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WWUS20 KWNS 301935

SEL9

SPC WW 301935

TXZ000-010300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 209

NWS STORM PREDICTION CENTER NORMAN OK

235 PM CDT MON APR 30 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHWEST TEXAS



EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 235 PM UNTIL

1000 PM CDT.



HAIL TO 2.5 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 EAST AND WEST OF A LINE FROM 95 MILES SOUTH

SOUTHEAST OF MARFA TEXAS TO 20 MILES WEST NORTHWEST OF MIDLAND

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

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).



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 208...



DISCUSSION...INCIPIENT TSTM DEVELOPMENT IS UNDERWAY ALONG THE DAVIS

MOUNTAINS W OF FST.  INFLOW AIR MASS IS CHARACTERIZED BY A

HOT...MOIST BOUNDARY LAYER WITH MLCAPE OF 2000-3000 J/KG.  THIS

INSTABILITY COMBINED WITH A VERTICALLY VEERING WIND PROFILE AND

30-35 KT OF DEEP-LAYER SHEAR WILL SUPPORT SUPERCELL STORM MODES WITH

THE PRIMARY HAZARD BEING LARGE HAIL.



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

TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

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

MOTION VECTOR 27015.





...MEAD

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