005 FXUS61 KBGM 191740 AFDBGM Area Forecast Discussion National Weather Service Binghamton NY 140 PM EDT Mon Aug 19 2019 .SYNOPSIS... Isolated to scattered afternoon thunderstorms may pop up mainly along or east of Interstate 81. A small chance of thunderstorms will linger in Northeast Pennsylvania Tuesday, but thunderstorms are much more likely Wednesday as a cold front sweeps through the region. && .NEAR TERM /THROUGH TUESDAY/... 1000 am update...Water Vapor imagery shows that an upper level wave was moving through NY/PA as of late this morning. A prefrontal surface trough was presently moving east through central NY / northeast PA. Surface dewpoints were down into the mid 60s behind this trough with surface dewpoints closer to 70F ahead of the trough. Mixed layer CAPEs ranged from 500 to over 2000 J/kg across eastern PA to NJ with CAPES generally less than 500 J/kg over northeast PA / central NY. There still was considerable convective inhibition. As diurnal heating continues this afternoon all CIN will be removed and lifting ahead of this wave should fire another rough of strong to severe thunderstorms especially from the Catkills to northeast PA. These areas likely will be the genesis region for more significant storms southeast of our forecast area. Believe that another area of isolated to scattered showers and storms will develop and move east across the area by this evening as well along the actual cold front. This activity will be less widespread and likely not severe. Have updated grids with new timing in hourly POPs based on hi resolution CAMs. 315 AM update... Isolated severe thunderstorms will be possible this afternoon generally east of I-81 in Northeast PA, and into the Catskills of NY. Warm and humid conditions are also in store for mainly the Twin Tiers southward today. Adjustments were made to the forecast for today, based on what is happening in the mesoscale. Decaying line of convection will sweep through mainly Central New York early this morning. Subsidence behind the associated wave will lower chances of showers and thunderstorms compared to previous expectations, for most of the area today. Diurnal heating may still muster isolated to scattered afternoon thunderstorms, with areas east of Interstate 81 in Northeast PA and south of Interstate 88 in Central NY having the somewhat better chances of that. Overall, we are anticipating things to be quieter compared to the last few days. It will however be fairly warm and humid today, with heat indices at lower elevations achieving mid 80s to near 90 in Central NY and lower to mid 90s in Northeast PA. Southwest to west winds will pick up a bit behind the wave late morning through afternoon to take the edge off of that somewhat. Operational models are skewing towards a ECMWF-type solution for Tuesday, in allowing surface high pressure and drier low precipitable water (Pwat) air mass to put a hold on our recent busy weather pattern. A Pwat gradient will exist south of the NY-PA border, and thus we cannot completely remove chances of convection from Northeast PA-Sullivan County NY, but forecast has been adjusted lower. Large majority of the area will be dry Tuesday. Dewpoints will also dip into only upper 50s-lower 60s from Twin Tiers northward, and mid 60s further south, though that will be temporary. && .SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/... A trough over Eastern Canada will push a boundary across NY and PA on Wednesday. Warm and humid conditions are forecast ahead of this storm system with instability strengthening into the afternoon hours. Solid bulk shear values and a dynamic wind profile for mid-August highlight this weather scenario. Strong to severe storms are possible Wednesday and Wednesday evening. && .LONG TERM /THURSDAY THROUGH SUNDAY/... A low pressure system will spin across Northern NY on Thursday and keep a chance for a shower or thunderstorm in the forecast. Cool, northerly flow is forecast for Friday, leading to a pleasant sunny day across the region. The clear and quiet weather will continue through at least Saturday. Warmer, more humid air will push into the Ohio Valley on Sunday. It appears precipitation will remain west of our forecast area through Sunday afternoon, but the timing could change. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... We have VFR in broken cumulus for the afternoon. We don't have enough confidence to put thunder or restrictions in any terminals. From the visible satellite imagery the cumulus were clumping along the Lake Ontario breeze. Cumulus will be broken most of the afternoon and then thin out and vanish by sunset. For overnight skies will be mainly clear and with light winds we expect more valley fog and have VLIFR FG at KELM and IFR BR at KBGM with MVFR BR at KITH. Rest of terminals VFR. Winds will be westerly 5 to 10 knots this afternoon and mainly calm tonight. Outlook... Tuesday Afternoon...Small chance of a thunderstorm at KAVP Tuesday afternoon. Otherwise VFR. Tuesday night through Wednesday night...Restrictions possible in showers and storms, especially Wednesday afternoon-evening. Thursday through Saturday...VFR conditions likely. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...DJN/MDP NEAR TERM...DJN/MDP SHORT TERM...DJP LONG TERM...DJP AVIATION...DJN