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WWUS20 KWNS 171838

SEL1

SPC WW 171838

TXZ000-180100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 151

NWS STORM PREDICTION CENTER NORMAN OK

140 PM CDT TUE APR 17 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       WESTERN NORTH TEXAS



EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 140 PM UNTIL

800 PM CDT.



HAIL TO 2 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 80

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 115 MILES WEST

NORTHWEST OF ABILENE TEXAS TO 15 MILES EAST NORTHEAST OF

STEPHENVILLE 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...SCATTERED THUNDERSTORMS ARE INCREASING OVER WEST TX IN

REGION OF STRONG DAYTIME HEATING AND STEEP LOW LEVEL LAPSE RATES.

CLEARING SKIES ARE EXPECTED TO DEVELOP EASTWARD ACROSS WATCH AREA

THIS AFTERNOON...WITH STORMS ALSO SPREADING ACROSS REGION.  LARGE

HAIL IS LIKELY DUE TO COLD MID LEVEL TEMPERATURES.  POTENTIAL ALSO

EXISTS FOR ISOLATED LANDSPOUTS GIVEN FAVORABLE THERMODYNAMIC AND

AMBIENT VORTICITY PATTERN.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM

MOTION VECTOR 27030.





...HART

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