

000 

WWUS20 KWNS 111857

SEL7

SPC WW 111857

TXZ000-120200-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 57

NWS STORM PREDICTION CENTER NORMAN OK

200 PM CDT SUN MAR 11 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       SOUTHWEST TEXAS



EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 200 PM UNTIL 900

PM CDT.



TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 85 STATUTE

MILES EAST AND WEST OF A LINE FROM 75 MILES WEST NORTHWEST OF SAN

ANGELO TEXAS TO 20 MILES WEST OF DEL RIO TEXAS.  FOR A COMPLETE

DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE

(WOUS64 KWNS WOU7).



REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR

TORNADOES AND 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.



DISCUSSION...GRADUAL CLEARING IS OCCURRING ACROSS SOUTHWEST

TX...ALLOWING AIRMASS TO SLOWLY DESTABILIZE AND CAP TO WEAKEN.

ISOLATED THUNDERSTORMS ARE EXPECTED TO DEVELOP IN THE NEXT COUPLE OF

HOURS OVER THE MOUNTAINS WEST AND SPREAD EASTWARD INTO WATCH AREA.

INCREASING MOISTURE VALUES...COUPLED WITH SUFFICIENT LOW AND DEEP

LAYER VERTICAL SHEAR...WILL PROMOTE SUPERCELLS CAPABLE OF LARGE

HAIL...DAMAGING WINDS...AND ISOLATED TORNADOES.



AVIATION...TORNADOES AND 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

450. MEAN STORM MOTION VECTOR 28030.





...HART

