ZCZC SPCSWOMCD ALL ACUS11 KWNS 281844 SPC MCD 281844 VAZ000-NCZ000-282015- MESOSCALE DISCUSSION 1739 NWS STORM PREDICTION CENTER NORMAN OK 0144 PM CDT WED SEP 28 2016 AREAS AFFECTED...PORTIONS OF SRN/ERN VA AND NC CONCERNING...SEVERE POTENTIAL...WATCH LIKELY VALID 281844Z - 282015Z PROBABILITY OF WATCH ISSUANCE...80 PERCENT SUMMARY...THE SEVERE THREAT...INCLUDING A RISK FOR STRONG TO LOCALLY DAMAGING WINDS AND ISOLATED TORNADOES...IS INCREASING. WW ISSUANCE IS LIKELY. DISCUSSION...RECENT VISIBLE SATELLITE AND RADAR IMAGERY INDICATE AN INCREASE IN CONVECTION ACROSS THE MCD AREA AS FILTERED DIURNAL HEATING HAS OCCURRED ALONG/S OF A FRONTAL BOUNDARY EXTENDING FROM WRN NC NNEWD INTO PARTS OF SRN/ERN VA. WHILE SLY LOW-LEVEL WINDS ARE RELATIVELY WEAK ATTM PER 18Z SFC OBSERVATIONS AND AREA VWPS...THEY ARE FORECAST TO STRENGTHEN SOMEWHAT THROUGH THE REMAINDER OF THE AFTERNOON INTO THIS EVENING AS AN UPPER LOW OVER IND CONTINUES MOVING SWD. WINDS DO STRENGTHEN/VEER WITH HEIGHT AT MID-LEVELS... WITH LATEST RAP MESOANALYSIS SUGGESTING EFFECTIVE BULK SHEAR VALUES GENERALLY RANGE FROM 35-45 KT. A VERY MOIST LOW-LEVEL AIRMASS ALONG WITH SOME SFC HEATING HAS ALLOWED MLCAPE TO INCREASE BETWEEN 1000-1500 J/KG. THIS COMBINATION OF INSTABILITY AND SHEAR WILL BE SUPPORTIVE OF SOME SUPERCELL STRUCTURES AND PERHAPS BOWING SEGMENTS...WITH STRONG TO LOCALLY DAMAGING WINDS AND ISOLATED TORNADOES POSSIBLE. ..GLEASON/HART.. 09/28/2016 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...AKQ...RAH...RNK...GSP... LAT...LON 35758112 37157921 37837801 37827709 37497631 37067627 36527656 35097895 35187998 35758112 NNNN