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WWUS20 KWNS 171643

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SPC WW 171643

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URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 490

NWS STORM PREDICTION CENTER NORMAN OK

1145 AM CDT FRI JUN 17 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       PARTS OF CENTRAL AND SOUTHERN ALABAMA

       PARTS OF SOUTHEASTERN MISSISSIPPI



EFFECTIVE THIS FRIDAY MORNING AND EVENING FROM 1145 AM UNTIL 600

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 NORTH AND SOUTH OF A LINE FROM 30 MILES NORTHWEST

OF PINE BELT MISSISSIPPI TO 20 MILES EAST NORTHEAST OF AUBURN

ALABAMA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).



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...COOL POOL CONTINUES PUSHING SWD INTO CENTRAL AL WWD

INTO MS WHILE CONVECTION IS NOW DEVELOPING ALONG NWD MOVING SEA

BREEZE FRONT GULF COAST AREA.  WITH AIR MASS BETWEEN NOW QUITE

UNSTABLE...I.E. MLCAPES IN EXCESS OF 3000 J/KG AND 20-25 KT OF

SHEAR...POTENTIAL EXPECTED TO INCREASE FOR SEVERE THUNDERSTORMS

ACROSS THE WATCH THRU THE AFTERNOON.  PRIMARY THREAT WILL BE

DAMAGING DOWNBURST WINDS AND LARGE HAIL.



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 30015.





...HALES

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