Severe Thunderstorm Warning 103, NWS Jackson, MS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
320 AM CDT MON APR 8 2002

A VERY ACTIVE WEATHER SITUATION IS EXPECTED FOR TODAY WITH POSSIBLE
SEVERE WEATHER...FLOODING...AND SUSTAINED WINDS NEAR 25 MPH.

A SEVERE THUNDERSTORM WATCH IS ALREADY IN EFFECT AT THIS TIME FOR
WESTERN SECTIONS OF THE FORECAST AREA. THE STORMS OCCURRING IN THE
CURRENT SEVERE THUNDERSTORM BOX SHOULD CONTINUE TO MOVE EASTWARD
ACROSS OUR FORECAST AREA TODAY. THE LINE OF STORMS MAY WEAKEN A BIT
AS THE STORMS ENTER MISSISSIPPI AS THE BEST UPPER LEVEL DIVERGENCE
IS FARTHER WEST. HOWEVER...THE 300 MB JET WILL SHIFT EASTWARD LATER
TODAY AND WILL SHIFT THE RIGHT ENTRANCE REGION OF THE JET TO THE
MISSISSIPPI RIVER BY THIS AFTERNOON. STORMS ARE LIKELY TO INTENSIFY
DURING THE AFTERNOON HOURS WITH THE STRONGEST STORMS AND HEAVIEST
RAINFALL GENERALLY ALONG AND WEST OF A EUPORA TO KOSCIUSKO TO
BRANDON TO BROOKHAVEN LINE. LOCATIONS EAST OF THIS LINE ARE STILL
LIKELY TO SEE GOOD COVERAGE OF RAINFALL TODAY AND INTO TONIGHT.
EXPECT SOME RAINFALL ACTIVITY WILL EVEN LINGER INTO TUESDAY EAST OF
THE MISSISSIPPI RIVER...ESPECIALLY IN SOUTHEASTERN SECTIONS.

WINDS ARE LIKELY TO BE STRONG TODAY ACROSS THE ENTIRE FORECAST AREA
AS THE REGION IS SQUEEZED BETWEEN A STRONG HIGH PRESSURE CENTER OFF
THE U.S. EAST COAST AND LOW PRESSURE TO THE WEST. WILL ISSUE A WIND
ADVISORY FOR TODAY ACROSS THE ENTIRE FORECAST AREA.

FOR FLOODING POTENTIAL...THE HPC HAS OUR ENTIRE FORECAST AREA IN AN
AREA OF POSSIBLE EXCESSIVE RAINFALL. AT THIS TIME...BELIEVE THE
STRONGEST THREAT FOR HEAVY RAINFALL IS IN MUCH OF THE WESTERN HALF
OF THE FORECAST AREA WHERE UPPER LEVEL JET SUPPORT SHOULD BE THE
GREATEST (GENERALLY WEST OF THE LINE MENTIONED IN FIRST PARAGRAPH
ABOVE). WILL ISSUE A FLOOD WATCH FOR TODAY FOR MUCH OF THE WESTERN
HALF OF OUR FORECAST AREA.

CONCERNING SEVERE POTENTIAL...THE FORECAST INSTABILITIES LOOK
SOMEWHAT MARGINAL FOR SEVERE WEATHER TODAY BUT ETA MODEL DOES
PREDICT AFTERNOON CAPE VALUES UP TO 1800 J/KG IN THE VICKSBURG AREA.
FORECAST SFC TO 3 KM HELICITY VALUES LOOK VERY FAVORABLE WITH
WIDESPREAD 400 TO 600 M2/S2 VALUES FOR THIS AFTERNOON. THE EXPECTED
POSITION OF THE RIGHT ENTRANCE REGION OF THE UPPER LEVEL JET OVER
THE MISSISSIPPI RIVER AREA BY THIS AFTERNOON WILL ALSO INCREASE THE
SEVERE POTENTIAL IN WESTERN SECTIONS. WILL MENTION SEVERE FOR ALL
LOCATIONS MENTIONED IN THE FLOOD WATCH AREA. EASTERN SECTIONS COULD
ALSO SEE SOME STRONG STORMS BUT WILL LEAVE OUT MENTION OF SEVERE AT
THIS TIME.

THE WEATHER SYSTEM WILL BE SLOW TO MAKE EASTWARD PROGRESS TONIGHT.
OUR SOUTHEASTERN SECTIONS WILL SEE BULK OF THE RAINFALL FOR THIS
EVENT TONIGHT AND EARLY TUESDAY. EXPECT WEDNESDAY TO BE DRY.

EXPECT MILD TEMPERATURES FOR THE PERIOD...ESPECIALLY MILD TONIGHT AS
STRONG SOUTHERLY WINDS KEEP TEMPERATURES IN THE 60S. MINIMUMS SHOULD
DROP INTO THE 50S FOR TUESDAY NIGHT. DAYTIME HIGH TEMPERATURES
SHOULD GENERALLY BE IN THE 70S THROUGH THE PERIOD. WILL STAY CLOSE
TO AVN/NGM GUIDANCE NUMBERS WHICH ARE CONSISTENT WITH EACH OTHER AND
WHICH APPEAR TO HAVE REASONABLE NUMBERS.

IN THE EXTENDED (THURSDAY THROUGH SUNDAY)...WILL KEEP MENTION OF
CHANCE OF SHOWERS IN FORECAST FOR FRIDAY THROUGH SUNDAY...BUT SO FAR
DOES NOT LOOK LIKE ANY MAJOR RAINFALL EVENTS ON THE HORIZON.
TEMPERATURES SHOULD BE SEASONABLY MILD.

THANKS TO NWS KNEW...KMOB...AND KMEM FOR COORD.

PRELIM NUMBERS...
JAN 076/065 077/058 075 +86-0
MEI 077/065 074/056 075 78710

.JAN...
AR...FLOOD WATCH FOR TODAY AND WIND ADVISORY FOR TODAY...EXTREME
SOUTHEAST AR ZONES.
LA....FLOOD WATCH FOR TODAY AND WIND ADVISORY FOR TODAY IN NORTHEAST
LA ZONES
MS...WIND ADVISORY FOR TODAY FOR ALL THE KJAN MS ZONES. FLOOD WATCH
FOR TODAY FOR ALL KJAN ZONES ALONG AND WEST OF EUPORA TO KOSCIUSKO
TO BRANDON TO BROOKHAVEN LINE.

15

WATCH NOTIFICATION FOR SEVERE THUNDERSTORM WATCH 78
NATIONAL WEATHER SERVICE JACKSON MS
445 AM CDT MON APR 8 2002

ARZ074-075-LAZ007>009-015-016-023>025-MSZ018-019-034-081100-
THE NATIONAL WEATHER SERVICE IN JACKSON HAS CANCELED A PORTION OF
SEVERE THUNDERSTORM WATCH 78. COUNTIES AND PARISHES CANCELED INCLUDE:

IN SOUTHEAST ARKANSAS:
ASHLEY...CHICOT...

IN NORTHEAST LOUISIANA:
MOREHOUSE...WEST CARROLL...EAST CARROLL...RICHLAND...MADISON LA...
FRANKLIN LA...TENSAS...CATAHOULA...

IN NORTH MISSISSIPPI:
BOLIVAR...SUNFLOWER...WASHINGTON...

THIS INCLUDES THE CITIES OF...BASTROP...CLEVELAND...CROSSETT...
GREENVILLE...HARRISONBURG...INDIANOLA...LAKE PROVIDENCE...
LAKE VILLAGE...OAK GROVE...RAYVILLE...ST JOSEPH...TALLULAH...
WINNSBORO...

LAZ026-MSZ025-035-040-041-047-053-059-060-081100-
SEVERE THUNDERSTORM WATCH 78 REMAINS IN EFFECT UNTIL 600 AM CDT
MONDAY FOR THE FOLLOWING COUNTIES AND PARISHES:

IN NORTHEAST LOUISIANA:
CONCORDIA...

IN NORTH MISSISSIPPI:
LEFLORE...

IN CENTRAL MISSISSIPPI:
HUMPHREYS...ISSAQUENA...SHARKEY...WARREN...CLAIBORNE...JEFFERSON...

IN SOUTH MISSISSIPPI:
ADAMS...

THIS INCLUDES THE CITIES OF...BELZONI...FAYETTE...GREENWOOD...
MAYERSVILLE...NATCHEZ...PORT GIBSON...ROLLING FORK...VICKSBURG...
VIDALIA...

WATCH NOTIFICATION FOR SEVERE THUNDERSTORM WATCH 78...UPDATED
NATIONAL WEATHER SERVICE JACKSON MS
529 AM CDT MON APR 8 2002

LAZ026-MSZ025-035-040-041-047-053-059-060-081100-
THE NATIONAL WEATHER SERVICE IN JACKSON HAS CANCELED ALL COUNTIES
AND PARISHES IN SEVERE THUNDERSTORM WATCH 78. COUNTIES AND PARISHES
CANCELED INCLUDE:

IN NORTHEAST LOUISIANA:
CONCORDIA...

IN NORTH MISSISSIPPI:
LEFLORE...

IN CENTRAL MISSISSIPPI:
HUMPHREYS...ISSAQUENA...SHARKEY...WARREN...CLAIBORNE...JEFFERSON...

IN SOUTH MISSISSIPPI:
ADAMS...

THIS INCLUDES THE CITIES OF...BELZONI...FAYETTE...GREENWOOD...
MAYERSVILLE...NATCHEZ...PORT GIBSON...ROLLING FORK...VICKSBURG...
VIDALIA...