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967 

WWUS20 KWNS 151627

SEL1

SPC WW 151627

ALZ000-MSZ000-CWZ000-160200-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 141

NWS STORM PREDICTION CENTER NORMAN OK

1120 AM CDT FRI APR 15 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       CENTRAL AND SOUTHERN ALABAMA

       SOUTHEAST MISSISSIPPI

       COASTAL WATERS



EFFECTIVE THIS FRIDAY MORNING AND EVENING FROM 1120 AM UNTIL 900

PM CDT.



TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 65 STATUTE

MILES EAST AND WEST OF A LINE FROM 70 MILES NORTH OF MONTGOMERY

ALABAMA TO 145 MILES SOUTHWEST OF SELMA ALABAMA.  FOR A COMPLETE

DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE

(WOUS64 KWNS WOU1).



REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR

TORNADOES AND 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.



OTHER WATCH INFORMATION...CONTINUE...WW 140...



DISCUSSION...CLUSTER OF SUPERCELLS OVER SERN MS/SWRN AL ARE EXPECTED

TO MOVE/DEVELOP NEWD ACROSS WW AREA WITHIN A DESTABILIZING BOUNDARY

LAYER IN WAKE OF RETREATING WARM FRONT.  HERE...THE COMBINATION OF

DEW POINTS RISING THROUGH THE 60S AND DIABATIC HEATING IN THE

BOUNDARY LAYER WILL YIELD AFTERNOON MLCAPE VALUES INCREASING TO

1000-2000 J/KG.  THIS INSTABILITY COUPLED WITH RATHER STRONG

LOW-LEVEL SHEAR /I.E. EFFECTIVE SRH VALUES OF 200-400 M2 PER S2/

WILL RESULT IN AN ENVIRONMENT QUITE FAVORABLE FOR SUPERCELLS CAPABLE

OF TORNADOES /SOME SIGNIFICANT/...LARGE HAIL APPROACHING 2.0-2.5

INCHES IN DIAMETER AND DAMAGING WIND GUSTS.



AVIATION...TORNADOES AND 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 24030.





...MEAD

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