

556 

WWUS20 KWNS 261552

SEL5

SPC WW 261552

LAZ000-TXZ000-CWZ000-262300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 735

NWS STORM PREDICTION CENTER NORMAN OK

1050 AM CDT WED AUG 26 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHWEST LOUISIANA

       SOUTHEAST TEXAS

       COASTAL WATERS



EFFECTIVE THIS WEDNESDAY MORNING AND EVENING FROM 1050 AM UNTIL

600 PM CDT.



HAIL TO 1.5 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 EITHER SIDE OF A LINE FROM 30 MILES NORTH OF LAKE

CHARLES LOUISIANA TO 65 MILES WEST NORTHWEST OF ANGLETON TEXAS.

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.



DISCUSSION...TSTMS DEVELOPING WITHIN MOIST AND MODERATELY UNSTABLE

AIR MASS /MLCAPE APPROACHING 1500-2500 J PER KG/ ARE EXPECTED TO

INCREASE IN COVERAGE AND INTENSITY TODAY WITH ACTIVITY

MOVING/PROPAGATING SWD/SWWD TOWARD THE GULF COAST.  THE PRESENCE OF

MODERATELY STRONG MID AND HIGH-LEVEL FLOW ON WRN PERIPHERY OF LOWER

MS VALLEY VORTICITY MAXIMUM WILL SUPPORT THE EVOLUTION OF

FORWARD-PROPAGATING STORM CLUSTERS AND PERHAPS SOME MARGINAL

SUPERCELLS WITH THE THREAT FOR DAMAGING WIND GUSTS AND SOME HAIL.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM

MOTION VECTOR 02030.





...MEAD/WEISS

