MESOSCALE DISCUSSION 1075
   NWS STORM PREDICTION CENTER NORMAN OK
   0108 PM CDT FRI JUN 12 2009
   
   AREAS AFFECTED...PARTS OF THE CAROLINA-GA PIEDMONT / SC COASTAL
   PLAIN
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 121808Z - 121915Z
   
   THE AREA INCLUDING PARTS OF THE CAROLINA/GA PIEDMONT EXTENDING EWD
   TO THE SC COASTAL PLAIN IS BEING MONITORED FOR A WW.  MAIN THREATS
   WILL BE MARGINALLY SEVERE HAIL/ISOLD DMGG WINDS.
   
   VISIBLE SATELLITE IMAGERY IS TRACKING A REMNANT MCV OVER THE NC
   COASTAL PLAIN WITH AN AREA DEVOID OF A CU FIELD IMMEDIATELY IN ITS
   WAKE--INDICATIVE OF IMPLIED SUBSIDENCE.  FARTHER W...A CLUSTER OF
   AGITATED CU HAS FORMED OVER THE HIGHER TERRAIN OF THE SRN
   APPALACHIANS/ADJACENT UPSTATE AREAS.  18Z SUBJECTIVE SURFACE
   ANALYSIS SHOWS A LEE TROUGH/WINDSHIFT FROM NEAR RDU TO CAE TO NEAR
   AGS.  WEAK CONVERGENCE ASSOCIATED WITH THIS FEATURE ALONG WITH
   STRONG HEATING ALONG THE E-SLOPES OF THE HIGHER TERRAIN MAY SERVE AS
   PREFERRED AREAS FOR TSTM DEVELOPMENT.  
   
   STRONG DIABATIC HEATING OVER THE AREA WILL CONTINUE TO DEPLETE
   REMAINING CINH WITH ALREADY WEAKENED CAP.  THIS NOTION IS SUPPORTED
   BY MODIFYING 12Z CHS/FFC RAOBS FOR UPPER 80S TEMPS/DEWPOINTS NEAR 70
   F...SUGGESTING THE CAP HAS BEEN SUFFICIENTLY WEAKENED AND RESULTING
   IN A POTENTIALLY VERY UNSTABLE AIRMASS /2500-3500 J/KG MLCAPE/ OVER
   SC/GA.  DESPITE NEUTRAL TO WEAK RIDING ALOFT...MAGNITUDE OF
   POTENTIAL INSTABILITY WILL LIKELY AID IN TSTM GROWTH/SUSTENANCE WITH
   TIME.  THE MOST ORGANIZED SEVERE THREAT MAY EVOLVE ACROSS THE SC
   UPSTATE NWD INTO THE NC PIEDMONT WHERE MARGINAL DEEP LAYER SHEAR
   /ALBEIT WEAKER INSTABILITY/ MAY HELP ORGANIZE CONVECTION.  SCATTERED
   TSTM COVERAGE MAY THEN LEAD TO AN EWD MOVING CLUSTER/SMALL BOWING
   SEGMENTS WITH A PREDOMINATE ISOLD WIND THREAT EVOLVING WITH TIME.
   
   ..SMITH.. 06/12/2009
   
   
   ATTN...WFO...RAH...ILM...RNK...CHS...CAE...GSP...FFC...
   
   LAT...LON   35997908 35607942 35088039 34638062 34378040 34227971
               34137883 33837862 33227949 33088055 33088128 33368220
               33628285 33988323 34678305 34978282 35398248 35878167
               36388039 36497962 36297911 35997908