

000 

WWUS20 KWNS 302004

SEL3

SPC WW 302004

TXZ000-010300-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 203

NWS STORM PREDICTION CENTER NORMAN OK

300 PM CDT MON APR 30 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       SOUTH CENTRAL TEXAS



EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 300 PM UNTIL

1000 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 55 STATUTE

MILES EAST AND WEST OF A LINE FROM 55 MILES EAST SOUTHEAST OF

LAREDO TEXAS TO 60 MILES NORTHWEST OF COTULLA TEXAS.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU3).



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.



OTHER WATCH INFORMATION...CONTINUE...WW 202...



DISCUSSION...TSTMS ARE EXPECTED TO BECOME INCREASINGLY NUMEROUS THIS

AFTERNOON INTO EVENING ALONG AND S OF OUTFLOW BOUNDARY STALLING

ACROSS THE AREA.  OTHER STORMS DEVELOPING ALONG THE HIGHER TERRAIN

OF NERN MEXICO MAY ALSO CROSS THE INTERNATIONAL BORDER BY LATE

AFTERNOON OR EVENING. COMBINATION OF MLCAPES OF 2000-3000 J/KG AND

40-45 KT OF EFFECTIVE BULK SHEAR INDICATE THE POTENTIAL FOR

SUPERCELLS CAPABLE OF LARGE HAIL.  ISOLATED TORNADOES WILL ALSO BE

POSSIBLE...ESPECIALLY WITH ANY MATURE STORMS THAT FAVORABLY INTERACT

WITH OUTFLOW BOUNDARY WHERE LOW-LEVEL SHEAR WILL BE ENHANCED.



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

500. MEAN STORM MOTION VECTOR 29020.





...MEAD/THOMPSON

