

000 

WWUS20 KWNS 141211

SEL0

SPC WW 141211

LAZ000-MSZ000-141800-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 140

NWS STORM PREDICTION CENTER NORMAN OK

710 AM CDT SAT APR 14 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHEAST LOUISIANA

       CENTRAL MISSISSIPPI



EFFECTIVE THIS SATURDAY MORNING AND AFTERNOON FROM 710 AM UNTIL

100 PM CDT.



HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70

MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 60

STATUTE MILES EAST AND WEST OF A LINE FROM 15 MILES WEST OF

COLUMBUS MISSISSIPPI TO 20 MILES EAST SOUTHEAST OF BATON ROUGE

LOUISIANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).



REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE

FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH

AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR

THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS

AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY

DO PRODUCE TORNADOES.



OTHER WATCH INFORMATION...CONTINUE...WW 139...



DISCUSSION...BROKEN FRONTAL SQUALL LINE CONTINUES TO MOVE EWD FROM

LA INTO WRN MS...WHILE ADDITIONAL PRE-FRONTAL STORMS ARE FORMING IN

SE LA.  GRADUAL LOW-LEVEL MOISTENING ACROSS SE LA AND SRN/CENTRAL MS

IS HELPING TO MAINTAIN AT LEAST WEAK SURFACE-BASED INSTABILITY...AND

ADDITIONAL DESTABILIZATION IS EXPECTED LATER THIS MORNING.

ALSO...LOCAL VWP/S SHOW LARGELY UNIDIRECTIONAL PROFILES WITH STRONG

SPEED SHEAR THROUGH THE MID LEVELS...WHICH SUGGESTS THAT THE PRIMARY

SEVERE STORM THREATS IN THE SHORT TERM WILL BE DAMAGING WINDS AND

LARGE HAIL WITH STORMS EMBEDDED IN THE LINE.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM

MOTION VECTOR 24035.





...THOMPSON

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