Area Forecast Discussion
Issued by NWS Buffalo, NY
Issued by NWS Buffalo, NY
096 FXUS61 KBUF 120635 AFDBUF Area Forecast Discussion National Weather Service Buffalo NY 235 AM EDT Sat Sep 12 2026 .WHAT HAS CHANGED... Minor changes with this forecast update. && .KEY MESSAGES... 1) Warmer and more humid conditions return this weekend with at least periodic chances for some showers and scattered thunderstorms Saturday afternoon through Sunday night. 2) Cool and dry weather expected on Monday, then turning warmer Tuesday, with the next chance for some unsettled weather arriving by midweek. && .DISCUSSION... KEY MESSAGE 1...Warmer and more humid conditions return this weekend with at least periodic chances for some showers and scattered thunderstorms Saturday afternoon through Sunday night. Surface high pressure will cross New England this morning, then move off the east coast later today. A southerly flow will deepen across the region, bringing a warmer and more humid airmass than previous days. A shortwave trough over the Tennessee Valley will move northeast across the Appalachians and Mid-Atlantic today. A surge of deep moisture, with PWATS averagering 1.6inches (80-90th percentile for this time of year) will enter portions of western and north- central NY through this evening. This afternoon, weak surface based instability is expected to develop across far western NY. Showers and isolated thunderstorms are expected from noon through the afternoon. Weak low and mid lapse rates and weak 0-6km shear will support non- severe thunderstorms today. Due to the high moisture content and potential for training storms, there is a low risk of isolated flooding across the western Southern Tier late this afternoon through this evening. HREF 3-hr PMM suggests the potential for an isolated location receiving an inch of rain in 3 hours across the Southern Tier. As the trough moves eastward this evening, showers and isolated thunderstorms are expected to expand into the Finger Lakes region to the southern Tug Hill region, with the threat of flooding east of the region. The warm and humid airmass will persist ahead of a cold front and isolated to scattered showers can`t be ruled out overnight. A deepening upper level trough will move across the Great Lakes region Sunday. A cold front is expected to move across the forecast area. Showers and a few thunderstorms are possible with lingering instability and high dewpoints near the Lakes Sunday morning. Then, surface based instability will develop ahead of the front. Stronger winds aloft will support the potential for an isolated severe thunderstorm with the highest probability from the western Southern Tier to the Finger Lakes region/central NY. Forecast soundings suggest damaging winds and large hail would be the main hazards. Confidence remains low as guidance continues to struggle with the overall coverage of showers and thunderstorms. There remains a chance of showers and a few thunderstorms Sunday night as the main trough axis swings through the region. KEY MESSAGE 2...Cool and dry weather expected on Monday, then turning warmer Tuesday, with the next chance for some unsettled weather arriving by midweek. An upper level trough will dig across the Northeast Monday, with surface high pressure building across the area. A cool, northwest flow will move into the forecast area with mean 850mb temperatures falling to around +4C Monday. Because the airmass is very dry, little lake response is expected. An upper level ridge will build briefly across the Great Lakes region Monday night before flattening out through mid-week. Warmer and more humid air will move back into the region through mid-week. A frontal boundary may stall near the forecast area and bring the potential for periods of showers and thunderstorms through mid-week. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... Besides some cirrus across the western Southern Tier early this morning, clear skies, light winds and dry weather will continue across the region. VFR conditions are expected with the potential for patchy fog in valley locations, however due to a nocturnal jet, fog is less likely across KJHW early this morning. Surface high pressure will move off the east coast today. South winds will increase to 5-12 knots. A shortwave trough and a plume of deep moisture will approach western NY today. Isolated to scattered showers and thunderstorms are expected generally between 15z to 18z across western NY, shifting east through the evening hours. Thunderstorms are mainly expected southeast of roughly KIAG to KART line. MVFR ceilings are expected across the western Southern Tier with low-end VFR ceilings spreading northward this afternoon. Ceilings will lower to MVFR across north-central NY this evening. Brief reductions in visibility are expected in any heavy showers or thunderstorms through tonight. Outlook... Sunday...Isolated to scattered showers and thunderstorms with MVFR or below conditions expected. Sunday night through Monday night...Mainly dry weather and VFR expected. However, scattered lake-effect clouds and isolated showers with MVFR are possible generally southeast and then south of the eastern Great Lakes, especially between KROC and KSYR, overnight Sunday night into Monday morning. Tuesday and Wednesday...Isolated to scattered showers and thunderstorms with MVFR or worse conditions possible. && .MARINE... Surface high pressure will cross the Northeast this morning, providing mainly light winds with little to no wave action through early this morning. Southerly flow will slowly increase today, generally 10-12 knots or below, but up to 15 knots across eastern Lake America. A brief period of marginal SCA conditions will be possible across far eastern Lake America Saturday evening into the first half of the overnight. Flow will veer southwesterly, then westerly ahead of an approaching cold front on Sunday with 10-15 knot winds producing increasingly choppy conditions on both lakes, before winds freshen out of the west and northwest in the wake of the cold frontal passage bringing the potential for a period lower-end SCA conditions Sunday night into Monday. Surface high pressure will move across the region later Monday through Monday night, providing light winds and little wave action. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...None. MARINE...None. && $$ DISCUSSION...HSK AVIATION...HSK MARINE...HSK/77