Severe Thunderstorm Warning 587, NWS Jackson, MS

FXUS64 KJAN DDHHMM
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
140 PM CDT SAT AUG 26 2000

LOOKING AT VAPOR IMAGERY UPPER RIDGE WAS STILL PREVALENT...AS
ANOTHER WELL DEFINED SHORTWAVE...WHICH WAS ADVERTISED BY THE MODELS
WAS MOVING OVER THE EASTERN SECTIONS OF THE FORECAST AREA. ON THE
SURFACE A WEAK FRONT WAS NOTED ACROSS THE REGION WITH DEWPOINTS IN THE
60S AND 70S.

LOOKING AT THE SHORTTERM RANGE THE UPPER RIDGE WILL MAINTAIN ITSELF
THROUGH THE PERIOD...WITH A SERIES OF WEAK SHORTWAVES PASSING
THROUGH THE REGION ON THE EASTERN SIDE OF THE RIDGE. SLIGHTLY COOLER
MID LEVEL TEMPS AND TIME OF MAX AFTERNOON HEATING WILL FAVOR MORE
ROUNDS OF AFTERNOON AND EARLY EVENING THUNDERSTORMS THROUGH MONDAY.
ALSO A BACK DOOR FRONT WILL BE HANGING ACROSS THE REGION TONIGHT...BEFORE
RETREATING BACK TO THE EAST OF THE REGION ON SUNDAY.THE FRONT WILL
PROVIDE SOME ADDED LOW LEVEL CONVERGENCE THROUGH TONIGHT...WHICH
WILL MAKE POPS A LITTLE DIFFICULT...DEPENDING ON FRONTAL
POSITIONING. MEAN MOISTURE WILL BE DECENT OVER THE REGION DURING THE
PERIOD. SO WITH THAT IN MIND WILL FOLLOW THE ETA SOLUTION...SINCE IT
INTIALIZED THE SURFACE AND UPPER FEATURES THE BEST.

THE BEST COVERAGE FOR TONIGHT SHOULD BE IN THE EAST AND SOUTH WITH
THE WEAK FRONT AND SEABREEZE AFFECTS TO CONTEND WITH ON POP COVERAGE.
ON SUNDAY...WHEN THE FRONT RETREATS EAST OF THE REGION...WILL PUT
THE BEST LOW POPS IN THE SOUTH FOR SEABREEZE INTERACTION...AS WELL
AS ON MONDAY. AS FAR AS TEMPERATURES ARE CONCERN WILL GO WITH THE COMBO
OF THE WARMER ETA/NGM MOS GUIDANCE.

24 HOUR QPF DISCUSSION: MODEL QPF FORECASTS AND NCEP GUIDANCE FOR
NEXT 24 HOURS PROBABLY A LITTLE ON THE LOW SIDE...ESPECIALLY FOR THE
EASTERN AND SOUTHERN PORTIONS OF THE CWA. STORMS ARE EXPECTED TO
DEVELOP IN THOSE AREAS AHEAD OF THE WEAK SURFACE BOUNDARY EARLY THIS
AFTERNOON AND CONTINUE THROUGH THIS EVENING. BASIN AVERAGE RAINFALL
OF ONE QUARTER INCH WITH HIGHER AMOUNTS LOCALLY ARE POSSIBLE.

EXTENDED DISCUSSION...LOOKING AT THE LONGTERM TUESDAY THROUGH
THURSDAY...UPPER RIDGE WILL BE PREVALENT ACROSS THE REGION THROUGH
THE PERIOD. THE MRF BRINGS A SLIGHT WEAKNESS TO THE RIDGE WEDNESDAY
NIGHT INTO THURSDAY...AS TROPICAL MEAN MOISTURE(REMNANTS OF DEBBY)
MOVES INTO THE REGION. ON THE SURFACE CONVECTIVE ACTIVITIY FROM THE
TROPICAL SYSTEM MOVES OVER THE REGION DURING THAT TIME...WHICH IS
CONSISTENT WITH ITS PREVIOUS RUN. LOOKING AT DEBBYS CURRENT TROPICAL
SITUATION...IT DOESNT SEEM LIKELY AT THIS TIME...SINCE STEARING
CURRENTS SHOULD TAKE IT WELL SOUTH OF THE REGION. IN THE LOW LEVELS
THE REGION WILL BE UNDER EAST SOUTHEAST FLOW. THE CANADIAN MODELS
HAS A LITTLE STRONGER UPPER RIDGE OVER THE REGION AND TAKES THE
REMNANTS OF DEBBY TO OUR SOUTH OVER THE GULF. THE NOGAPS MODEL WAS
NOT AS STRONG WITH THE UPPER RIDGE. LIKE THE CANADIAN MODEL IT KEEPS
THE MOISTURE FROM THE REMNANTS OF DEBBY IN THE GULF...BUT THE
CANADIAN WAS FARTHER SOUTH WITH IT...WHICH SEEMS REASONABLE. IT DID
SHOW SOME LIGHT CONVECTIVE COVERAGE IN THE SOUTH HALF...MAINLY DUE
TO SEA BREEZE INTERACTION. SO WITH THAT IN MIND WILL CONTINUE
ISOLATED CONVECTION NORTH/CENTRAL AND WIDELY SCATTERED CONVECTION
SOUTH FOR THE PERIOD.

PRELIM NUMBERS...
JAN 71/101/71/101 121
MEI 68/101/68/101 232

.JAN...
AR...NONE.
LA...NONE.
MS...NONE.
17/19