MESOSCALE DISCUSSION 0500
   NWS STORM PREDICTION CENTER NORMAN OK
   0105 AM CDT THU APR 21 2011
   
   AREAS AFFECTED...NRN AND CNTRL GA
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 173...
   
   VALID 210605Z - 210730Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 173
   CONTINUES.
   
   IT IS NOT CERTAIN THAT A NEW WW WILL BE NEEDED AT 07Z...BUT TRENDS
   DOWNSTREAM...AND UPSTREAM...OF THE REMAINING VALID PORTION OF WW 173
   WILL CONTINUE TO BE MONITORED FOR THE POSSIBILITY OF AN INCREASING
   SEVERE THREAT.
   
   THE MOST PROMINENT THUNDERSTORM ACTIVITY...IN THE FORM OF AN
   ORGANIZED MESOSCALE CONVECTIVE SYSTEM...HAS EXITED THE WATCH...AND
   IS ADVANCING EASTWARD INTO NORTHERN GEORGIA.  EMBEDDED WITHIN A
   25-30 KT WESTERLY MEAN FLOW REGIME...FORWARD PROPAGATION AND
   SOUTHEASTERLY STORM-RELATIVE INFLOW ARE RATHER MODEST.  COUPLED WITH
   WEAK LOW-LEVEL LAPSE RATES...THE ENVIRONMENT APPEARS ONLY MARGINALLY
   SUPPORTIVE OF A CONTINUING SEVERE THREAT...AT BEST.  HOWEVER...STEEP
   MID-LEVEL LAPSE RATES ARE CONTRIBUTING TO SIZABLE CAPE ON THE ORDER
   OF 2000-3000 J/KG...WITH LATEST RUC ANALYSIS SUGGESTING LARGEST CAPE
   OVER CENTRAL/SOUTHERN GEORGIA.  IT SEEMS POSSIBLE THAT THE
   CONVECTIVE SYSTEM COULD GRADUALLY TAKE A MORE EASTWARD TURN ACROSS
   THE ATLANTA METRO AREA AND I-20 CORRIDOR THROUGH NORTH CENTRAL AND
   EASTERN GEORGIA BETWEEN NOW AND 08-10Z.  IF INSTABILITY CONTRIBUTES
   TO INTENSIFYING UPDRAFTS...IT IS NOT OUT OF THE QUESTION THAT THE
   SEVERE THREAT...IN THE FORM OF DAMAGING WIND GUSTS AND LARGE
   HAIL...COULD INCREASE ENOUGH TO REQUIRE A NEW WW.
   
   ..KERR.. 04/21/2011
   
   
   ATTN...WFO...CAE...GSP...FFC...BMX...
   
   LAT...LON   34278528 34398480 34318373 34028295 33678240 33218251
               32868299 32768368 32928460 33088558 33498514 33798497
               34278528