ZCZC SPCSWOMCD ALL ACUS11 KWNS 101835 SPC MCD 101835 NYZ000-102100- MESOSCALE DISCUSSION 1675 NWS STORM PREDICTION CENTER NORMAN OK 0135 PM CDT SAT SEP 10 2016 AREAS AFFECTED...PORTIONS OF WRN/NRN NY CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 101835Z - 102100Z PROBABILITY OF WATCH ISSUANCE...60 PERCENT SUMMARY...PORTIONS OF WRN/NRN NY ARE BEING MONITORED FOR AN INCREASING RISK OF SVR TSTMS THIS AFTERNOON...INCLUDING TORNADO POTENTIAL. THIS RISK WILL CONTINUE INTO THE EVENING HOURS. THE ISSUANCE OF A TORNADO WATCH MAY BE NECESSARY WITHIN THE NEXT FEW HOURS. DISCUSSION...PRESENT INDICATIONS ARE THAT CONVECTION MAY CONTINUE TO INCREASE ACROSS PORTIONS OF WRN NY IN ASSOCIATION WITH LOW-LEVEL CONFLUENT-FLOW BANDS TRAILING TO THE S OF AN MCV CROSSING THE N SHORE OF LAKE ONTARIO AND ADJACENT PARTS OF ONTARIO. THIS ACTIVITY MAY SPREAD NEWD/ENEWD INTO THE EVENING HOURS. AS THE MCV CONTINUES TRACKING NEWD...OFFERING LOCALIZED AUGMENTATIONS TO LOW/MID-LEVEL FLOW FIELDS TO ENCOURAGE WARM ADVECTION AND THE INCREASE IN CONVECTION...A WARM FRONT WILL CONTINUE TO ADVANCE NEWD THROUGH THE AREA. RECENT EROSION OF BILLOW-CLOUD FORMATIONS HAVE BEEN NOTED FROM SW TO NE...NEAR THE E END OF LAKE ONTARIO AND POINTS EWD. THIS IS INDICATIVE OF THE NEWD MIXING/ADVANCE OF THE WARM FRONT -- ANALYZED FROM W OF SYR TO NEAR BGM AT 18Z. WITH UPPER 60S TO NEAR 70F SFC DEWPOINTS ON THE WARM SIDE OF THE FRONT...COUPLED WITH AT LEAST MODERATE INSOLATION...A CORRIDOR OF MLCAPE AROUND 500-1500 J/KG WILL CONTINUE TO BUILD NEWD ACROSS THE DISCUSSION AREA. THIS COULD SUPPORT VIGOROUS UPDRAFTS DEVELOPING WITHIN THE NEXT FEW HOURS...AS THEY INTERACT WITH 35-45 KT OF EFFECTIVE SHEAR. THIS MAGNITUDE OF DEEP SHEAR MAY SUPPORT DISCRETE/SEMI-DISCRETE SUPERCELLULAR STRUCTURES. FURTHERMORE... RELATIVELY BACKED SFC WINDS -- ESPECIALLY NEAR AND ON THE COOLER SIDE OF THE WARM FRONT -- RESPONDING TO STRONGER SFC PRESSURE FALLS ANALYZED FARTHER N ACROSS PORTIONS OF ONTARIO /2-3 MB PER 2 HOURS/...WILL MAINTAIN AROUND 200-400 M2/S2 OF EFFECTIVE SRH ACROSS THE REGION. THIS WILL SUPPORT THE POTENTIAL FOR SUPERCELL TORNADOES WITH ANY SUSTAINED CONVECTIVE ELEMENTS. ELEMENTS OF UNCERTAINTY REGARDING CONVECTIVE EVOLUTION ARE TIED TO RELATIVELY POOR MID-LEVEL LAPSE RATES THAT SHOULD LIMIT THE RAPIDITY OF CONVECTIVE STRENGTHENING...ALONG WITH THE STRONGEST FORCING FOR ASCENT BEING RELEGATED TO LOCATIONS MUCH FARTHER TO THE W/NW. NEVERTHELESS...OVERLAP OF SUFFICIENT ASCENT...AND FAVORABLE THERMODYNAMIC/KINEMATIC FIELDS FOR CONDITIONAL SUPPORT OF SUPERCELL TORNADOES ALONG WITH DMGG WINDS...WILL EXIST THIS AFTERNOON. SUCH POTENTIAL COULD CONTINUE INTO THE EVENING HOURS...AS A LARGE-SCALE TROUGH LAGS TO THE W OF THE REGION. ..COHEN/GRAMS.. 09/10/2016 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...BTV...ALY...BGM...BUF... LAT...LON 43177719 44227601 44867505 44617429 43797424 42987600 43177719 NNNN