MESOSCALE DISCUSSION 0534
   NWS STORM PREDICTION CENTER NORMAN OK
   1257 PM CDT FRI APR 19 2013
   
   AREAS AFFECTED...PORTIONS ERN/SRN SC...CENTRAL-ERN GA...NRN FL AND
   CENTRAL/ERN FL PANHANDLE.
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 129...
   
   VALID 191757Z - 192000Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 129
   CONTINUES.
   
   SUMMARY...WW MAY BE CLEARED BEHIND PRIMARY/FRONTAL CONVECTIVE BAND. 
   SOME COUNTIES IN CENTRAL SC WILL BE ADDED TO THIS WW PER COORD W/WFO
   CAE.  NEW WW MAY BE REQUIRED EWD BETWEEN WW 129 AND ATLC COAST FOR
   PARTS OF SERN GA...SRN SC AND/OR NRN FL.
   
   PRIMARY CONVECTIVE BAND FCST TO CONTINUE POSING SVR THREAT AS IT
   MOVES EWD ACROSS WW AREA -- MAINLY WIND BUT WITH A QLCS/BOW-ECHO
   TORNADO OR TWO POSSIBLE.  CONVECTION DEVELOPING AHEAD OF LINE...IN
   ERN PORTIONS WW...ALSO MAY OFFER POTENTIAL FOR SVR AS IT MOVES NEWD.
   
   DISCUSSION...PREFRONTAL AIR MASS CONTINUES TO DESTABILIZE WITH SFC
   DIABATIC HEATING ACROSS GA/SC/NRN FL.  DEW POINTS UPPER 60S TO LOW
   70S F MAY DECLINE IN SPOTS DUE TO VERTICAL MIXING...BUT GENERALLY
   WILL BE MAINTAINED ACROSS THIS REGION.  HEATING AND RICH SFC THETAE
   WILL OFFSET WEAK LAPSE RATES ALOFT IN REINFORCING BUOYANCY AND
   REMOVING ALREADY WEAK MLCINH.  MLCAPE COMMONLY IN 1000-1500 J/KG
   RANGE IS EXPECTED BY 20Z...WHILE EFFECTIVE SHEAR MAGNITUDES OF 35-45
   KT SHOULD BE COMMON IMMEDIATELY AHEAD OF SFC COLD FRONT.  DEEP SHEAR
   WILL WEAKEN WITH EWD EXTENT TOWARD COAST...BUT ALSO INCREASE WITH
   TIME IN ANY GIVEN SPOT.  PRIMARY QLCS STRUCTURE WILL BE MAINTAINED
   WITH LINEAR/FRONTAL FORCING AND FLOW ALOFT SUBSTANTIALLY PARALLEL TO
   BOUNDARY.  HOWEVER...MORE DISCRETE WARM-SECTOR CONVECTION AHEAD OF
   THAT MAY ASSUME TRANSIENT SUPERCELLULAR CHARACTERISTICS AMIDST AT
   LEAST MARGINALLY FAVORABLE HODOGRAPHS -- E.G. EFFECTIVE SRH 100-200
   J/KG.
   
   ..EDWARDS/MEAD.. 04/19/2013
   
   
   ATTN...WFO...ILM...CHS...CAE...GSP...TBW...JAX...FFC...TAE...
   
   LAT...LON   29988547 31998414 33898323 34018149 33748019 33637975
               33487925 33387912 33147918 32558013 32048084 31388125
               30708141 30128134 29398209 29328313 29498338 29668338
               29768359 29928367 30108402 29608490 29988547