MESOSCALE DISCUSSION 1983
   NWS STORM PREDICTION CENTER NORMAN OK
   1252 PM CDT SUN AUG 30 2009
   
   AREAS AFFECTED...PORTIONS CENTRAL/SRN AL...GA...SC...FL
   PANHANDLE...EXTREME SERN MS.
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 301752Z - 301945Z
   
   TSTMS ARE FCST TO INCREASE IN COVERAGE AND INTENSITY THROUGH AT
   LEAST MID-AFTERNOON ACROSS DISCUSSION AREA...WITH MAIN CONCERNS
   BEING STG-SVR GUSTS AND HEAVY RAINFALL OF 2-3 INCHES/HOUR WITH MOST
   INTENSE CELLS.
   
   PRIMARY CONCENTRATIONS OF CONVECTION ARE FCST TO REMAIN IN BANDS OF
   ENHANCED DEEP-LAYER ASCENT...AHEAD OF SHORTWAVE TROUGH THAT NOW IS
   EVIDENT OVER PORTIONS MS.  TROUGH IS FCST TO LIFT ENEWD THROUGH
   REMAINDER AFTERNOON...WHILE BANDS OF LIFT -- INITIALLY OVER SERN MS
   AND S-CENTRAL AL -- LIKEWISE MOVE ENEWD ACROSS PORTIONS AL/GA. 
   ADDITIONAL TSTMS ARE DEVELOPING WITHIN BROAD/DIFFUSE BAROCLINIC ZONE
   RELATED TO DIFFERENTIAL HEATING FROM SERN AL NEWD ACROSS
   W-CENTRAL-NERN GA.  COVERAGE WILL REMAIN MORE ISOLATED TO WIDELY
   SCATTERED EWD AND SWD TOWARD ATLANTIC/GULF SEA BREEZES AND AHEAD OF
   UVV BANDS INITIALLY OVER MS/AL.  PRECONVECTIVE AIR MASS CONTINUES TO
   DESTABILIZE FAVORABLY...WITH STG SFC HEATING AND MOISTURE RICH
   BOUNDARY LAYER -- E.G. DEW POINTS LOW-MID 70S F -- CONTRIBUTING TO
   MLCAPE 2000-3000 J/KG BY 20Z.  LOW LEVEL FLOW WILL REMAIN
   WEAK...LIMITING HODOGRAPH SIZE AND SRH.  HOWEVER...ENHANCED
   MID-UPPER LEVEL GRADIENT FLOW AHEAD OF TROUGH ALOFT WILL CONTRIBUTE
   TO EFFECTIVE SHEAR 35-40 KT OVER BROAD SWATH FROM COASTAL MS/AL TO
   CAROLINAS...IN SUPPORT OF ORGANIZATION WITHIN PREDOMINANT
   MULTICELLULAR STORM MODE.  MRGL SUPERCELL STRUCTURES ALSO ARE
   POSSIBLE...BUT GIVEN WEAKNESS OF AMBIENT SHEAR...SUCH MORPHOLOGY
   LIKELY WILL REQUIRE LOCALIZED...LOW-LEVEL VORTICITY SUPPLEMENTATION
   BY FAVORABLY ORIENTED SEA BREEZE OR OUTFLOW BOUNDARIES WITH WHICH
   STORMS CAN INTERACT MORE THAN BRIEFLY.
   
   ..EDWARDS.. 08/30/2009
   
   
   ATTN...WFO...CHS...CAE...GSP...JAX...FFC...TAE...BMX...MOB...
   LIX...
   
   LAT...LON   32728034 30928284 30448382 30118464 30108504 30598608
               30388780 30508936 32278778 32328686 33098506 34508260
               34298017 32728034