ZCZC SPCSWOMCD ALL ACUS11 KWNS 211611 SPC MCD 211611 NCZ000-SCZ000-211745- MESOSCALE DISCUSSION 0713 NWS STORM PREDICTION CENTER NORMAN OK 1111 AM CDT THU MAY 21 2015 AREAS AFFECTED...E-CNTRL AND ERN NC / SC GRAND STRAND CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 211611Z - 211745Z PROBABILITY OF WATCH ISSUANCE...60 PERCENT SUMMARY...SCATTERED STORMS ARE FORECAST TO DEVELOP OVER THE NEXT FEW HOURS. AN ISOLATED SEVERE THREAT WILL LIKELY DEVELOP AND A WATCH WILL STRONGLY BE CONSIDERED. DISCUSSION...SUBJECTIVE SURFACE MESOANALYSIS PLACES A LOW 30 MI W SOP WITH A WEST-EAST ORIENTED WARM FRONT AND A TRAILING COLD FRONT ACROSS THE SC PIEDMONT. A PREFRONTAL CONFLUENCE/SURFACE TROUGH EXTENDS FROM THE LOW SEWD THROUGH THE GRAND STRAND VICINITY. OBSERVATIONS TO THE E OF THE SURFACE TROUGH AND LOCATED WITHIN THE WARM SECTOR SHOW TEMPS WARMING TO NEAR 80 DEG F WITH BOUNDARY LAYER DEWPOINTS IN THE MID-UPPER 60S INLAND AND AROUND 70 NEAR THE COAST. SUPER RAPIDSCAN VISIBLE IMAGERY SHOWS A BUILDING TCU FIELD IMMEDIATELY E OF THE LOW AND ALONG THE PREFRONTAL TROUGH/CONFLUENCE. WATER VAPOR IMAGERY LATE THIS MORNING IMPLIES A WEAK LEAD DISTURBANCE MOVING ACROSS W-CNTRL NC AHEAD OF THE MID MS VALLEY SHORTWAVE TROUGH FORECAST TO APPROACH THE CNTRL APPALACHIANS LATER TODAY. IT SEEMS THE WEAK UPPER FORCING FOR ASCENT PROVIDED BY THE LEAD IMPULSE COUPLED WITH ADDITIONAL DIABATIC HEATING WILL ERODE THE CAP OVER THE NEXT 1-2 HOURS AND SCATTERED STORM COVERAGE IS PROBABLE BY THE 18-19Z TIMEFRAME. VEERING AND A GRADUAL STRENGTHENING OF WINDS WITH HEIGHT WILL SUPPORT STORM ORGANIZATION ONCE A FEW VIGOROUS UPDRAFTS BECOME ESTABLISHED. FORECAST SOUNDINGS DEPICT MODERATE BUOYANCY AS OF 16Z ACROSS THE WARM SECTOR AND THIS SHOULD FAVOR STORM INTENSIFICATION OVER THE NEXT SEVERAL HOURS ONCE INITIATION COMMENCES. ISOLD LARGE HAIL AND DMGG WINDS WILL BE THE PRIMARY THREATS. DESPITE TEMPERED LOW-LEVEL SHEAR...A TORNADO MAY ALSO BE POSSIBLE ESPECIALLY IF A SUPERCELL CAN DEVELOP AND FAVORABLY TRACK ALONG THE WARM FRONT. ..SMITH/THOMPSON.. 05/21/2015 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...AKQ...MHX...RAH...ILM...CAE... LAT...LON 35267979 36097844 36297643 35847549 34977597 33737851 33897960 34497991 35267979 NNNN