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WWUS20 KWNS 051913

SEL1

SPC WW 051913

NMZ000-TXZ000-060200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 911

NWS STORM PREDICTION CENTER NORMAN OK

210 PM CDT SUN OCT 5 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHEAST NEW MEXICO

       WEST TEXAS



EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 210 PM UNTIL 900

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 75

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 50 MILES NORTH

NORTHWEST OF MARFA TEXAS TO 75 MILES NORTHEAST OF BIG SPRING

TEXAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).



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.



DISCUSSION...A PRONOUNCED MID LEVEL TROUGH IS MOVING EWD INTO FAR W

TX AND SE NM AS OF EARLY AFTERNOON.  THUNDERSTORMS ARE EXPECTED TO

INCREASE IN COVERAGE AND INTENSITY BY MID-LATE AFTERNOON ACROSS W

CENTRAL TX AND SE NM IN ADVANCE OF THE TROUGH...WHERE SURFACE

HEATING IN CLOUD BREAKS AND DEWPOINTS OF 56-60 F ARE CONTRIBUTING TO

MLCAPE VALUES NEAR 1000 J/KG.  VERTICAL SHEAR WILL BE SUFFICIENT FOR

A FEW SUPERCELLS WHICH WILL LOCALLY ENHANCE THE HAIL THREAT...WHILE

CONVECTION SHOULD EVENTUALLY GROW UPSCALE INTO AN EXTENSIVE N-S BAND

BY THIS EVENING WITH THE POTENTIAL TO PRODUCE AT LEAST ISOLATED

DAMAGING WINDS.  ANY TORNADO THREAT SHOULD REMAIN BRIEF/ISOLATED

GIVEN ONLY MODEST INSTABILITY AND LOW-LEVEL SHEAR.



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 450. MEAN STORM

MOTION VECTOR 24030.





...THOMPSON

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