FXUS61 KBUF 210704 AFDBUF Area Forecast Discussion National Weather Service Buffalo NY 304 AM EDT Sun Jun 21 2026 .WHAT HAS CHANGED... Only minor changes to the forecast with this update. && .KEY MESSAGES... 1) Rain moves into the area late tonight through Monday. && .DISCUSSION... KEY MESSAGE 1...Rain moves into the area late tonight through Monday. A convectively enhanced shortwave trough over the mid Mississippi Valley this afternoon will help to re-develop a sfc low that will track east across the Ohio Valley through Monday. Additional larger scale troughing will also help develop the sfc low. The lingering vorticity and shortwave trough will track out ahead of the sfc low along a developing warm frontal boundary found along/near the NY/PA border. Guidance does vary with the location of this boundary between northern PA and closer to Lake Ontario. At the same time, an influx of synoptic moisture out ahead of the sfc low will surge into the WNY area. Showers/rain will push into the region, originally supported by the forcing from the shortwave trough and then supported additionally from the developing warm frontal boundary. The increase in moisture will help with the potential for heavier showers at times embedded within the shield of rain. Rain will taper off Monday evening into the overnight from northwest to southeast. Guidance continues to struggle with the timing and placement of the rain. As of this writing the general consensus is that showers/rain moves into far southwestern NY around or shortly after Midnight tonight and the main axis of higher rainfall amounts will be the Western Southern Tier and northeast across the Finger Lakes. Rainfall amounts in these areas of around an inch is looking likely, with lower amounts to half an inch for areas closer to Lake Ontario. Lower amounts to around a quarter of an inch is expected far north into the North Country. The track of the lingering shortwave energy and placement of the warm frontal boundary will determine how far north the rain pushes into the region, there is still the potential that the axis of heavier rain can move slightly farther north or south. && .AVIATION /07Z SUNDAY THROUGH THURSDAY/... A weak trough of low pressure will pass across western NY through the early morning hours, bringing the chance for a few scattered light showers into the Genesee Valley/Finger Lakes region through around daybreak, with any scattered shower activity then pulling east of the area as the trough moves into southcentral NY. The more notable impact will likely be lowering CIGS across the terminals south of Lake Ontario, however most CIGS across this area are forecast to be in the 5-7kft range. Exception will be across the western Southern Tier (KJHW) where low VFR/MVFR CIGS will be possible roughly in the 08Z-13Z timeframe. Mainly VFR conditions expected east of Lake Ontario, although some low VFR/MVFR CIGS may hang on across the far interior higher terrain through a portion of the morning. Low VFR/MVFR CIGS may linger across the western Southern Tier (KJHW) into the first part of the morning, otherwise mainly VFR flight conditions and dry weather are expected across the majority of the area today. Exception will again be chances for a few scattered showers and storms across the North Country and SL Valley this afternoon, which may produce localized brief reductions to IFR/MVFR within any heavier shower or storm. Otherwise, a period of low VFR CIGS (~4kft) will be possible this afternoon across interior portions of the North Country. Winds will generally be less than 10 knots through the entire TAF period. Outlook... Tonight...VFR for bulk of the night. Rain chances increase across western NY through the second half of the night, with low VFR/MVFR getting into the western Southern Tier late. Monday...MVFR/IFR with rain likely. Chance of a few thunderstorms. Tuesday and Wednesday...VFR. Thursday...Mainly VFR with a chance of showers and thunderstorms. && .MARINE... High pressure crossing the area today will result in sub SCA winds and waves. Out ahead of the high pressure, westerly winds will maintain a light chop on the lakes with winds near 10 kts. Winds will shift to the northeast and then east on Monday as an area of low pressure tracks south of the region. Winds on Monday are expected to remain around 10 kts or less. Winds are expected to remain below SCA levels through at least the middle of the new work week. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...None. MARINE...None. && $$ DISCUSSION...SW AVIATION...JM MARINE...SW