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669 

WWUS20 KWNS 101146

SEL9

SPC WW 101146

LAZ000-MSZ000-CWZ000-101700-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 679

NWS STORM PREDICTION CENTER NORMAN OK

545 AM CST MON DEC 10 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       PARTS OF SOUTH CENTRAL AND SOUTHEAST LOUISIANA

       SOUTHWEST AND SOUTH CENTRAL MISSISSIPPI

       COASTAL WATERS



EFFECTIVE THIS MONDAY MORNING FROM 545 AM UNTIL 1100 AM CST.



TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS

TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 55 STATUTE

MILES EAST AND WEST OF A LINE FROM 55 MILES NORTH OF PINE BELT

MISSISSIPPI TO 15 MILES SOUTH SOUTHEAST OF INTRACOASTAL CITY

LOUISIANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).



REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR

TORNADOES AND 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.



DISCUSSION...THUNDERSTORMS CONTINUE TO DEVELOP ALONG A PRE-FRONTAL

CONFLUENCE BAND FROM S CENTRAL LA INTO SW MS...WHERE A FEW ROTATING

STORMS HAVE BEEN NOTED IN THE PAST 1-2 HOURS.  BOUNDARY LAYER

DEWPOINTS RANGE FROM 68-70 F IN ADVANCE OF THE STORMS...WHERE

DEEP-LAYER VERTICAL SHEAR IS SUFFICIENT FOR SUPERCELLS.  THE

ENVIRONMENT SHOULD REMAIN SOMEWHAT FAVORABLE FOR A TORNADO OR TWO

AND ISOLATED DAMAGING WINDS THROUGH ABOUT MID MORNING...WITH A

GRADUALLY DIMINISHING THREAT THEREAFTER AS THE PRIMARY SHORTWAVE

TROUGH PIVOTS BY FARTHER TO THE N.



AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL

SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND

GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450.

MEAN STORM MOTION VECTOR 25040.





...THOMPSON

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