SHEAR WILL
PRECLUDE ORGANIZED SEVERE THUNDERSTORM ACTIVITY. HOWEVER...ENOUGH
INSTABILITY COULD EXIST TO SUPPORT ISOLATED SEVERE THUNDERSTORMS
DURING MAXIMUM HEATING IN THE LATE AFTERNOON AND EARLY EVENING. THE
PRIMARY SEVERE WEATHER THREAT WOULD BE LARGE HAIL AND DAMAGING
WINDS. IN AREAS WHERE RAINFALL HAS BEEN PERSISTENT...LOCALIZED
FLOODING COULD DEVELOP.

ACTIVATION OF STORM SPOTTERS...HAM RADIO OPERATORS...AND EMERGENCY
MANAGEMENT PERSONNEL IS NOT EXPECTED THROUGH TONIGHT.

FOR MORE INFORMATION...PLEASE VISIT OUR INTERNET WEB SITE AT
HTTP://WWW.SRH.NOAA.GOV/JAN