FZUS61 KBUF 042009 GLFLO Open Lake Forecast for Lake Ontario National Weather Service Buffalo NY 409 PM EDT Sat Apr 4 2026 For waters beyond five nautical miles of shore on Lake Ontario Waves are the significant wave height - the average of the highest 1/3 of the wave spectrum. Occasional wave height is the average of the highest 1/10 of the wave spectrum. .SYNOPSIS...A 29.4 inch surface low will track through the central Great Lakes this afternoon and evening before tracking into Quebec tonight and Sunday. With its track, a strong cold front will pass across the lake early tonight, with a secondary cold front then following Sunday night and Monday. A 30.5 inch high will then build across the Great Lakes Tuesday and Tuesday night, before sliding east and off the New England coast Wednesday. LOZ062-050300- Lake Ontario open waters from the Niagara River to Hamlin Beach- 409 PM EDT Sat Apr 4 2026 .TONIGHT...East winds 15 to 25 knots becoming southwest 15 to 20 knots. A chance of showers early, then showers with a chance of thunderstorms. Showers late. Patchy fog after midnight. Some thunderstorms may produce gusty winds. Waves 5 to 8 feet subsiding to 3 to 6 feet. Waves occasionally around 10 feet. .SUNDAY...West winds 15 to 25 knots. Waves 3 to 6 feet building to 5 to 8 feet. Waves occasionally around 10 feet. .SUNDAY NIGHT...West winds 15 to 25 knots. Waves 5 to 8 feet subsiding to 3 to 6 feet. Waves occasionally around 10 feet. .MONDAY...West winds 15 to 20 knots diminishing to 10 to 15 knots. A chance of rain and snow showers in the afternoon. Waves 3 to 5 feet subsiding to 1 to 3 feet. .MONDAY NIGHT...West winds 10 to 15 knots becoming northwest 15 to 20 knots. Snow and rain showers. Waves 1 to 3 feet building to 3 to 5 feet. .TUESDAY...Northwest winds 15 to 25 knots becoming west and diminishing to 5 to 10 knots. Snow showers during the day. Waves 3 to 6 feet subsiding to 1 to 3 feet. .WEDNESDAY...South winds 5 to 10 knots increasing to 15 to 25 knots. Waves 1 foot or less building to 3 to 6 feet. .THURSDAY...Southwest winds 15 to 25 knots becoming west. A chance of showers. Waves 4 to 7 feet subsiding to 3 to 6 feet. Waves occasionally around 9 feet. Winds and waves higher in and near thunderstorms. $$ LOZ063>065-050300- Lake Ontario open waters from Hamlin Beach to the Saint Lawrence River- 409 PM EDT Sat Apr 4 2026 .TONIGHT...East winds 15 to 25 knots becoming southwest. A chance of showers this evening, then showers after midnight. Patchy fog after midnight. Waves 3 to 6 feet building to 5 to 8 feet. Waves occasionally around 10 feet. .SUNDAY...West winds 15 to 25 knots increasing to 30 knots. Rain showers likely early. A chance of rain showers late. Waves 3 to 6 feet building to 5 to 9 feet. Waves occasionally around 11 feet. .SUNDAY NIGHT...West winds 15 to 25 knots. A chance of rain showers overnight. Waves 6 to 9 feet. Waves occasionally around 11 feet. .MONDAY...West winds 15 to 20 knots diminishing to 10 to 15 knots. A chance of snow showers. Waves 4 to 7 feet subsiding to 1 to 3 feet. Waves occasionally around 9 feet. .MONDAY NIGHT...West winds 10 to 15 knots becoming north 15 to 20 knots. Snow showers with rain showers likely. Waves 1 to 3 feet building to 3 to 5 feet. .TUESDAY...North winds 15 to 25 knots becoming northwest and diminishing to 10 to 15 knots. Snow showers during the day. Waves 3 to 6 feet subsiding to 2 to 4 feet. .WEDNESDAY...Southwest winds 5 to 10 knots becoming south and increasing to 30 knots. Waves 1 to 3 feet building to 5 to 8 feet. Waves occasionally around 10 feet. .THURSDAY...South winds to 30 knots becoming southwest 15 to 25 knots. A chance of rain showers. Waves 5 to 8 feet subsiding to 3 to 6 feet. Waves occasionally around 10 feet. Winds and waves higher in and near thunderstorms. $$ LOZ061-050300- MAFOR 0421/ ONTARIO WEST 1/2 11230 11320 12526 12620 12630. A chance of thunderstorms tonight. Waves 5 to 8 feet subsiding to 3 to 6 feet, and occasionally around 10 feet tonight. Waves 3 to 6 feet building to 5 to 8 feet, and occasionally around 10 feet Sunday. ONTARIO EAST 1/2 11220 11330 11446 11546 11526 11620 12630. Waves 3 to 6 feet building to 5 to 8 feet, and occasionally around 10 feet tonight. Waves 3 to 6 feet building to 5 to 9 feet, and occasionally around 11 feet Sunday. $$