ZCZC SPCSWOMCD ALL ACUS11 KWNS 251546 SPC MCD 251546 SCZ000-GAZ000-NCZ000-TNZ000-ALZ000-251815- MESOSCALE DISCUSSION 0692 NWS STORM PREDICTION CENTER NORMAN OK 1046 AM CDT SUN MAY 25 2014 AREAS AFFECTED...PORTIONS OF MIDDLE/ERN TN...WRN NC...SRN/WRN SC...NRN/ERN GA CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 251546Z - 251815Z PROBABILITY OF WATCH ISSUANCE...20 PERCENT SUMMARY...THE RISK FOR ISOLATED SEVERE THUNDERSTORMS WILL DEVELOP INTO THE AFTERNOON HOURS. WHILE CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED THROUGH THE DAY...THE ISSUANCE OF A WW IS CURRENTLY UNLIKELY. DISCUSSION...VIS SATELLITE AND MOSAIC RADAR IMAGERY INDICATE CONVECTION DEEPENING WITHIN A QUASI-STATIONARY FRONTAL ZONE ANALYZED FROM MIDDLE TN TO THE PIEDMONT AND COASTAL PLAIN OF CNTRL SC AND OFF THE COAST. LIGHTING DATA SUGGEST INCREASING THUNDERSTORM COVERAGE OVER PARTS OF MIDDLE/ERN TN. THE AIR MASS S OF THE BOUNDARY CONTINUES TO DIURNALLY DESTABILIZE -- E.G. MLCAPE CURRENTLY AROUND 500-1500 J/KG PER MODIFIED 12Z BNA/FFC/CHS RAOBS. THUNDERSTORMS SHOULD INCREASE IN NUMBER AND INTENSITY AS ADDITIONAL SFC HEATING CONTRIBUTES TO STEEPENING OF LOW-LEVEL LAPSE RATES BENEATH ONLY MODESTLY STEEP MID-LEVEL LAPSE RATES. TERRAIN-DRIVEN CIRCULATIONS OVER THE SRN APPALACHIANS AND STRENGTHENING SEA BREEZE BOUNDARIES WILL ALSO ENCOURAGE CONVECTIVE DEVELOPMENT THROUGH THE DAY. ISOLATED DMGG WIND GUSTS AND PERHAPS MARGINALLY SVR HAIL WILL BE POSSIBLE THROUGH THE AFTERNOON OWING TO MODERATE BUOYANCY AND SUFFICIENT HIGH-LEVEL VENTILATION. A FEW PERSISTENT MULTICELL CLUSTERS MAY EVOLVE PROVIDED 25-30 KT OF MID-LEVEL NWLY/S AIDING FORWARD PROPAGATION OF CONVECTION TOWARD THE COAST. HOWEVER...GIVEN THE INFLUENCE OF AN ONLY WEAK UPSTREAM PERTURBATION APPROACHING FROM THE MID-MS VALLEY PER WATER VAPOR IMAGERY...AND THE LACK OF EVEN STRONGER BUOYANCY...ANY SVR RISK IS CURRENTLY EXPECTED TO REMAIN ISOLATED. ..COHEN/CORFIDI.. 05/25/2014 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...ILM...CHS...CAE...GSP...MRX...FFC...OHX...HUN... LAT...LON 31658139 32788279 34418493 35918679 35798457 34688201 33677996 32957948 31658139 NNNN