202 FXUS61 KBGM 020154 AFDBGM Area Forecast Discussion National Weather Service Binghamton NY 954 PM EDT Thu Aug 1 2019 .SYNOPSIS... High pressure will be in charge through Friday with mostly clear skies. Though isolated showers and thunder are possible over the weekend, overall the weather looks mainly dry with seasonal temperatures. && .NEAR TERM /THROUGH FRIDAY NIGHT/... 945 PM UPDATE... Very little change to the forecast this evening under mainly clear skies. Have adjusted the temperatures a bit and lowered the winds to near calm. Still expect valley fog to develop after midnight with the light winds. Previous discussion below. Tonight...High pressure situated over southern Ontario will bring the area clear skies overnight along with cooler temperatures. Valley fog will form late tonight across the southern tier, western Catskills and northeast Pennsylvania. Overnight lows will range in the mid 50s to around 60. Friday...Another mainly dry day with plenty of sunshine. High pressure will move off the New England bringing a return flow of slightly warm air. A mid level short wave moving through the mid Atlantic region and diurnal instability will bring a slight chance/chance for thunderstorms across much of northeast Pennsylvania and the central southern tier. Highs will range in the upper 70s to mid 80s. Friday night...Loss of diurnal heating will end most convective activity across the south but still cannot rule out an isolated thunderstorm in the far southeast especially in the higher terrain. Otherwise, a dry period with mainly clear skies and lows in the upper 50s to lower 60s. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... Weak short wave aloft passes across NY and PA by Saturday afternoon. The models are subtle with this feature. The main effect of this will be to advect low-level moisture northward leading to increased low-level moisture Saturday morning. Dewpoints at 850 mb climb to the low 50s, near 60F at 925 mb and low to mid 60s at the surface. This moistening precedes a weak cold front that will move through the region by Saturday evening and weaken across the twin tiers. The lifting and dynamics are not that impressive given the weak nature of the short wave but mixed layer CAPEs will be between 1000 and 2000 J/kg mainly south of a line from UCA to ELZ in the BGM forecast area in the afternoon. Wind shear isn't that impressive either. Model sounding data shows quite a bit of dry air aloft and weak shear suggesting pulse type storms. Used a blend of models to arrive at POPs. Think it will be isolated coverage from the Finger Lakes northeast to upper Mohawk Valley and scattered coverage rest of south central NY / northeast PA and the Catskills. POPs reflect this thinking for Saturday. Activity will wind down in the evening Saturday with the loss of the day's heating and weak cold / dry air advection. The NAM / GFS and Euro suggest some scattered stratocumulus clouds advecting south across central NY and most of northeast PA by Sunday morning. For Sunday, a low-level dewpoint gradient will exist across the NY/PA border region as per the model guidance with higher dewpoints farther south. At upper levels strong confluence sets up to our east which favors large scale descent. With lingering low-level moisture and some heating there could be some isolated showers or storms mainly across northeast PA and the southern tier. Believe most of the activity will be in the afternoon as per model soundings. But a capping inversion is projected to develop from the above mentioned broad scale subsidence so coverage likely will be limited to higher terrain. For Sunday night, high pressure builds across the region with light winds. It looks like a perfect night for valley fog formation and have in grids. && .LONG TERM /MONDAY THROUGH THURSDAY/... Monday looks fair as next complex system brews to our south and northwest. By Tuesday, a short wave and associated front moves into the Great Lakes region increasing chances for showers and a few storms. Wednesday and Thursday look more unsettled as an upper level trough moves into the eastern U.S with numerous short waves. Used NBM as a starting point and blended with neighboring WFOs. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... Area of high pressure will dominate the next 24 hours with VFR conditions at all forecast terminals except KELM where valley fog may produce early morning restrictions. Valley fog is still expected to develop between 06-08Z with conditions near airport mins between 08-13Z. Otherwise, clear skies tonight and another round of fair weather cumulus Friday afternoon around 4-6K feet. Generally light and variable winds through the TAF period. Outlook... Friday night through Tuesday...Mainly VFR other than potential typical predawn fog each morning at KELM. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...DGM/RRM NEAR TERM...DGM/RRM SHORT TERM...DJN LONG TERM...DJN AVIATION...BJT/RRM