Severe Thunderstorm Warning 496, NWS Jackson, MS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
330 AM CDT TUE AUG 1 2000

NO SIGNIFICANT CHANGES EXPECTED IN LARGE SCALE PATTERN TODAY. UPPER
TROUGH PERSISTS OVER THE REGION WITH A SURFACE BOUNDARY LOCKED IN
THE VICINITY OF THE MS RIVER DELTA. AIR MASS CURRENTLY MOIST AT MID
LEVELS ACROSS THE AREA WITH SURFACE DEWPOINTS FROM THE UPPER 60S TO
LOWER 70S.

ANALYSIS SHOWS PRECIPITABLE WATER VALUES FROM 1.6 AT LIT TO 1.9 AT
NEW....WITH DRIER VALUES TO THE W. MODELS INDICATING AIR MASS TO BE
DRIER TODAY AS DRIER AIR IS ADVECTED INTO THE AREA FROM THE W. WATER
VAPOR PIX SHOW HINTS OF DRY AIR ADVECTION ACROSS NW LA AND SW AR.
WILL MAINTAIN CHANCE OF THUNDERSTORMS WITH BEST POPS ERN AND SERN
AREAS. ADMIT LOW CONFIDENCE SINCE MODELS MISSED MID LEVEL MOISTURE
MONDAY.

UPPER TROUGH FORECAST TO SHIFT EWD WED. SERIES OF SHORTWAVES...WITH
GOOD MID LEVEL COLD POCKETS...PROGGED TO MOVE IN FROM THE SW AND NW
BUT LITTLE OR NO REFLECTION IN MODEL PRECIP OR UVV FIELDS. BOUNDARY
BEGINNING TO WASH OUT WED AS ASSOCIATED LOW PRESSURE LIFTS TO THE NE.
BEST MOISTURE FORECAST TO REMAIN OVER SERN ZONES THROUGH WED. WITH
VERY LITTLE CONFIDENCE IN THE MODEL PERFORMANCE OF LATE...WILL
FOLLOW PERSISTENCE AND KEEP CHANCE OF THUNDERSTORMS MOST AREAS FOR
WEDNESDAY. AIR MASS TO REMAIN RELATIVELY UNSTABLE DUE TO PRESENCE OF
UPPER TROUGH. MAIN FORECAST PROBLEM WILL BE DISTRIBUTION OF MOISTURE
FIELD.

IN EXTENDED...MODELS PULLING BACK ON TROPICAL WAVE DEVELOPMENT
EARLIER ADVERTISED FOR LATE IN THE WEEK. UPPER TROUGHINESS TO REMAIN
OVER REGION THROUGH END OF WEEK SO THUNDERSTORM CHANCE IN CURRENT
FORECAST LOOKS REASONABLE.

QPF DISCUSSION: ANOTHER DIFFICULT QPF FORECAST FOR THE NEXT 24
HOURS. A WEAK TROUGH IS FORECAST TO CONTINUE TO BE IN PLACE ACROSS
THE FORECAST AREA TODAY. MOST PRECIPITATION WILL...AS USUAL FOR THIS
TIME OF YEAR..OCCUR IN AFTERNOON AND EARLY EVENING HOURS. IT'S HARD
TO PINPOINT SPECIFIC AMOUNTS FOR THIS FORECAST BECAUSE MODEL
GUIDANCE IS VERY INCONSISTENT. WILL GENERALLY KEEP SIX HOUR AMOUNTS
AT LESS THAN TWO TENTHS...WITH HIGHEST AMOUNTS IN SOUTHEAST AND
DURING THE PERIOD ENDING AT 00Z.

PRELIM NUMBERS...
JAN 91/70/90/69 4232
MEI 91/70/90/69 5342

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

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
020300-

AREA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
1000 AM CDT TUE AUG 1 2000

A SURFACE TROUGH WILL REMAIN SITUATED NEAR THE MISSISSIPPI RIVER WHILE
A SEABREEZE BOUNDARY IS EXPECTED TO MOVE NORTH FROM THE GULF COAST
DURING THE AFTERNOON HOURS. THESE BOUNDARIES COMBINED WITH DAYTIME
HEATING AND AMPLE LOW LEVEL MOISTURE WILL ACT AS A FOCUS FOR
SCATTERED SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND EARLY
EVENING. THE BEST CONCENTRATION OF SHOWERS AND STORMS SHOULD OCCUR
SOUTH OF INTERSTATE 20 AND EAST OF INTERSTATE 55 DURING THIS TIME.

WIDESPREAD SEVERE THUNDERSTORMS IS NOT EXPECTED. HOWEVER...ISOLATED
STRONGER STORMS WILL HAVE THE POTENTIAL TO PRODUCE DAMAGING WIND
GUSTS LATER TODAY.

ACTIVATION OF STORM SPOTTERS...HAM RADIO OPERATORS...AND EMERGENCY
MANAGEMENT PERSONNEL SHOULD NOT BE NECESSARY THROUGH TONIGHT.

FOR MORE INFORMATION PLEASE VISIT OUR INTERNET WEB SITE AT
WWW.SRH.NOAA.GOV/JAN (ALL IN LOWER CASE LETTERS). THIS INCLUDES AN
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK.