Today's Featured Post: Updated Long Range Outlook Will be Issued Wednesday at 4:30 PM Central Time.

Wednesday, April 20, 2011

April 20: Severe Thunderstorm Watch #2


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.

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