ACUS3 KMKC 191828 SWOMCD MKC MCD 191827 NYZ000-PAZ000-MDZ000-WVZ000-192100- SPC MESOSCALE DISCUSSION 1828 FOR CONCERNING...SEVERE THUNDERSTORM POTENTIAL... THUNDERSTORMS ARE INTENSIFYING AHEAD OF COLD FRONT FROM WV INTO UPSTATE NY. THIS ACTIVITY MAY REQUIRE ONE OR MORE SEVERE THUNDERSTORM WATCHES WITHIN THE NEXT 1-2 HOURS. DAMAGING WINDS ARE PRIMARY SEVERE RISK. BOUNDARY LAYER CONTINUES TO DESTABILIZE AHEAD OF UPPER LOW FROM WV INTO UPSTATE NY WITH SFC TEMPERATURES NOW INTO THE UPPER 70S TO LOWER 80S. NUMEROUS THUNDERSTORMS ARE DEVELOPING ALONG THE WRN EDGE OF THE WARM CONVEYOR BELT AS IT SHIFTS EWD ALLOWING MUCH DRIER MID LEVEL AIR/POTENTIAL INSTABILITY TO SURGE INTO REGION AHEAD OF APPROACHING COLD FRONT. LOCAL VWP DATA SUGGESTS ADEQUATE SHEAR EXISTS FOR AT LEAST STRONG/SEVERE MULTI CELL UPDRAFTS...WITH ISOLATED SUPERCELLS POSSIBLE...ESPECIALLY OVER WRN PA WHERE SHEAR/INSTABILITY ARE MAXIMIZED. ALTHOUGH LARGE HAIL IS OF SOME CONCERN...IT APPEARS DAMAGING WINDS ARE PRIMARY RISK...ESPECIALLY WITH ANY SUPERCELLS OR LINE SEGMENTS THAT CAN ORGANIZE AND BOW. ..DARROW.. 08/19/01 ...PLEASE SEE WWW.SPC.NOAA.GOV/ FOR GRAPHIC PRODUCT...
ACUS3 KMKC 192032 SWOMCD MKC MCD 192031 KYZ000-MDZ000-WVZ000-PAZ000-192200- SPC MESOSCALE DISCUSSION 1830 FOR NERN KY...WV...WRN PA...MD PANHANDLE CONCERNING...SEVERE THUNDERSTORM WATCH 680...681... ADDITIONAL SEVERE THUNDERSTORM WATCHES WILL LIKELY BE NEEDED DOWNSTREAM FOR PORTIONS OF WRN/CNTRL NY AND CNTRL/ERN PA. LARGE SCALE ASCENT DUE TO LOW LEVEL WARM ADVECTION CONTINUES TO SHIFT SLOWLY ENEWD ACROSS CENTRAL PA AND UPSTATE NY. LOCAL VWP DATA VERIFIES THIS AS GRADUAL VEERING IN LOW LEVELS WITH INCREASINGLY UNIDIRECTIONAL FLOW IS OBSERVED. REGIONAL RADAR DATA SUGGESTS 70-100 MI WIDE ZONE OF CONVECTION IS SHIFTING EWD AT ROUGHLY 15 KT...SUGGESTING SEVERE THREAT WILL MOVE NORTH AND EAST OF WW 680 SHORTLY. ..DARROW.. 08/19/01 ...PLEASE SEE WWW.SPC.NOAA.GOV/ FOR GRAPHIC PRODUCT...
ACUS3 KMKC 192237 SWOMCD MKC MCD 192236 PAZ000-NYZ000-200030- SPC MESOSCALE DISCUSSION 1832 FOR CENTRAL/NRN PA AND S-CENTRAL NY CONCERNING...SEVERE THUNDERSTORM WATCH 682... LINE OF THUNDERSTORMS EXTENDING FROM 45 E BFD TO 5 NW AOO AT 19/22Z WILL MOVE GENERALLY 240/25KT THROUGH CENTRAL/NRN PA DURING THE NEXT SEVERAL HOURS. TWO ISOLATED SUPERCELL THUNDERSTORMS AHEAD OF THE LINE OVER LYCOMING AND CENTRE COUNTIES IN PA WILL ALSO MOVE NEWD...WITH THE THREAT OF DAMAGING WINDS AND MARGINALLY SEVERE HAIL. WEAK STORM ROTATION WAS ALSO EVIDENT WITH CELL OVER CENTRAL STEUBEN COUNTY NY AT 2230Z. WIND DAMAGE IS THE MAIN THREAT WITH REMAINING ACTIVITY ACROSS THE WW 682 AREA. SURFACE DEWPOINTS IN THE MIDDLE 60S IN ADVANCE OF ONGOING CONVECTION IS CONTRIBUTING TO 100MB MLCAPE VALUES OF 500-1000 J/KG AT 19/22Z. DESPITE ONLY WEAK TO MODERATE INSTABILITY...VAD WIND PROFILES FROM BUF AND PBZ INDICATE 2-3KM SWLY WINDS BETWEEN 30- 40KT...WHICH WILL ENHANCE THE THREAT OF DAMAGING WIND GUSTS ACROSS THE WATCH AREA. DEEP LAYER SHEAR IS MARGINALLY SUPPORTIVE OF SUPERCELLS...AND ROTATING UPDRAFTS WILL LIKELY ENHANCE POTENTIAL FOR SEVERE HAIL AHEAD OF MAIN ACTIVITY. STORMS EXCEEDING SEVERE LIMITS AT TIMES ARE LIKELY DURING THE NEXT 2-4 HOURS...AFTER WHICH TIME DIURNAL COOLING IN THE BOUNDARY LAYER SHOULD RESULT IN A GENERAL WEAKENING OF CONVECTION BY LATE THIS EVENING. ..BANACOS.. 08/19/01
