402 FXUS61 KBGM 162329 AFDBGM Area Forecast Discussion National Weather Service Binghamton NY 729 PM EDT Wed Apr 16 2025 .SYNOPSIS... Lake effect snow is becoming lighter and will end this evening. Tomorrow will be still a bit cool but sunny skies are expected region wide with winds becoming lighter as high pressure builds in. Friday into Saturday will continue to see warming weather though unsettled weather returns this weekend. && .NEAR TERM /THROUGH THURSDAY NIGHT/... 635 PM Update... Temperatures have cooled slightly quicker than originally anticipated as most of the region is now in the 30s with the exception of the Wyoming Valley. Adjustments were made to get the forecast closer to the latest observations. Slight adjustments were also made to PoPs to better capture what is being observed on radar as lake effect precipitation continues. The afternoon discussion mentioned that warmer 850mb air gets advected in and while models do show a slight warm up at that level late this evening, it is not much of one. Some guidance keep showers around longer than originally forecasted, though if the slightly warmer temps do not end the snow showers/flurries, the drier air moving in likely will. The final decision was to not extend PoPs later than the afternoon update, but this may be something worth monitoring later tonight. 145 PM Update... Cold air advection over Lake Ontario continues to lead to late season lake effect snow. Temperatures are slowly creeping up at the surface with the solar heating despite 850 mb temperatures still slowly dropping. Webcams around the Finger Lakes into CNY show the snow that fell this morning is melting and with the coldest air aloft moving east of the region later this afternoon, the winter weather advisories ending time was brought up to 2 pm rather than 8pm. Tonight, despite the continued NW flow, warmer temperatures at 850 mb begin to advect in with the lake effect snow coming to an end shortly after sunset. Temperatures remain cold at the surface but low clouds and wind keeps the boundary layer mixed so we wont have too much radiational cooling to plunge lows into the low 20s. High pressure builds in tomorrow with skies quickly clearing out after sunrise. With full sun, temperatures will likely warm more than modeled so the NBM 90th was used for day time temperatures. Forecast soundings show a subsidence inversion above the boundary layer so that means the sun would only have to heat the lowest 4000 to 6000 feet rather then if we had deep, steep lapse rates where it would take a lot more heating through a deeper atmosphere to get a temperature increase. There is also a very dry layer above the boundary layer as well so as deeper mixing occurs, that dry air will mix into the boundary layer so dew points were lowered well below most models. The Canadian regional had the lowest dew points so that was used and then dew points lowered a few more degrees based on potential mixing heights in bufkit. The surface high moves overhead tomorrow night and with clear skies initially and calm winds, radiational cooling will drop temperatures quickly after sunset with the temperature blend going from near the 90th percentile an hour before sunset to a mix of the mean and 10th percentile a few hours after sunset. Mid and high clouds begin to move in around midnight and slows the cooling and may help stabilize temperatures as warm air advection begins aloft. Still, tomorrow night may be colder than tonight given the clear skies and light winds. && .SHORT TERM /FRIDAY THROUGH SATURDAY/... 240 PM Update... A broad mid level trough moves into the region Friday morning, with a ridge over the SE US. This brings Southerly flow and pushes a warm front into the area from the SW. Temps Friday will be very warm, climbing into the mid to upper 60s. Rain showers should develop along the warm front, spreading north and east as the day progresses. Coverage in the morning is still uncertain, especially east of the Finger Lakes. The warm front will clear the area by the evening, pushing most of the rain showers north of the region during the evening and into the overnight hours. Overnight lows will be very warm as WAA behind the front continues, with lows only in the mid 50s to low 60s. On Saturday, the approaching upper trough digs to the SW and stays positively tilted as it runs into a strong ridge over the SE that is slowly sliding eastward. This sets up a stationary boundary running from the Montreal area SW through the eastern Great Lakes into the south central US. A series of shortwaves will ride this boundary, producing rain showers a across our CWA Saturday. A few thunderstorms may develop north of the Southern Tier during the afternoon hours. The stationary boundary slowly slides eastward and becomes a cold front late in the day Saturday. Highs on Saturday will be extremely warm for this time of year, with highs in the upper 60s to upper 70s. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... 315 PM Update... More normal temperatures are expected Sunday after the cold front moves through. There could be some lingering showers on Sunday, but confidence in this is low as guidance is showing a wide variety of solutions. The aforementioned positively tilted trough looks to dig into the south central US Sunday and quickly become more positively tilted and generate a strong mid-level cutoff low that will push into the Great Lakes region by Monday morning. The timing and track of this low is still uncertain as guidance has differences in how far south the upper trough digs and how quickly the mid- level low cuts off and moves to the NE. Even with these differences, it looks like rain showers should move into the area Monday into Tuesday morning. Temps during this period are not modeled well, with 4-6 standard deviations in highs and lows. Because of this, had to stick with NBM data that keeps temps seasonable through the beginning of the week. && .AVIATION /23Z WEDNESDAY THROUGH MONDAY/... Lake effect snow will come to an end this evening though MVFR ceilings will linger slightly longer. All terminals will become VFR by 06-07z and then skies clear out during the daytime. West-northwest winds remain gusty through the late afternoon tomorrow but should become slightly calmer overnight. Peak gusts will initially be as high as 25 kts this evening but should decrease to 15 to 20 kts overnight. Winds are expected to become calm by the end of the TAF period. Outlook... Thursday night...Likely VFR. Friday...Afternoon showers possible in NY along with associated restrictions. Saturday...Showers likely with isolated thunderstorms and associated restrictions possible. Sunday...Mainly VFR. Sunday Night into Monday...Chance (<50%) of showers and any restrictions. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...AJG NEAR TERM...AJG/BTL SHORT TERM...JTC LONG TERM...JTC AVIATION...BTL