628
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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