Area Forecast Discussion
Issued by NWS Buffalo, NY
Issued by NWS Buffalo, NY
743 FXUS61 KBUF 090132 AFDBUF Area Forecast Discussion National Weather Service Buffalo NY 932 PM EDT Tue Sep 8 2026 .WHAT HAS CHANGED... Adjusted PoP`s upward, overall, and made minor edits to QPF from about daybreak through early evening on Wednesday to account for latest trends in obs, including upstream obs, and NWP model guidance. && .KEY MESSAGES... 1) A cold front will cross the eastern Great Lakes Wednesday through Wednesday night, producing showers and scattered thunderstorms. A few storms may be severe with isolated damaging wind gusts the primary hazard. 2) A few showers may linger Thursday mainly across the Southern Tier, with dry weather returning Friday through Saturday. && .DISCUSSION... KEY MESSAGE 1...A cold front will cross the eastern Great Lakes Wednesday through Wednesday night, producing showers and scattered thunderstorms. A few storms may be severe with isolated damaging wind gusts the primary hazard. Increasingly moist isentropic ascent aloft, ahead of the next low pressure system, will allow widespread cloud cover, initially in the mid/upper-levels, to lower and thicken into widespread low-level clouds generally from west to east between about daybreak and midday Wednesday. Periodic and isolated to scattered showers and thunderstorms should blossom and overspread our region generally from west to east beginning around daybreak and continuing through Wednesday afternoon as weak to moderate CAPE, including elevated CAPE, is released by the following: the isentropic ascent with a moisture tap to the Gulf; low-level convergence/moist ascent along surface trough axes accompanying shortwave troughs embedded in W`erly mid/upper-level flow; downshear outflow boundaries interacting favorably with ambient low-level vertical wind shear amidst primarily moderate to strong deep-layer bulk shear. The main area of showers and scattered thunderstorms will arrive late Wednesday afternoon through late evening as a broken band of showers and scattered thunderstorms cross the region. A sharp mid level trough will cross Ontario and Quebec, with the southern extent of height falls spreading east across the Great Lakes and providing some large scale forcing for ascent. The main focus for convection will be a pre-frontal trough that is forecast to reach the eastern Great Lakes by early evening. The low pressure system will capture a narrow plume of deep moisture, with PWAT values briefly exceeding 2 inches late Wednesday just ahead of the pre-frontal trough. Any thunderstorms will produce brief downpours, but fast storm motion will likely keep the flood risk low. Strong deep-layer bulk shear will overspread the area Wednesday, with boundary layer flow increasing to 40+ knots. Poor mid-level lapse rates will keep instability somewhat limited, but the latest NWP model guidance suggests that sufficient instability may develop to support some severe thunderstorm risk from late afternoon through mid to late evening. The largely unidirectional wind profiles will support localized damaging wind gusts as the primary severe convective weather hazard. Showers and scattered thunderstorms will taper off from northwest to southeast overnight. KEY MESSAGE 2...A few showers may linger Thursday mainly across the Southern Tier, with dry weather returning Friday through Saturday. The cold front will stall across Ohio and PA Thursday as a weak baroclinic wave moves east down the boundary. This wave will produce an area of organized rain to our south across Ohio and PA. Most of this will miss our region, although a few showers may develop across the Southern Tier. Otherwise, the rest of the area will be mainly dry Thursday with a good deal of cloud cover north of the frontal wave. The front will then accelerate southeast and into the Mid Atlantic Thursday night as high pressure builds into the central Great Lakes. Dry weather and sunshine will return Friday through Saturday as high pressure drifts from the Great Lakes east to New England. The next chance of showers may arrive by Sunday as the next mid level trough and cold front move into the Great Lakes. && .AVIATION /01Z WEDNESDAY THROUGH SUNDAY/... W`erly to NW`erly flow aloft and embedded disturbances affect Western and Central NY through 00Z/Thurs. Simultaneously and at the surface, a high pressure ridge exits E`ward. Initially light and variable surface winds are expected to become S`erly to SW`erly around 5 to 15 knots Wed morning and then persist through 00Z/Thurs. Diurnal convective mixing of the boundary layer tapping into stronger flow aloft should allow these winds to gust up to 20 to 25 knots at times Wed afternoon through early evening. Dry weather and widespread VFR are expected for the time being. Widespread ceilings, initially in the mid/upper-levels, are expected to lower to near 4kft to 6kft AGL and generally from west to east between ~10Z/Wed and ~15Z/Wed. Periodic and scattered showers and thunderstorms associated with the aforementioned disturbances should blossom and overspread our region generally from west to east between ~11Z/Wed and ~16Z/Wed. Periodic/scattered showers/thunderstorms should then persist through 00Z/Thurs. Brief MVFR to LIFR and downpours are expected with showers and thunderstorms. Some storms may produce brief/erratic surface wind gusts up to 30 to 50 knots Wed afternoon through 00Z/Thurs. Outlook... Wednesday Night...Widespread MVFR or lower ceilings and isolated to scattered showers/thunderstorms expected. Thursday...MVFR or lower ceilings early, improving to VFR. A few showers are possible across the Western Southern Tier. Friday through Saturday...Mainly VFR and dry weather expected. Sunday...Mainly VFR expected, but scattered showers are possible. && .MARINE... Low pressure will track east across Hudson Bay Wednesday before reaching northern Quebec Thursday, with a trailing cold front crossing the lower Great Lakes Wednesday night. A belt of enhanced winds will develop south of the low, with southerly winds increasing on the lower Great Lakes tonight, then increasing further and veering to the southwest Wednesday. Winds and waves will approach low end Small Craft Advisory criteria by Wednesday afternoon on both lakes, with winds peaking Wednesday evening. Elevated winds and waves will likely continue through Thursday evening on Lake Ontario. High pressure will build east across the Great Lakes Thursday night through Friday with subsiding winds and waves. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...None. MARINE...None. && $$ DISCUSSION...Hitchcock/Jaszka AVIATION...Jaszka MARINE...Hitchcock