MESOSCALE DISCUSSION 0449
   NWS STORM PREDICTION CENTER NORMAN OK
   0143 AM CDT SAT APR 16 2011
   
   AREAS AFFECTED...SERN AL INTO SRN GA...AND ADJACENT PORTIONS OF THE
   FL PANHANDLE/NRN FL
   
   CONCERNING...TORNADO WATCH 146...
   
   VALID 160643Z - 160815Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 146 CONTINUES.
   
   A NEW WW WILL LIKELY BE NEEDED PRIOR TO 08Z EXPIRATION OF WW 146.
   
   WITH ANOTHER SIGNIFICANT SHORT WAVE IMPULSE STILL IN THE PROCESS OF
   PIVOTING AROUND THE SOUTHERN PERIPHERY OF THE LARGE CLOSED LOW OVER
   THE MIDDLE MISSISSIPPI VALLEY...A SURFACE COLD FRONT...AND A
   CONFLUENCE ZONE JUST AHEAD OF IT...WILL ONLY SLOWLY ADVANCE EASTWARD
   THROUGH NORTHWEST GEORGIA/EASTERN ALABAMA AND THE WESTERN FLORIDA
   PANHANDLE TONIGHT.  IN ADVANCE OF THE PRE-FRONTAL CONFLUENCE
   ZONE...A NARROW TONGUE OF BETTER MOISTURE RETURN OFF THE GULF OF
   MEXICO /CHARACTERIZED BY MID 60S SURFACE DEW POINTS/ CONTINUES TO
   SUPPORT WEAK TO MODERATE BOUNDARY LAYER INSTABILITY...WITH CAPE ON
   THE ORDER OF 500-1000 J/KG AS FAR NORTH AS SOUTHEASTERN ALABAMA AND
   SOUTHWESTERN GEORGIA.  COUPLED WITH FAVORABLE LARGE-SCALE
   ASCENT...THIS SEEMS LIKELY TO MAINTAIN DISCRETE ONGOING CONVECTIVE
   DEVELOPMENT NOW APPROACHING THE DOTHAN AL AREA...WHICH PROBABLY WILL
   SPREAD INTO SOUTHWEST GEORGIA ...NEAR AND SOUTHWEST OF
   ALBANY...THROUGH 08-10Z.  ALTHOUGH STRONGER LOW-LEVEL FLOW FIELDS
   MAY CONTINUE TO SHIFT NORTHEAST OF THE REGION...TO THE LEE OF THE
   SOUTHERN APPALACHIANS THROUGH THE REMAINDER OF THE
   NIGHT...HODOGRAPHS CLOSER TO COASTAL AREAS STILL SHOULD REMAIN
   FAVORABLE FOR SUPERCELLS CAPABLE OF PRODUCING TORNADOES.
   
   ..KERR.. 04/16/2011
   
   
   ATTN...WFO...TAE...BMX...
   
   LAT...LON   31548591 31758527 31788471 31708418 31368396 30938423
               30828482 30868537 30908584 31218613 31548591