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WWUS20 KWNS 202116

SEL1

SPC WW 202116

LAZ000-MSZ000-TXZ000-210400-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 1

NWS STORM PREDICTION CENTER NORMAN OK

315 PM CST WED JAN 20 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       PARTS OF LOUISIANA

       SOUTHWEST MISSISSIPPI

       SOUTHEAST TEXAS



EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 315 PM UNTIL

1000 PM CST.



TORNADOES...HAIL TO 1.5 INCHES 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 NORTH AND SOUTH OF A LINE FROM 80 MILES WEST OF FORT POLK

LOUISIANA TO 60 MILES EAST OF MC COMB MISSISSIPPI.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU1).



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...TSTMS SHOULD CONTINUE TO INCREASE IN COVERAGE AND

INTENSITY THIS AFTERNOON INTO EVENING...DRIVEN BY BROAD LOW-LEVEL

WAA REGIME.  AMBIENT AIR MASS HAS BECOME WARM...MOIST AND MODERATELY

UNSTABLE WITH MLCAPE OF 1000-2000 J/KG.  WHEN COUPLED WITH 40-45 KT

OF DEEP-LAYER LAYER AND STEADILY STRENGTHENING LOW-LEVEL SHEAR ALONG

LLJ AXIS...ENVIRONMENT WILL FAVOR THE DEVELOPMENT OF SUPERCELLS

CAPABLE OF A FEW TORNADOES...IN ADDITION TO HAIL AND LOCALLY

DAMAGING WIND GUSTS.



AVIATION...TORNADOES AND 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

450. MEAN STORM MOTION VECTOR 24035.





...MEAD/WEISS

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