428 FXUS61 KBGM 192311 AFDBGM Area Forecast Discussion National Weather Service Binghamton NY 711 PM EDT Tue Sep 19 2023 .SYNOPSIS... High pressure will build in Wednesday, then last into Friday, bringing fair weather and warm daytime temperatures. Nights may be chilly with plenty of 40s for overnight lows, and even some 30s in the normally colder spots. && .NEAR TERM /THROUGH WEDNESDAY NIGHT/... 6 pm update... The lake effect light rain showers have dried up and moved northeast. Removed the showers in Oneida and Otsego now forward. Adjusted sky cover mostly down in CNY. Lowered dewpoints this evening. Rest of forecast in good shape. Lower clouds go away and valley fog forms as temperatures fall into the 40s and a few 30s. High clouds come in for the overnight but shouldn't matter much to the lows and fog. 215 PM Update: Quiet weather is expected for the middle of this week. Surface high pressure builds into the area tonight and crests directly overhead of CNY by early Thursday morning. The main forecast focus therefore revolves around diurnal temperature trends and the ins and outs of late night/early morning fog and low clouds. Clouds from today will dissipate this evening and then the expectation is for good radiational cooling to occur both tonight and Wednesday night with temperatures dropping into the low-mid 40s along with some upper 30s outliers in the normally coldest locations tonight. Wednesday night looks a tad colder with outlier mid 30s definitely in the offering. If that trend continues and becomes more widespread, we may have to consider highlighting a risk of frost later on, but confidence is low at this point in time. Will be blending in some of the NBM 10% probability temperature guidance to capture the magnitude of cooling next two nights. Clear and cool nights will also lead to dense valley fog and stratus and we'll continue that in today's update. Flow above the decoupled boundary layer is going to remain from the north which is upslope into CNY therefore we could see just enough lift to trigger some patchy drizzle. In fact, the NAM 12km guidance suggests light QPF over CNY at 12Z Thursday. Interesting. Wall to wall sunshine and 65 to 72 degrees looks to be the call for Wednesday after the morning fog lifts. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... 225 PM Forecast... Wonderful fall weather will be the name of the game for this period as a strong high pressure system is expected to cover the region. Plenty of sunshine on Thursday will allow temps to climb into the upper 60s to mid 70s. Thursday night will see mostly clear skies, light to calm winds and dry air provide a nice radiational cooling setup that will force temps into the low to mid 40s. A few of the historically colder valleys in the Catskills could see upper 30s. On Friday, the high will slowly slide eastward, bringing a mores southerly component to the wind field and allowing a slightly warmer airmass to move into the area. This will push highs into the low to mid 70s. Conditions will continue to be dry but thanks to the shift eastward, a little more humidity will creep into the region, pushing dewpoints up about 5 degrees( low 50s) from where they were on Thursday. Friday night will continue to be dry as high pressure will remain overhead but an increase in clouds from the south will keep lows in the upper 40s to low 50s. && .LONG TERM /SATURDAY THROUGH TUESDAY/... 230 PM Forecast... A developing low pressure system off the SE coast will be the main weather feature to be watching for this period. A low with sub-tropical characteristics is expected to develop off the GA/SC coast on Friday. Model guidance is still very unsure as to the timing and path of the low once it develops. GFS ensembles and deterministic are much quicker in bringing the low north than the EURO, but both solutions push the majority of the precipitation to our east. This is thanks to high pressure building into the region from Canada, stifling the northward movement and pushing it eastward by the time it reaches the Mid-Atlantic coastline. One outlier, the Canadian, does not have high pressure north of the region, which allows the low to continue its northern track and bring much heavier and prolonged rain to the region. Given the model trends with the GFS, EURO and NBM, these models were given heavier weight with this forecast. PoPs were slightly increased westward over the region on Saturday and Sat night given the latest GFS ensemble and deterministic drift westward. After this period, the solutions diverge too much to favor one model over the other. NBM guidance was followed for Sunday and Monday given this which brings slight to chance showers across the area. && .AVIATION /23Z TUESDAY THROUGH SUNDAY/... 615 pm update... Mainly clear skies will continue into Wednesday evening giving VFR conditions. KELM is likely to tank to airport minimums in fog and a low ceiling 9 to 13z. It may fall to IFR vsby at times starting at 6z. Fog will burn off by 14z. Fog shouldn't be thick enough to reach AVP or BGM. Light and variable winds tonight. Wednesday west to northwest winds at around 6 kts. Outlook... Wednesday night through Friday night...VFR with local CIG/VSBY restrictions at KELM each morning. Saturday through Sunday...restrictions possible with rain showers. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...JAB/TAC NEAR TERM...JAB/TAC SHORT TERM...JTC LONG TERM...JTC AVIATION...TAC