Area Forecast Discussion
Issued by NWS Buffalo, NY
Issued by NWS Buffalo, NY
399 FXUS61 KBUF 280559 AFDBUF Area Forecast Discussion National Weather Service Buffalo NY 159 AM EDT Tue Jul 28 2026 .WHAT HAS CHANGED... Increased rain amounts across the eastern Lake Ontario region Tuesday night through Wednesday. && .KEY MESSAGES... 1) Multiple rounds of showers and thunderstorms are expected tonight through Wednesday, with heavy downpours and localized gusty winds. 2) Chances for showers and thunderstorms linger into Thursday, with drier conditions for the end of the work week. && .DISCUSSION... Key Message 1...Multiple rounds of showers and thunderstorms are expected tonight through Wednesday, with heavy downpours and localized gusty winds. Current surface analysis depicts a low over southeastern Wisconsin/northwestern Illinois early this morning, supporting a warm front to extend southward from it and a cold front to extend west and northwest across the Wisconsin/Illinois border. This low will track across the central Great Lakes this morning before lifting east-northeast across New York state today. Ahead of the low an area of increasing mid-level winds, steep mid-level lapse rates and high PWAT values will continue to work its way across far WNY early this morning. 0-6km wind shear will increase to between 20 and 30 knots while remain less than 20 knots across the Genesee Valley, limiting the severe thunderstorm potential to far western New York. This being said, upstream convection, is beginning to work its way east across the region this morning, where numerous showers and thunderstorms will continue to move across the region through Tuesday morning. Conditions are marginally favorable for an isolated severe thunderstorm across far western New York early this morning, with gusty winds will remain the favorable hazard. Additionally, due to the larger PWAT values, expect heavy rain with any stronger storm. As mentioned previously, the surface low will track across New York state today, before becoming nearly stationary across north-central New York Tuesday night through Wednesday. While showers will taper off across far western New York later this morning, diurnal heating within a very soggy environment will support additional showers and thunderstorms this afternoon. Meanwhile to the east, a low-level jet will wrap around the surface low, supporting a few strong thunderstorms where heavy rainfall may lead to localized flooding across areas of the Finger Lakes eastward into north-central New York through this evening. As the surface low settles across eastern New York tonight, wrap around moisture will support continued chances for showers across the entirety of the forecast area. There is a Marginal Risk of Excessive Rainfall for portions of western and north-central NY through Wednesday. Key Message 2...Chances for showers and thunderstorms are expected to linger into Thursday, with drier conditions for the end of the work week. An anomalous strong area of surface low pressure will gradually slide east off the coast of southern New England Thursday. This will support the plume of moisture to pull east, however some diurnally driven convection will be possible for areas inland from the lakes. Otherwise, expect cooler temperatures with highs in the 70s. High pressure will then move in across the eastern Great Lakes for for the end of the work week supporting dry and seasonal weather. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... At the surface, a weak high pressure ridge exits generally E`ward and a cold front should drift SE`ward across our region between ~12Z and ~19Z/Tues. In addition, a low pressure center along the front should wobble ESE`ward from southeastern Lower MI to east-central PA and strengthen slightly. Behind the front, a trough lingers over western and central NY through 06Z/Wed. Our regional surface winds trend S`erly to SW`erly around 5 knots ahead of the cold front. Behind the front, surface winds are expected to be NE`erly to NW`erly around 5 to 10 knots. Scattered showers and thunderstorms are expected to persist generally E`ward along and ahead of the cold front. Some of these storms may produce brief and erratic surface wind gusts up to 30 to 50 knots. Conditions are expected to vary from VFR outside this convection to MVFR to LIFR in showers/storms with periods of torrential rainfall. Behind the cold front, scattered to widespread showers, steady to heavy at times, and widespread low ceilings in the MVFR to IFR range are expected as primarily NW`erly to N`erly and moist low-level upslope flow, and wrap-around rain on the backside of the low pressure system, impact our region. Periodic mist and MVFR to IFR visibility are expected with these showers. Isolated thunderstorms are possible behind the surface cold front. Outlook... Tuesday night through Saturday...Periodic showers and thunderstorms with non-VFR are expected, especially Tuesday night through Wednesday evening. && .MARINE... Tonight and Tuesday a broad wave of low pressure will settle southeastward from the Upper Great Lakes into central/eastern New York...with the low then slowly drifting to the mid-Atlantic coastline Tuesday night and Wednesday. As this occurs a light to modest southerly flow out ahead of the low tonight will transition to an increasingly brisk northerly to northeasterly flow Tuesday and Tuesday night following the passage of the low. While the finer details of this transition have yet to be ironed out...this will likely eventually lead to a period of SCA-worthy conditions along the southern shores of both lakes from sometime late Tuesday/Tuesday evening through Wednesday...before winds lighten and turn more westerly Thursday/Friday and allow for a commensurate decrease in wave action. Out ahead of the approaching low...scattered showers and thunderstorms will also be possible across eastern Lake Erie and western Lake Ontario into this evening...with more widespread showers and scattered thunderstorms then expected later tonight and Tuesday as the low crosses our region. Any storms could produce locally higher winds and waves, with this potential greatest across Lake Erie tonight. && .MARINE... Tonight and Tuesday a broad wave of low pressure will settle southeastward from the Upper Great Lakes into central/eastern New York...with the low then slowly drifting to the mid-Atlantic coastline Tuesday night and Wednesday. As this occurs a light to modest southerly flow out ahead of the low tonight will transition to an increasingly brisk northerly to northeasterly flow Tuesday and Tuesday night following the passage of the low. While the finer details of this transition have yet to be ironed out...this will likely eventually lead to a period of SCA-worthy conditions along the southern shores of both lakes from sometime late Tuesday/Tuesday evening through Wednesday...before winds lighten and turn more westerly Thursday/Friday and allow for a commensurate decrease in wave action. Out ahead of the approaching low...scattered showers and thunderstorms will also be possible across eastern Lake Erie and western Lake Ontario into this evening...with more widespread showers and scattered thunderstorms then expected later tonight and Tuesday as the low crosses our region. Any storms could produce locally higher winds and waves, with this potential greatest across Lake Erie tonight. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...None. MARINE...None. && $$ DISCUSSION...EAJ AVIATION...Jaszka MARINE...JJR/TMA