

945 

WWUS20 KWNS 161301

SEL1

SPC WW 161301

TXZ000-CWZ000-162000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 181

NWS STORM PREDICTION CENTER NORMAN OK

800 AM CDT MON APR 16 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       MIDDLE AND LOWER TEXAS COAST

       COASTAL WATERS



EFFECTIVE THIS MONDAY MORNING AND AFTERNOON FROM 800 AM UNTIL 300

PM CDT.



HAIL TO 2 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 55

STATUTE MILES EAST AND WEST OF A LINE FROM 30 MILES EAST OF

BEEVILLE TEXAS TO 25 MILES SOUTHEAST OF MCALLEN 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...BACK-BUILDING STORMS ALONG A SLOW-MOVING FRONT ARE

EXPECTED TO EXPAND SWD DURING THE DAY INTO AN ENVIRONMENT WITH

WEAKENING CONVECTIVE INHIBITION AND STRONG INSTABILITY.  DEEP-LAYER

VERTICAL SHEAR WILL BE MARGINALLY FAVORABLE FOR ORGANIZED

MULTICELLS/SUPERCELLS...WITH A RISK FOR LARGE HAIL/DAMAGING WINDS.

ALSO...AN ISOLATED TORNADO CANNOT BE RULED OUT WITH STORMS

INTERACTING WITH THE BOUNDARY...WHERE LOW-LEVEL SHEAR WILL BE

SLIGHTLY ENHANCED.



AVIATION...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 550. MEAN STORM

MOTION VECTOR 27010.





...THOMPSON

