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080 

WWUS20 KWNS 291818

SEL2

SPC WW 291818

ARZ000-LAZ000-TXZ000-300200-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 782

NWS STORM PREDICTION CENTER NORMAN OK

115 PM CDT THU OCT 29 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       SOUTHWEST ARKANSAS

       NORTHWEST LOUISIANA

       SOUTHEAST TEXAS



EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 115 PM UNTIL

900 PM CDT.



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

TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 85 STATUTE

MILES EAST AND WEST OF A LINE FROM 35 MILES EAST NORTHEAST OF

TEXARKANA ARKANSAS TO 60 MILES SOUTHEAST OF HUNTSVILLE TEXAS.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU2).



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.



OTHER WATCH INFORMATION...CONTINUE...WW 781...



DISCUSSION...THUNDERSTORMS ARE GRADUALLY STRENGTHENING IN VERY MOIST

AND MODESTLY UNSTABLE AIR MASS FROM THE TX GULF COAST INLAND ACROSS

THE ARKLATEX. THIS WARM SECTOR DEVELOPMENT IS TAKING PLACE IN AN

ENVIRONMENT CHARACTERIZED BY POTENT LOW LEVEL SHEAR WITH EFFECTIVE

SRH IN EXCESS OF 400 M2/S2. LIFT ACROSS THE REGION SHOULD GRADUALLY

INCREASE AND AID ADDITIONAL STORM DEVELOPMENT INTO THE EVENING AS

STRONG UPPER TROUGH AND COLD FRONT APPROACH FROM THE W/NW. DISCRETE

AND PERSISTENT ROTATING UPDRAFTS WILL HAVE THE GREATEST TORNADO

POTENTIAL...ESPECIALLY THOSE STORMS MOVING INTO AREAS THAT HAVE HAD

MARGINALLY GREATER INSOLATION...AND CELLS CROSSING OR TRACKING NEAR

THE WARM FRONT NOW INTO SRN AR.



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

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

GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.

MEAN STORM MOTION VECTOR 21040.





...CARBIN

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