Hail and Damaging Wind in Louisiana, June 24, 2002

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
235 PM CDT MON JUN 24 2002

FORECAST ISSUES TODAY ABOUT SAME AS PAST SEVERAL DAYS. FORECAST
REVOLVES AROUND PROGRESS OF UPPER-LEVEL LOW PRESSURE SYSTEM ACROSS
LA/CLOUD COVER/AMOUNT OF RAIN WITH SYSTEM. ANOTHER PROBLEM TODAY/TUE
IS POTENTIAL FOR ISOLATED SEVERE STORMS. IN THE EXTENDED...PROBLEM
WILL BE RAIN CHANCES WITH REMNANTS OF UPPER-LEVEL SYSTEM.

STACKED UPPER-LEVEL COLD CORE LOW STILL CENTERED WEST OF KBTR.
AIRMASS SATURATED UP THROUGH 250 MB...IN SUSTAINED SE TO S FLOW. 12Z
PRECIP WATER VALUES RANGED BETWEEN 1.75 AND 2. AT 1830Z...SURFACE
DEWPOINTS RANGED FROM MID 60S TO LOWER 70S OVER REGION. BETTER
INSOLATION/TEMPS WARMER THAN SUN ALLOWED AIRMASS TO DESTABILIZE MORE
RAPIDLY. LIS ALREADY -6 TO -8 OVER AREA. FROM 12Z RAOBS...CAPE
VALUES OVER LOWER MS RIVER VALLEY RANGED FROM 2500 J/KG TO OVER 3000
J/KG AT KJAN...WITH AFTERNOON CAPES APPROACHING 4000 J/KG POSSIBLE.
FREEZING LEVEL ONLY AROUND 12K. IN ALL...EXPECT BETTER THUNDERSTORM
DEVELOPMENT THIS AFTERNOON/EVENING...WITH AN ISOLATED SEVERE STORM
POSSIBLE WILL NOT MENTION SEVERE IN ZONES. GIVEN DEEP MOISTURE...AN
EFFICIENT STORM COULD PRODUCE BRIEF HEAVY RAINFALL.

MODEL SCENARIOS STILL CONVERGE ON SOLUTION OF UPPER LOW SHIFTING
INTO NW LA TONIGHT. UPPER LOW THEN MOVES WEST INTO ARLATX BY 12Z
TUE. EARLIER MODEL RUNS TOOK UPPER LOW NORTH INTO SW AR. SEVERAL
WEAK SHORTWAVES WILL RIPPLE THROUGH RELATIVELY WEAK MID-/UPPER-LEVEL
FLOW. IN PROGS...DEWPOINTS/PRECIP WATER VALUES/LOWER-LEVEL RELATIVE
HUMIDITIES ALL REMAIN HIGH. YET...AVN/ETA BOTH ENTRAIN SIGNIFICANTLY
DRIER AIR OVER CWFA FROM EAST AT MID-/UPPER-LEVELS BY 12Z TUE.

FROM 12Z TUE ON...MODELS BEGIN TO DIFFER. ETA DEVELOPS SURFACE HIGH
PRESSURE AREA OVER NRN GULF MX. ETA ALSO OPENS CLOSED LOW PRESSURE
CENTER BY 06Z WED OVER ARLATX. COMBINATION OF THESE DEVELOPMENTS
APPEAR TO DIMINISH SUPPORT FOR PRECIP OVER CWFA TUE/WED IN ETA.
PRESENCE OF DRIER AIR COULD MEAN LESS CLOUDINESS (MAINLY ERN ZONES).
OVERALL..PREFER AVN SOLUTION WHERE LOW PRESSURE SYSTEM REMAINS
CLOSED OVER ARLATX THROUGH 18Z WED/MAIN TROUGH AXIS PERSISTS JUST
WEST OF CWFA.

GIVEN DIURNAL HEATING OF BASICALLY TROPICAL AIRMASS/ANY MESO-SCALE
BOUNDARIES THAT MIGHT DEVELOP/WEAK SHORTWAVES RIPPLING OVER CWFA...
EXPECT SCATTERED CONVECTION OVER THROUGH WED. WITH MORE INSOLATION/
MORE INSTABILITY/STEEPER TEMP LAPSE RATES...COULD MAKE ARGUMENT
FOR ISOLATED SEVERE STORMS TUE...ESPECIALLY ERN ZONES.

FROM WED THROUGH NEXT MON...AVN/MRF/NOGAPS SOLUTIONS KEEP WEAKENED
UPPER LOW PRESSURE REMNANTS AROUND ARLATX...WITH ABUNDANT MOISTURE
OVER LOWER MS RIVER VALLEY. UPPER-LEVEL/SURFACE HIGH PRESSURE
DEVELOPS OVER WRN STATES...THOUGH IMPACTS WILL NOT BE FELT OVER
CWFA. BY 12Z SAT...SOME SLIGHTLY DRIER AIR PUSHES INTO REGION FROM
EAST IN CIRCULATION AROUND DEVELOPING HIGH PRESSURE AREA OVER GA/FL.
HOWEVER...NO MAJOR WEATHER SYSTEM APPROACHES CWFA TO SCOUR AIRMASS
OF MOISTURE. GIVEN PERSISTENT SOGGY AIRMASS..EXPECT PARTLY CLOUDY
SKIES WITH SOME DIURNAL CONVECTION EACH DAY. LOCALLY HEAVY RAINFALL
COULD DEVELOP THROUGH EXTENDED.

WILL TREND TOWARDS AVN GUID VALUES. DAYTIME TEMPS GENERALLY IN 80S.
OVERNIGHT LOW GENERALLY IN 60S TO LOWER 70S. CURRENT MODEL SOLUTIONS
INDICATE PERSISTENCE WILL BE BEST FORECAST THROUGH MON.

PRELIMINARY NUMBERS
JAN 68/88/69/87/70  35353
MEI 67/89/68/87/69  34352

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

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
251200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
203 PM CDT MON JUN 24 2002

...THUNDERSTORMS...
SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE THIS AFTERNOON
AND EVENING OVER PORTIONS OF NORTHEAST LOUISIANA...SOUTHEAST
ARKANSAS AND MUCH OF MISSISSIPPI. SEVERE STORMS ARE NOT
EXPECTED...HOWEVER...A FEW STORMS MAY PRODUCE WIND GUSTS TO 45
MPH AND SMALL HAIL MAINLY WEST OF THE MISSISSIPPI RIVER.

AN UPPER LEVEL LOW PRESSURE SYSTEM WILL CONTINUE TO REMAIN NEARLY
STATIONARY TONIGHT OVER CENTRAL PORTIONS OF LOUISIANA. MOIST
SOUTHERLY FLOW AND  DAYTIME HEATING WILL COMBINE WITH THE UPPER
LEVEL SYSTEM TO CONTINUE PRODUCING SHOWERS AND THUNDERSTORMS OVER
MUCH OF THE AREA THIS AFTERNOON AND EVENING. ACTIVITY SHOULD
BEGIN DECREASING AFTER SUNSET...BUT A FEW STORMS COULD LINGER
OVERNIGHT AS THE UPPER LOW CONTINUES TO PROVIDE UPPER LEVEL
INSTABILITY TO SUSTAIN SOME SHOWER AND THUNDERSTORM DEVELOPMENT.

THE ACTIVATION OF STORM SPOTTERS...HAM RADIO...AND EMERGENCY
MANAGEMENT PERSONNEL FOR SEVERE WEATHER OPERATIONS...IS NOT
ANTICIPATED THROUGH TONIGHT.

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