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WWUS20 KWNS 261419

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SPC WW 261419

ALZ000-GAZ000-NCZ000-TNZ000-262200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 379

NWS STORM PREDICTION CENTER NORMAN OK

920 AM CDT THU MAY 26 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHERN ALABAMA

       NORTHERN GEORGIA

       WESTERN NORTH CAROLINA

       EASTERN TENNESSEE



EFFECTIVE THIS THURSDAY MORNING AND AFTERNOON FROM 920 AM UNTIL

500 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 65

STATUTE MILES EAST AND WEST OF A LINE FROM 30 MILES WEST

NORTHWEST OF BRISTOL TENNESSEE TO 25 MILES EAST OF TUSCALOOSA

ALABAMA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).



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...PRE-FRONTAL BAND OF TSTMS FROM MIDDLE TN INTO NWRN AL

IS EXPECTED TO INTENSIFY THIS MORNING IN ADVANCE OF MIDLEVEL

VORTICITY OVER THE LOWER MS VALLEY.  12Z REGIONAL SOUNDINGS SHOW A

MOIST AND MODERATELY UNSTABLE INFLOW AIR MASS IN PLACE THIS MORNING

ACROSS CNTRL AL WHERE MLCAPE WAS ALREADY AROUND 2000 J/KG.  AREA

VWPS SHOW A CORRIDOR OF RATHER STRONG LOW-LEVEL SHEAR PRESENTLY

ACROSS ERN TN AND NRN AL.  WHILE A TORNADO IS POSSIBLE...A MORE

ROBUST THREAT MAY BE LIMITED BY THE WEAK LOW-LEVEL LAPSE RATES OWING

TO WIDESPREAD CLOUDS AND BOUNDARY LAYER DEWPOINTS IN THE UPPER 50S

TO LOWER 60S.  OTHERWISE...EXPECT DAMAGING WINDS AND LARGE HAIL TO

BE THE PRIMARY HAZARDS WITH EMBEDDED BOWING AND SUPERCELL

STRUCTURES.



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 24035.





...MEAD

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