

000 

WWUS20 KWNS 212019

SEL4

SPC WW 212019

TXZ000-220400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 284

NWS STORM PREDICTION CENTER NORMAN OK

320 PM CDT MON MAY 21 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHWEST TEXAS AND THE TEXAS BIG BEND



EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 320 PM UNTIL

1100 PM CDT.



HAIL TO 3 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 100

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

FORT STOCKTON TEXAS TO 55 MILES SOUTH SOUTHEAST OF DRYDEN TEXAS.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU4).



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 282...WW 283...



DISCUSSION...TSTMS NOW FORMING OVER THE HIGHER TERRAIN OF SW TX

EXPECTED TO STRENGTHEN AND MOVE/DEVELOP GENERALLY ESE INTO

INCREASINGLY RICH SSELY MOISTURE RETURN UP THE RIO GRANDE.  MODERATE

WLY FLOW ASSOCIATED WITH NRN FRINGE OF SRN STREAM JET SHOULD SUPPORT

DEVELOPMENT OF A FEW SUSTAINED STORMS/SUPERCELLS WITH VERY LARGE

HAIL/HIGH WIND AND POSSIBLY A BRIEF TORNADO.  ACTIVITY MAY MERGE

INTO A CLUSTER BY EARLY EVENING...WITH A CONTINUING THREAT FOR SVR

E/SE ALONG AND N OF THE RIO GRANDE.



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

TO 3 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM

MOTION VECTOR 30020.





...CORFIDI

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