ZCZC SPCSWOMCD ALL ACUS11 KWNS 072035 SPC MCD 072035 NYZ000-PAZ000-MDZ000-WVZ000-OHZ000-VAZ000-KYZ000-072300- MESOSCALE DISCUSSION 1319 NWS STORM PREDICTION CENTER NORMAN OK 0335 PM CDT TUE JUL 07 2015 AREAS AFFECTED...CNTRL APPALACHIANS...LOWER GREAT LAKES CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 072035Z - 072300Z PROBABILITY OF WATCH ISSUANCE...20 PERCENT SUMMARY...A MARGINAL SEVERE THREAT IS EXPECTED ACROSS THE CNTRL APPALACHIAN MTNS AND IN THE LOWER GREAT LAKES REGION THIS AFTERNOON. STRONG GUSTY WINDS WILL BE POSSIBLE AS CELLS INITIATE AND INTENSIFY OVER THE NEXT FEW HOURS. WW ISSUANCE APPEARS UNLIKELY DUE TO THE MARGINAL NATURE OF THE THREAT. DISCUSSION...LATEST SFC ANALYSIS SHOWS A WELL-DEFINED COLD FRONT LOCATED FROM CNTRL IND NEWD TO LAKE ERIE. AHEAD OF THE FRONT...AN AXIS OF LOW-LEVEL MOISTURE IS PRESENT WHERE SFC DEWPOINTS ARE GENERALLY IN THE MID 60S TO LOWER 70S F. AS SFC TEMPS HAVE WARMED INTO THE 80S F ALONG THE MOIST AXIS...MODERATE INSTABILITY HAS DEVELOPED WITH MLCAPE VALUES ESTIMATED IN THE 1000 TO 1500 J/KG RANGE. IN RESPONSE...SCATTERED THUNDERSTORMS HAVE INCREASED IN COVERAGE ALONG THE CORRIDOR OF MODERATE INSTABILITY FROM ERN KY NNEWD INTO WRN PA AND WRN NY. REGIONAL WSR-88D VWPS ALONG THIS CORRIDOR SHOW UNIDIRECTIONAL WIND PROFILES WITH 25 TO 35 KT OF WSWLY FLOW IN THE LOW TO MID-LEVELS...RESULTING IN ABOUT 20 KT OF 0-6 KM SHEAR. THIS MAY BE ENOUGH FOR MARGINALLY SEVERE WIND GUSTS WITH MULTICELLS THAT HAVE ACCESS TO LOCALLY MAXIMIZED INSTABILITY LATE THIS AFTERNOON. ..BROYLES/MEAD.. 07/07/2015 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...BGM...BUF...CTP...RNK...PBZ...RLX...CLE...MRX... JKL...ILN...LMK... LAT...LON 37138159 37228313 37488362 37818400 38358395 39478303 40198245 40908187 42248009 42777936 43117881 43147809 43007736 42857698 42477693 41957726 40867847 39947922 38498033 37998080 37138159 NNNN