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WWUS20 KWNS 201835

SEL9

SPC WW 201835

ALZ000-GAZ000-210200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 169

NWS STORM PREDICTION CENTER NORMAN OK

235 PM EDT WED APR 20 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       ALABAMA

       SOUTHWEST GEORGIA



EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 235 PM UNTIL

1000 PM EDT.



HAIL TO 1.5 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 70

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

COLUMBUS MISSISSIPPI TO 35 MILES EAST NORTHEAST OF ALBANY

GEORGIA.  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.



OTHER WATCH INFORMATION...CONTINUE...WW 168...



DISCUSSION...TSTMS WILL CONTINUE TO INCREASE IN COVERAGE AND

INTENSITY THIS AFTERNOON ALONG OUTFLOW BOUNDARY EXTENDING ALONG A

LINE FROM MEI-MGM-E OF CSG...AND WITHIN A MODERATELY TO STRONGLY

UNSTABLE AIR MASS WITH MLCAPE VALUES OF 2000-3000 J/KG.

ADDITIONAL...ELEVATED TSTMS WILL ALSO LIKELY MOVE INTO PARTS OF NWRN

AL...ROOTED WITHIN STEEP MIDLEVEL LAPSE RATE ENVIRONMENT.

TROPOSPHERIC WIND FIELD IS FORECAST TO WEAKEN THROUGH THE AFTERNOON

WITH PROGRESSION OF UPPER TROUGH AXIS AWAY FROM THE AREA.

NONETHELESS...SUFFICIENT VERTICAL SHEAR WILL EXIST FOR MULTICELL

STORMS CAPABLE OF LARGE HAIL AND DAMAGING WINDS.



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

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

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

MOTION VECTOR 27030.





...MEAD

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