Mount St. Louis Moonstone Snow Report

642 FXUS61 KBUF 130635 AFDBUF Area Forecast Discussion National Weather Service Buffalo NY 235 AM EDT Sun Sep 13 2026 .WHAT HAS CHANGED... Minor changes to the forecast with this update. && .KEY MESSAGES... 1) Warm and humid conditions will continue today, with showers and scattered thunderstorms through this evening. 2) Brief cooldown Monday through early Tuesday morning, then trending warmer and unsettled through the middle of the week. && .DISCUSSION... KEY MESSAGE 1...Warm and humid conditions will continue today, with showers and scattered thunderstorms through this evening. GOES water vapor imagery shows a southern stream shortwave trough across Pennsylvania early this morning. An axis of PWATS over 1.5 inches within a region of strong moisture transport has moved east of the forecast area. Steady showers have exited the Southern Tier, though showers will continue across the Finger Lakes and north- central NY early this morning. A very moist airmass will remain across the forecast area, with dewpoints remain in the mid to upper 60s. Patchy fog and stratus are expected through daybreak. A surface trough is expected to move across the region this morning, and a few showers can`t be ruled out due to weak low-level convergence. A strong northern stream trough will move into the Great Lakes region today with an associated cold front approaching the forecast area before passing through this evening. Instability will develop across most of the region today. A southwest wind will likely shadow areas downwind of the Lakes, keeping conditions mostly dry there. Showers and scattered thunderstorms are expected to develop along and inland from lakebreeze. Forecast soundings suggest increasing mid-level winds and steepening mid-level lapse rates ahead of the cold front. Isolated severe thunderstorms are possible with damaging winds and large hail as the primary hazards. The main area of concern is the inland areas of the western Southern Tier extending to the Finger Lakes region. Most showers and thunderstorms will be progressive, though brief heavy downpours are possible. Some HREF members show a line of heavy showers and thunderstorms developing across the Niagara Pennsiula to the Niagara Frontier this afternoon. A narrow region of localized heavy rain and an isolated severe thunderstorm are possible. The cold front and the leading edge of the trough will move across the region this evening. A ribbon of mid-level moisture will maintain chances for showers. Cold air advection and drier air will filter into the region tonight, with 850mb temperatures tumbling through Monday morning. KEY MESSAGE 2...Brief cooldown Monday through early Tuesday morning, then trending warmer and unsettled through the middle of the week. Drier and much cooler weather will settle across the region Monday through Monday night. Northwest flow and 850mb temperatures bottoming out to as low as +3C will result in below normal temperatures. High temperatures will range from the mid to upper 60s, to the lower 60s across the higher terrain. Surface high pressure will move across the region Monday night. Temperatures will fall into the 40s, with the potential for locations across the Southern Tier valleys and Tug Hill region to reach the upper 30s. Patchy frost can`t be ruled out across portions of Lewis county Monday night. An upper level ridge will build briefly across the Great Lakes region Monday night through Tuesday before settling south of the region through mid-week. Warmer weather will return to the region as a frontal boundary with increasing moisture stalls near the forecast area. This may bring periods of showers and thunderstorms through Thursday. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... Widespread low clouds are expected with ceilings varying between MVFR across the lower elevations to IFR/LIFR across the higher terrain this morning. An area of showers will exit north-central NY early this morning, mainly staying east of KART. A warm and humid airmass will remain across the region today. Lower ceilings will linger through the morning, before improving to VFR this afternoon. Another round of showers and scattered thunderstorms is expected across inland locations this afternoon into this evening. Brief downpours and MVFR to LIFR are possible within the showers and especially thunderstorms. Isolated severe thunderstorms are possible, mainly from the inland areas of the western Southern Tier to the Finger Lakes region this afternoon. A brief/erratic surface wind gusts up to 30 to 50 knots can`t be ruled out. A cold front will move across the region tonight. MVFR/IFR ceilings are expected as northwest flow builds into the region. Showers are possible in the evening, with dry conditions late tonight through Monday. Outlook... Monday through Monday night...Dry weather expected. Areas of MVFR CIGS with lake-effect clouds Monday morning, then improving to VFR. Tuesday...Dry weather expected. Localized MVFR to LIFR in early morning valley fog across the Western Southern Tier. Otherwise VFR expected. Tuesday night through Thursday...Periods of showers and thunderstorms with MVFR or worse conditions expected. && .MARINE... Low pressure will move slowly east from Hudson Bay east across Quebec today, with a trailing cold front crossing the lower Great Lakes this evening. Southerly winds will gradually veer to the southwest and west through the day. Northwest winds will increase in the wake of the cold front late tonight through Monday, likely bringing Small Craft Advisory conditions to portions of the lower Great Lakes. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...None. MARINE...None. && $$ DISCUSSION...HSK AVIATION...AR/HSK MARINE...Hitchcock/HSK