Mesoscale Discussion 466

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MESOSCALE DISCUSSION 0466 NWS STORM PREDICTION CENTER NORMAN OK 1244 PM CDT SUN APR 26 2015 AREAS AFFECTED...MUCH OF SC CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 261744Z - 261945Z PROBABILITY OF WATCH ISSUANCE...20 PERCENT SUMMARY...AN ISOLATED DAMAGING WIND THREAT MAY DEVELOP THIS AFTERNOON ACROSS MUCH OF SC. WW ISSUANCE IS UNLIKELY. DISCUSSION...A SLOWLY SWWD MOVING COLD FRONT ACROSS SC SHOULD PROVIDE A FOCUS FOR ISOLATED TO WIDELY SCATTERED THUNDERSTORM DEVELOPMENT THIS AFTERNOON. SFC TEMPERATURES ALONG AND S OF THIS FRONT HAVE WARMED INTO THE UPPER 70S TO LOWER 80S AS OF 17Z...WITH DEWPOINTS GENERALLY IN THE 60S ACROSS MUCH OF UPSTATE SC. AS THE BOUNDARY LAYER CONTINUES TO WARM FOR THE NEXT SEVERAL HOURS...MLCAPE SHOULD INCREASE UP TO 1000-1250 J/KG GIVEN MIDLEVEL LAPSE RATES AROUND 6.0-6.5 C/KM. UNIDIRECTIONAL WLY FLOW STRENGTHENING WITH HEIGHT THAT IS ROUGHLY PARALLEL TO THE SFC BOUNDARY MAY PROMOTE INITIAL SUPERCELL DEVELOPMENT THAT COULD GROW UPSCALE INTO MULTICELL/BOWING STRUCTURES...WITH AN ASSOCIATED RISK FOR STRONG TO ISOLATED DAMAGING WIND GUSTS...AND PERHAPS SOME HAIL. AREA RADARS DEPICT ELEVATED SHOWERS THAT HAVE RECENTLY FORMED OVER CHEROKEE COUNTY SC TO THE COOL SIDE OF THE FRONT...WHICH COUPLED WITH A DEEPENING CUMULUS FIELD ON VISIBLE SATELLITE...MAY SIGNAL THAT CONVECTION WILL DEVELOP WITHIN THE NEXT HOUR OR TWO. REGARDLESS...THE MARGINAL THERMODYNAMIC ENVIRONMENT WILL PROBABLY ACT TO LIMIT A MORE ROBUST SEVERE THREAT ACROSS THE MCD AREA THIS AFTERNOON. THEREFORE...WW ISSUANCE IS UNLIKELY AT THIS TIME. ..GLEASON/MEAD.. 04/26/2015