

223 

WWUS20 KWNS 111952

SEL8

SPC WW 111952

LAZ000-MSZ000-TXZ000-CWZ000-120100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 288

NWS STORM PREDICTION CENTER NORMAN OK

250 PM CDT MON MAY 11 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       PARTS OF CENTRAL AND SOUTHERN LOUISIANA

       SMALL PART OF SOUTHWEST MISSISSIPPI

       PARTS OF SOUTHEAST TEXAS

       COASTAL WATERS



EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 250 PM UNTIL 800

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 NORTH AND SOUTH OF A LINE FROM 40 MILES NORTHEAST

OF BATON ROUGE LOUISIANA TO 25 MILES NORTH NORTHWEST OF ANGLETON

TEXAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU8).



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...THUNDERSTORMS INCREASING IN NUMBER AND INTENSITY ACROSS

WATCH AREA AS SURFACE BOUNDARIES MOVE SEWD THRU A MDTLY UNSTABLE AIR

MASS.  ALTHOUGH SHEAR IS MARGINAL...INSTABILITY SUPPORTS DAMAGING

WINDS WITH HAIL IN STRONGER UPDRAFTS AS THEY MOVE SLOWLY E/SE ACROSS

THE WATCH.



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 27020.





...HALES

