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URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 727

NWS STORM PREDICTION CENTER NORMAN OK

345 PM CDT THU AUG 4 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       EXTREME WESTERN ALABAMA

       NORTHEAST AND CENTRAL MISSISSIPPI



EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 345 PM UNTIL

1100 PM CDT.



HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS TO 75

MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 50

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 45 MILES EAST

NORTHEAST OF COLUMBUS MISSISSIPPI TO 25 MILES SOUTH OF GREENWOOD

MISSISSIPPI.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU7).



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 HAVE INCREASED ALONG THE COLLISION OF OUTFLOW

BOUNDARIES OVER NWRN AL AND NERN MS LATE THIS AFTN.  STORMS ARE

DEVELOPING IN A VERY UNSTABLE AIR MASS WHERE SFC TEMPERATURES ARE IN

EXCESS OF 95-100F IN THE MIDST OF MID-UPR 70S BOUNDARY LAYER DEW

POINTS.  DEEP NLY FLOW THROUGH THE COLUMN AND STRENGTHENING COLD

POOL WILL CONTRIBUTE TO CORRIDORS OF DMGG WIND GUSTS AND MRGLLY SVR

HAIL.  STORMS WILL PROPAGATE SWD AND SWWD INTO THE HOT BOUNDARY

LAYER ALONG TRAILING COLD POOL INTO CNTRL MS THROUGH EARLY EVENING.



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

TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 65 KNOTS.

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

VECTOR 35030.





...RACY

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