

488 

WWUS20 KWNS 291736

SEL3

SPC WW 291736

LAZ000-MSZ000-CWZ000-300100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 233

NWS STORM PREDICTION CENTER NORMAN OK

1235 PM CDT SAT MAY 29 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       LARGE PART OF SOUTHEASTERN LOUISIANA

       MUCH OF SOUTHERN MISSISSIPPI

       COASTAL WATERS



EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 1235 PM UNTIL

800 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 105

STATUTE MILES EAST AND WEST OF A LINE FROM 50 MILES NORTH

NORTHEAST OF MC COMB MISSISSIPPI TO 40 MILES SOUTHEAST OF HOUMA

LOUISIANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU3).



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 232...



DISCUSSION...AIR MASS TO W AND S OF UPPER LOW NEAR KJAN HAS BECOME

MDTLY UNSTABLE WITH MLCAPES AOA 2500 J/KG.  WITH A CYCLONIC FLOW OF

RELATIVELY COOL/STEEP MID LEVEL LAPSE RATES ASSOCIATED WITH UPPER

LOW...STORMS WILL INCREASE RAPIDLY IN NUMBER AND INTENSITY AS THEY

MOVE/PROPAGATE SEWD ACROSS THE WATCH.  MULTICELLULAR/PULSE MODE IN

RELATIVELY WEAK SHEAR REGIME SHOULD SUPPORT BOTH LARGE HAIL AND

DAMAGING DOWNBURSTS WINDS WITH STRONGEST STORMS.



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 31015.





...HALES

