

135 

WWUS20 KWNS 180418

SEL0

SPC WW 180418

TXZ000-180900-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 600

NWS STORM PREDICTION CENTER NORMAN OK

1120 PM CDT FRI JUL 17 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHWEST TEXAS



EFFECTIVE THIS FRIDAY NIGHT AND SATURDAY MORNING FROM 1120 PM

UNTIL 400 AM 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 60

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

MARFA TEXAS TO 80 MILES SOUTHEAST OF MIDLAND TEXAS.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU0).



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.



OTHER WATCH INFORMATION...CONTINUE...WW 599...



DISCUSSION...NEW THUNDERSTORMS HAVE RAPIDLY DEVELOPED ALONG OUTFLOW

BOUNDARY MOVING SWD INTO THE PERMIAN BASIN.  THIS IS EXPECTED TO

REINFORCE COLD POOL PRODUCTION BEHIND THE GUST FRONT...WHICH IS

EXPECTED TO PROGRESS SWD INTO THE EARLY MORNING HOURS WITH A

CONTINUED THREAT FOR DAMAGING WND GUSTS.



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 500. MEAN STORM

MOTION VECTOR 32025.





...WEISS

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