

897 

WWUS20 KWNS 071746

SEL1

SPC WW 071746

TXZ000-080200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 261

NWS STORM PREDICTION CENTER NORMAN OK

1245 PM CDT MON MAY 7 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHWEST AND WEST-CENTRAL TEXAS



EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 1245 PM UNTIL

900 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 85

STATUTE MILES EAST AND WEST OF A LINE FROM 20 MILES SOUTHEAST OF

DRYDEN TEXAS TO 65 MILES NORTHWEST OF BROWNWOOD 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...TSTMS ARE RAPIDLY DEVELOPING THIS AFTERNOON AHEAD OF

COLD FRONT AND LIKELY IN ASSOCIATION WITH A WEAK MIDLEVEL IMPULSE

MOVING THROUGH THE TX BIG BEND.  WARM SECTOR AIR MASS IS ALREADY

MODERATE-STRONGLY UNSTABLE OWING TO THE PRESENCE OF STEEP LAPSE

RATES AND A MOIST BOUNDARY LAYER.  WHEN COUPLED WITH 35-45 KT OF

DEEP SWLY SHEAR...SETUP WILL FAVOR THE DEVELOPMENT OF SUPERCELLS

CAPABLE OF VERY LARGE HAIL AND DAMAGING WIND GUSTS AS THE PRIMARY

HAZARDS.



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 27020.





...MEAD

