Severe Thunderstorm Warning 4, NWS Jackson, MS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
205 AM CST FRI FEB 20 2002

...FORECAST CONCERNS REMAIN THE AMOUNT OF RAINFALL TODAY AND THE
SEVERE WEATHER EVENT SHAPING UP FOR TONIGHT...

LOCAL 88-DS ARE ALREADY LIT UP THIS MORNING WITH MODERATE RAIN
FALLING ACROSS THE WHOLE CWA. THE HEAVIEST RAIN WAS STILL SOUTHWEST
OF THE CWA ACROSS CENTRAL LOUISIANA ASSOCIATED WITH THE
THUNDERSTORMS THAT WILL BE MOVING INTO SOUTHWEST MISSISSIPPI SHORTLY.
THE THUNDERSTORMS ARE EXPECTED TO SPREAD ACROSS THE CWA TODAY AS THE
WARM FRONT CURRENTLY ACROSS SOUTHERN MISSISSIPPI LIFTS BACK TO THE
NORTH. WITH 24-HR QPF AMOUNTS AROUND 2 INCHES AND LOCAL AMOUNTS OF
THREE TO FOUR INCHES POSSIBLE ACROSS THE WHOLE CWA THROUGH TONIGHT
WL EXPAND THE FLOOD WATCH TO ENCOMPASS THE WHOLE CWA.

THE MAIN EVENT IS STILL SLATED FOR TONIGHT AS THE UPPER LOW OVER OLD
MEXICO THIS MORNING APPROACHES OUR AREA AND HELPS DEEPEN THE LOW
ALREADY FORMING OFF THE SOUTHEAST TEXAS COAST. THE SFC LOW WILL
TRACK TO THE NORTHEAST ACROSS THE DELTA REGION. FAVORABLE
DYNAMICS...ABUNDANT MOISTURE AND ENOUGH INSTABILITY ARE EXPECTED TO
COME TOGETHER TONIGHT TO PRODUCE A SQUALL LINE THAT WILL MOVE ACROSS
THE CWA TONIGHT. SPC HAS OUTLOOKED OUR AREA IN A MODERATE RISK OF
SEVERE STORMS GENERALLY SOUTH OF A LINE FROM VICKSBURG TO GRENADA
WITH A SLIGHT RISK ELSEWHERE. WRAP AROUND RAIN IS EXPECTED TO
CONTINUE ACROSS THE NORTHERN COUNTIES SATURDAY BUT THE POTENTIAL FOR
SEVERE WEATHER SHOULD BE EAST OF OUR COUNTIES BY NOON. SUNDAY STILL
LOOKS DRY BUT A SECOND COLD FRONT WILL MOVE ACROSS THE AREA SUNDAY
NIGHT AND SQUEEZE OUT SOME MORE RAIN. COOLER AND DRIER WEATHER WILL
FOLLOW THROUGH MID WEEK.

PRELIM NUMBERS...

JAN 69/53/58/40/67 ++401
MEI 69/55/60/38/67 ++501

.JAN...
AR...FLOOD WATCH TONIGHT THROUGH FRIDAY NIGHT ALL ZONES SE AR.
LA...FLOOD WATCH TONIGHT THROUGH FRIDAY NIGHT ALL ZONES NE LA.
MS...FLOOD WATCH TONIGHT THROUGH FRIDAY NIGHT ALL ZONES.

22

ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074-
221200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSON MS
0435 AM CST FRI FEB 21 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL MISSISSIPPI...
NORTHEAST LOUISIANA...AND EXTREME SOUTHEAST ARKANSAS

.DAY ONE...TODAY AND TONIGHT...

...THUNDERSTORMS...
A MODERATE RISK OF SEVERE THUNDERSTORMS EXIT FOR LATE THIS
AFTERNOON INTO TONIGHT FOR EASTERN LOUISIANA INTO MOST OF
MISSISSIPPI...GENERALLY ALONG AND SOUTH OF A LINE FROM JONESVILLE
LOUISIANA TO YAZOO CITY TO COLUMBUS MISSISSIPPI. THERE IS A
SLIGHT RISK OF SEVERE THUNDERSTORMS NORTH OF THIS LINE.
THUNDERSTORMS ARE EXPECTED TO BE WIDESPREAD THIS MORNING THROUGH
EARLY THIS AFTERNOON...BUT NO ORGANIZED SEVERE WEATHER IS
EXPECTED BEFORE 5 PM.

A COMPLEX OF STORMS WAS MOVING OVER THE REGION THIS MORNING...BUT
IS EXPECTED TO TAPER OFF FROM THE WEST BY EARLY THIS AFTERNOON.

REDEVELOPMENT IS EXPECTED BY LATE THIS AFTERNOON AS A STRONG
STORM SYSTEM HEADS TOWARD THE LOWER MISSISSIPPI RIVER VALLEY.
THIS WILL LIKELY TRIGGER WIDESPREAD THUNDERSTORMS LATE THIS
AFTERNOON THROUGH TONIGHT. AS THUNDERSTORMS STRENGTHEN OVER THE
REGION TONIGHT...A LINE OF STRONG STORMS IS EXPECTED TO DEVELOP
BEFORE MIDNIGHT AND SWEEP THROUGH THE REGION BEFORE 6 AM
SATURDAY. THESE STORMS MAY BECOME SEVERE...WITH DAMAGING WIND
GUSTS OVER 70 MPH AND ISOLATED TORNADOES...ESPECIALLY SOUTHEAST
OF THE NATCHEZ TRACE PARKWAY.

THIS STORM SYSTEM LIFTING INTO THE SOUTHERN PLAINS AND LOWER
MISSISSIPPI VALLEY WILL COMBINE WITH ABUNDANT MOISTURE AND
INSTABILITY FROM THE GULF OF MEXICO TO PRODUCE WIDESPREAD
THUNDERSTORMS ACROSS SOUTHEAST ARKANSAS...NORTHEAST
LOUISIANA...AND MUCH OF MISSISSIPPI. AS THE CORE OF THE STORM
APPROACHES OUR AREA LATE THIS AFTERNOON...A SURFACE LOW PRESSURE
SYSTEM IS FORECAST TO INTENSIFY OVER LOUISIANA AND MOVE INTO
MISSISSIPPI IN ROUTE TO THE TENNESSEE VALLEY.

...FLOODING...
PERIODS OF HEAVY RAINFALL WILL BE LIKELY THIS MORNING AS WELL AS
LATE THIS AFTERNOON THROUGH TONIGHT OVER THE ENTIRE REGION. STORM
TOTAL RAINFALL AMOUNTS OF 2 TO 4 INCHES CAN BE EXPECTED. AREAS
WHERE THUNDERSTORMS CROSS OVER FOR AN EXTENDED PERIOD OF TIME
COULD GET ISOLATED AMOUNTS UP TO 5 INCHES. THE SOIL IS AT
SATURATION AND ANY FURTHER RAINFALL WILL CAUSE RAPID RUNOFF AND
LOCALIZED FLOODING PROBLEMS...ESPECIALLY IN LOW LYING AND POOR
DRAINAGE AREAS ACROSS THE ENTIRE REGION.

THIS WILL BE DUE TO AN APPROACHING INTENSIFYING AREA OF LOW
PRESSURE...WHICH WILL OPEN UP THE GULF FOR WIDESPREAD SHOWERS AND
THUNDERSTORMS TO REDEVELOP LATE THIS AFTERNOON THROUGH TONIGHT.

...NON PRECIPITATION...
AN INTENSE AREA OF LOW PRESSURE WILL APPROACH THE REGION FROM THE
SOUTHERN PLAINS THIS AFTERNOON. THE AREA OF LOW PRESSURE WILL
DEEPEN AS IT CROSSES LOUISIANA INTO MISSISSIPPI THIS EVENING.
SOUTHERLY WINDS WILL INCREASE FROM 10 TO 15 MPH TO 15 TO 25 MPH
FOR THIS EVENING...GENERALLY ALONG AND SOUTH OF INTERSTATE 20 AND
EAST OF INTERSTATE 55. THIS WILL CREATE ROUGH BOATING CONDITIONS
ON AREA LAKES.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY...

...DAYS TWO AND THREE...
NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

...DAYS FOUR THROUGH SEVEN...
NO HAZARDOUS WEATHER IS EXPECTED SUNDAY THROUGH WEDNESDAY.

.SPOTTER CALL TO ACTION STATEMENT...
THE ACTIVATION OF EMERGENCY MANAGEMENT PERSONNEL...STORM
SPOTTERS...AND HAM RADIO OPERATORS IN SUPPORT OF SEVERE WEATHER
MAY BE NEEDED LATE THIS AFTERNOON THROUGH TONIGHT.

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