

103 

WWUS20 KWNS 300135

SEL5

SPC WW 300135

LAZ000-TXZ000-CWZ000-300900-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 75

NWS STORM PREDICTION CENTER NORMAN OK

835 PM CDT TUE MAR 29 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHWEST LOUISIANA

       SOUTHEAST TEXAS

       COASTAL WATERS



EFFECTIVE THIS TUESDAY NIGHT AND WEDNESDAY MORNING FROM 835 PM

UNTIL 400 AM 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 65

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 40 MILES NORTHWEST

OF PALACIOS TEXAS TO 20 MILES NORTH NORTHEAST OF LAFAYETTE

LOUISIANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU5).



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 72...WW 73...WW 74...



DISCUSSION...TSTMS SHOULD CONTINUE TO INCREASE ACROSS WW AREA

TONIGHT AS COLD FRONT PROGRESSES SEWD INTO REGION...AND LOW-LATITUDE

SHORT-WAVE TROUGH APPROACHES FROM THE W.  00Z CRP/LCH SOUNDINGS

INDICATED THE PRESENCE OF A MOIST LOW-LEVEL ENVIRONMENT BENEATH AN

EML WITH MUCAPE VALUES OF AROUND 3500 J/KG.  WHEN COUPLED WITH

STEADILY STRENGTHENING SWLY WINDS IN THE MIDLEVELS AND RESULTING

40-50 KT OF EFFECTIVE BULK SHEAR...SETUP WILL FAVOR THE DEVELOPMENT

OF ROBUST STORMS INCLUDING SUPERCELL AND BOWING STRUCTURES WITH THE

PRIMARY HAZARDS BEING LARGE HAIL AND LOCALLY DAMAGING WIND GUSTS.



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 500. MEAN STORM

MOTION VECTOR 25030.





...MEAD

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