Severe Thunderstorm Warning 237, NWS Jackson, MS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
200 PM CDT SAT JUL 6 2002

MAIN FORECAST PROBLEM THIS AFTERNOON CONCERNS COVERAGE OF
CONVECTION NEXT FEW DAYS.

MODELS IN GENERAL AGREEMENT THAT UPPER RIDGE OVER MID MISSISSIPPI
VALLEY THIS MORNING WILL RETROGRADE NEXT SEVERAL DAYS AND EVENTUALLY
STRENGTHEN OVER INTERMOUNTAIN WEST.  MAIN MODEL DIFFERENCES CONCERN
HOW RAPIDLY THIS WILL OCCUR...AND WITH HANDLING OF WEAK SYSTEMS
RIDING DOWN EAST SIDE OF UPPER SYSTEM. HAVE GENERALLY WENT WITH AVN
THROUGH THE PERIOD AS IT GENERALLY HANDLES LARGE SCALE PATTERN BEST
WHEN SUBTROPICAL RIDGE SETS UP NORTH OF REGION. FURTHERMORE...ETA
SEEMS TO HAVE SOME PROBLEMS WITH STRONG CONVECTIVE BLOWUPS...
PARTICULARLY SUNDAY NIGHT INTO MONDAY.

LATEST SATELLITE IMAGERY/DERIVED SURFACE FIELDS SHOWING SHORT TERM
DEVELOPMENT MOST LIKELY OVER NE AND EAST CENTRAL ZONES WHERE BEST
CUMULUS/INSTABILITY LOCATED. DEEP MOISTURE RATHER LIMITED HERE SO
WHILE CONVECTION COULD BE INTENSE WITH MICROBURSTS POSSIBLE PER
LOCAL SCHEMES...COVERAGE LIKELY TO BE ISOLATED. CONVECTION MAY BE
HELPED ALONG TONIGHT BY DISTURBANCE WHICH AVN SHOWS DROPPING ACROSS
AREA FROM NE TO SW.

FOR SUNDAY...AVN BRINGS ANOTHER IN A SERIES OF DISTURBANCES
SOUTHWEST ACROSS REGION ON SE SIDE OF UPPER RIDGE. DEEPEST MOISTURE
STILL IN THE SOUTH...BUT AGAIN BEST LAPSE RATES/INSTABILITY TO
SUPPORT STRONG CONVECTION LIKELY TO BE IN THE NORTH. WILL GO WITH
ISOLATED POPS NORTH AND SCATTERED POPS SOUTH. BY MONDAY...AVN 250 MB
STREAMLINES SHOW UPPER RIDGE BECOMING MORE WEST/EAST ORIENTED ACROSS
MID MS/OHIO VALLEY REGIONS WITH DEEP EASTERLY FLOW ESTABLISHED
ACROSS REGION. MODEL HINTS AT EASTERLY WAVE PROGRESSING ACROSS AREA
WITH SURGE OF MOISTURE INTO EASTERN ZONES TO EAST OF WAVE AXIS. WILL
GO WITH SCATTERED POPS SOUTH AND EAST AND ISOLATED POPS OVER THE NW
ZONES.

IN LATER PERIODS...AVN 250 MB STREAMLINES SHOW WEST/EAST RIDGE RIGHT
ACROSS AREA TUE WITH BETTER MOISTURE SUPPRESSED TO THE SW. WILL GO
WITH ISOLATED STORMS. BY WEDNESDAY...RIDGE CONTINUES TO RETROGRADE
AND UPPER FLOW BECOMES NORTHWESTERLY ACROSS AREA. MODELS SHOW SOME
UNCERTAINTY ON STRENGTH OF SYSTEM DRIVING SE THROUGH GREAT LAKES/MS
VALLEY REGION LATE IN WEEK WITH ENSEMBLES AND 12Z AVN HINTING THAT
SYSTEM MAY BE STRONGER THAN SHOWN BY 00Z RUNS. IN ANY EVENT...SERIES
OF DISTURBANCES MOVING THROUGH NW FLOW WILL COMBINE WITH INCREASING
MOISTURE AHEAD OF FRONT DROPPING TOWARD AREA TO PRODUCE SCATTERED
SHOWERS AND THUNDERSTORMS WEDNESDAY THROUGH FRIDAY. STRONGER...MORE
NORTHERLY UPPER FLOW BEHIND SYSTEM PASSING THROUGH EASTERN STATES
MAY BE SUFFICIENT TO PUSH DEEPER MOISTURE FARTHER TO THE SOUTH BY
NEXT WEEKEND...RESULTING IN A SOMEWHAT REDUCED RISK OF CONVECTION.

AS FAR AS TEMPERATURES...ETA TEMPERATURES LOOK A BIT TOO WARM
THROUGH THE PERIOD AND HAVE WENT CLOSER TO AVN/NGM.

PRELIMINARY NUMBERS...
JAN 73/95/73/93/73 2323
MEI 72/94/73/93/72 2323

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

08

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
071200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
135 PM CDT SAT JUL 06 2002

...THUNDERSTORMS...
ISOLATED THUNDERSTORMS WILL BE POSSIBLE BETWEEN 3 PM AND 10 PM
ACROSS SOUTHEAST ARKANSAS...NORTHEAST LOUISIANA AND MUCH OF
MISSISSIPPI.  A FEW STORMS MAY BECOME SEVERE. THE BEST CHANCE OF
THUNDERSTORMS WILL BE SOUTH OF A RAYVILLE...LOUISIANA TO
VICKSBURG TO JACKSON TO MERIDIAN LINE...OR ROUGHLY SOUTH OF
INTERSTATE 20. THE OVERALL COVERAGE OF THUNDERSTORM ACTIVITY
SHOULD NOT BE WIDESPREAD TODAY AND MANY LOCATIONS WILL REMAIN DRY
THROUGH THE EVENING. HOWEVER...ANY STORM THAT DEVELOPS WILL HAVE
THE POTENTIAL TO PRODUCE DAMAGING DOWNBURST WINDS OF UP TO 60 MPH
AND UP TO QUARTER SIZED HAIL.

THE COMBINATION OF DAYTIME HEATING...AVAILABLE MOISTURE...AND AN
APPROACHING FRONTAL SYSTEM WILL RESULT IN ISOLATED TO SCATTERED
THUNDERSTORM DEVELOPMENT ACROSS SOUTHEAST ARKANSAS...EXTREME
NORTHEAST LOUISIANA...AND NORTHERN MISSISSIPPI THROUGH THIS
EVENING. A SLIGHTLY MORE MOIST AIRMASS ACROSS EAST-CENTRAL
LOUISIANA AND IN CENTRAL AND SOUTH MISSISSIPPI WILL ALLOW A
SLIGHTLY GREATER COVERAGE OF THUNDERSTORMS ACROSS THIS AREA SOUTH
OF INTERSTATE 20.  WITH A COLD FRONT FORECAST TO MOVE INTO A VERY
UNSTABLE AIRMASS ACROSS THE REGION...SOME STORMS MAY BECOME
SEVERE WITH LARGE HAIL AND DAMAGING DOWNBURST WINDS.

THE ACTIVATION OF STORM SPOTTERS AND EMERGENCY MANAGEMENT
PERSONNEL...IN SUPPORT OF SEVERE WEATHER OPERATIONS...SHOULD NOT
BE REQUIRED THROUGH TONIGHT.

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

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
071200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
141 PM CDT SAT JUL 06 2002

...THUNDERSTORMS...
ISOLATED TO SCATTERED THUNDERSTORMS WILL BE POSSIBLE BETWEEN 3 PM
AND 10 PM ACROSS SOUTHEAST ARKANSAS...NORTHEAST LOUISIANA AND
MUCH OF MISSISSIPPI. A FEW STORMS MAY BECOME SEVERE. THE BEST
CHANCE OF THUNDERSTORMS WILL BE SOUTH OF A RAYVILLE...LOUISIANA
TO VICKSBURG TO JACKSON TO MERIDIAN LINE...OR ROUGHLY SOUTH OF
INTERSTATE 20. THE OVERALL COVERAGE OF THUNDERSTORM ACTIVITY
SHOULD NOT BE WIDESPREAD TODAY AND MANY LOCATIONS WILL REMAIN DRY
THROUGH THE EVENING. HOWEVER...ANY STORM THAT DEVELOPS WILL HAVE
THE POTENTIAL TO PRODUCE DAMAGING DOWNBURST WINDS OF UP TO 60 MPH
AND UP TO QUARTER SIZED HAIL.

THE COMBINATION OF DAYTIME HEATING...AVAILABLE MOISTURE...AND AN
APPROACHING FRONTAL SYSTEM WILL RESULT IN ISOLATED TO SCATTERED
THUNDERSTORM DEVELOPMENT ACROSS SOUTHEAST ARKANSAS...EXTREME
NORTHEAST LOUISIANA...AND NORTHERN MISSISSIPPI THROUGH THIS
EVENING. A SLIGHTLY MORE MOIST AIRMASS ACROSS EAST-CENTRAL
LOUISIANA AND IN CENTRAL AND SOUTH MISSISSIPPI WILL ALLOW A
SLIGHTLY GREATER COVERAGE OF THUNDERSTORMS ACROSS THIS AREA SOUTH
OF INTERSTATE 20. WITH A COLD FRONT FORECAST TO MOVE INTO A VERY
UNSTABLE AIRMASS ACROSS THE REGION...SOME STORMS MAY BECOME
SEVERE WITH LARGE HAIL AND DAMAGING DOWNBURST WINDS.

THE ACTIVATION OF STORM SPOTTERS AND EMERGENCY MANAGEMENT
PERSONNEL...IN SUPPORT OF SEVERE WEATHER OPERATIONS...SHOULD NOT
BE REQUIRED THROUGH TONIGHT.

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