ZCZC SPCSWOMCD ALL ACUS11 KWNS 231834 SPC MCD 231834 NJZ000-PAZ000-DEZ000-MDZ000-DCZ000-VAZ000-WVZ000-OHZ000-232100- MESOSCALE DISCUSSION 1372 NWS STORM PREDICTION CENTER NORMAN OK 0134 PM CDT SAT JUL 23 2016 AREAS AFFECTED...SRN PA...SRN NJ...DE...MD...DC...NRN VA...NRN/ERN WV...EXTREME ERN OH CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 231834Z - 232100Z PROBABILITY OF WATCH ISSUANCE...20 PERCENT SUMMARY...THUNDERSTORM DEVELOPMENT IS EXPECTED LATER THIS AFTERNOON WITH A THREAT OF ISOLATED DAMAGING WIND. WATCH ISSUANCE IS CURRENTLY NOT ANTICIPATED. DISCUSSION...AT 1830Z...A GRADUALLY DEEPENING CU FIELD IS EVIDENT ON VIS IMAGERY ACROSS ERN OH INTO WRN/CNTRL PA...ALONG AND SOUTH OF A WEAK COLD FRONT...WITH ATTEMPTS AT INITIATION NOTED NEAR AND EAST OF PITTSBURGH. LARGE-SCALE ASCENT IS LARGELY ABSENT ACROSS THIS REGION...OTHER THAN PERHAPS THE GLANCING INFLUENCE OF A VORT MAX CURRENTLY MOVING INTO NEW ENGLAND...AND LOW-LEVEL CONVERGENCE IS WEAK...SO COVERAGE OF DEEP CONVECTION IS STILL UNCERTAIN. HOWEVER...CONTINUED STRONG HEATING SHOULD EVENTUALLY SUPPORT ISOLATED TO WIDELY SCATTERED TSTM DEVELOPMENT ALONG/AHEAD OF THE FRONT ACROSS THE AREA...WHICH WILL MOVE SEWD THROUGH THE AFTERNOON. LATEST MESOANALYSIS INDICATES MLCAPE OF 1500-2000 J/KG ACROSS THE AREA SOUTH OF THE FRONT...WHILE NWLY MIDLEVEL FLOW IS SUFFICIENT FOR 25-35 KTS OF EFFECTIVE SHEAR...WHICH WILL SUPPORT SOME ORGANIZED STORM STRUCTURES WITH THE STRONGEST UPDRAFTS. THE LACK OF LARGE-SCALE ASCENT WILL LIKELY LIMIT THE COVERAGE AND MAGNITUDE OF THE SEVERE THREAT COMPARED TO WHAT NORMALLY WOULD BE SUPPORTED BY THE INSTABILITY/SHEAR COMBINATION...BUT SOME DAMAGING WIND GUSTS WILL BE POSSIBLE GIVEN STEEP LOW-LEVEL LAPSE RATES AND FAVORABLE DCAPE. WATCH ISSUANCE IS CURRENTLY NOT ANTICIPATED. ..DEAN/WEISS.. 07/23/2016 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...PHI...AKQ...CTP...LWX...PBZ...RLX...CLE... LAT...LON 39187957 39838048 40278104 41078092 40737966 40657849 40527769 40307666 40097580 39947522 39517488 39187485 38877508 38637586 38417650 38307717 38437769 38607810 39187957 NNNN