Area Forecast Discussion
Issued by NWS Buffalo, NY
Issued by NWS Buffalo, NY
871 FXUS61 KBUF 261418 AFDBUF Area Forecast Discussion National Weather Service Buffalo NY 1018 AM EDT Sat Jul 26 2025 .SYNOPSIS... A slow-moving weak area of low pressure and attendant warm front will bring increasing chances for scattered showers and storms across western NY by this afternoon, then for much of the area tonight. Showers and a few thunderstorms will linger into Sunday morning, then high pressure will bring drier conditions Sunday afternoon into the start of the new work week. Hot and humid weather is set to return for Sunday through Tuesday, peaking on Monday. && .NEAR TERM /THROUGH SUNDAY/... A stalled frontal boundary from northern Illinois to northern Pennsylvania will move north into western NY today. Satellite products show a corridor of deep moisture along the front, with PWATs 200% of normal. Northern edge of precipitation associated with convection across northwestern PA looks as though it will remain just south of the NY/PA line through late this morning, at least the bulk of it. As the front moves northward, surface based instability will increase from the western Southern Tier to the Genesee River today. Isolated to scattered showers and storms are possible in this region. The severe risk is low, with heavy rain in any storms. Further east, a capped environment will keep the region dry. Warm weather will continue with daytime highs in the 80s, upper 80s across the lake plains. A convectively enhanced shortwave trough will move across the region tonight. This could be in the form of a MCV as depicted by some hi- res guidance runs and support an increase in coverage of showers and storms overnight. Deep moisture will persist and produce heavy rainfall in any storms. There are signals that an organized cluster of storms will move into the Eastern Lake Ontario region late tonight. The HREF PMM shows a 50-70% probability of areas near the Tug Hill seeing over an inch of rain in 3 hours. There a lower (30- 50%) chance across interior western NY. Due to the recent dry weather, the risk for localized flooding is low. The mid-level trough and surface low will move east of the forecast area Sunday. The chance for showers and storms will taper off from northwest to southeast through the morning, with mostly dry weather by Sunday afternoon. Warm weather will continue with daytime highs in the 80s, upper 80s across the lake plains. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/... Broad mid-level ridge spanning from the Central Plains to the East Coast Sunday night will remain anchored across the southern portions of the CONUS through Tuesday night. Meanwhile, to the north across the far northern reaches of the CONUS and across much of Canada a shortwave trough will cause a longwave trough to dive southeast across the Upper Great Lakes and into the Central Great Lakes through Tuesday night. Initially ahead of the trough`s arrival, a brief period of mid-level ridging will pass across the eastern Great Lakes region Sunday night through Monday. With the ridging overhead Sunday night through Monday, surface high pressure will work its way across the central and eastern Great Lakes Sunday night through Monday resulting in a period of dry weather for the start of the week. Additionally, with the ridging aloft, 850mb temperatures will warm up towards +19 to +20 degrees Celsius Monday supporting another warm day on tap with highs in the upper 80s across much of the region and some low to mid 90s across the lake plains south of Lake Ontario from Niagara Falls to Rochester and the Genesee Valley. These warm temperatures combined with dewpoints in the upper 60s to low 70s will support heat indices in the mid to upper 90s from the Niagara Frontier to the Genesee Valley. A weak shortwave trough will not only encourage the longwave trough to dive southeast across the Great Lakes, but also introduce a weak cold front to pass east across the Lower Great Lakes Monday night and Tuesday resulting in the next chance for showers and thunderstorms. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... As alluded to in the short term discussion, a pattern shift is on the way for the later half of the week due to the longwave trough deepening across eastern Canada, the Great Lakes and the Northeastern States. After a cold frontal passage mid-week, surface high pressure will lie across the Great Lakes late in the week. All in all, chances for showers and thunderstorms will continue mid week before drying out by the end of the week and start of the weekend. Additionally with the trough overhead, expect a cooler and drier airmass to filter overhead, supporting below normal temperatures for the later half of the week. && .AVIATION /14Z SATURDAY THROUGH WEDNESDAY/... Fog has eroded with widespread VFR conditions now in place. Scattered convection will expand northward across far western NY this afternoon. Localized brief periods of IFR or below is likely with any SHRA/TSRA, however confidence is low it will occur at a TAF site. An organized area of showers and storms may move across the Eastern Lake Ontario region tonight with additional showers and storms across western NY. IFR or below is anticipated in any activity, with MVFR conditions occurring by Sunday morning. Outlook... Sunday...MVFR/VFR becoming mainly VFR Sunday afternoon. Showers with a chance of thunderstorms Sunday morning. Sunday Night through Monday...Mainly VFR. Tuesday through Wednesday...Mainly VFR. Chance of showers/afternoon thunderstorms. && .MARINE... Light winds will continue across the Lower Great Lakes today. A warm front will begin to move back north across the region, with a chance of a few thunderstorms over Lake Erie in the afternoon. A weak wave of low pressure will cross the lower Great Lakes tonight and early Sunday. An organized area of rain and storms may impact the Lakes. Westerly winds will increase modestly Sunday afternoon behind this wave, with a light chop on the lakes. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...Air Quality Alert until midnight EDT tonight for NYZ008. MARINE...None. && $$ SYNOPSIS...JM NEAR TERM...HSK/JM SHORT TERM...EAJ LONG TERM...EAJ AVIATION...HSK/JM MARINE...Hitchcock/HSK/JM