FZUS61 KBUF 050212 GLFLO Open Lake Forecast for Lake Ontario National Weather Service Buffalo NY 1012 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 29.7 inch surface low across the central Great Lakes this evening will track into Quebec tonight and Sunday. Meanwhile, a strong cold front, associated with the said surface low, will pass across the lake 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. A 29.6 inch surface low will then track northeast across the Ontario province, dragging a pair of fronts, warm then cold, across the lake Thursday. LOZ062-050900- Lake Ontario open waters from the Niagara River to Hamlin Beach- 1012 PM EDT Sat Apr 4 2026 .REST OF TONIGHT...South winds 10 to 15 knots becoming southwest 15 to 20 knots. Showers with a chance of thunderstorms, then showers late. Patchy fog after midnight. Some thunderstorms may produce gusty winds. Waves 3 to 5 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. $$ LOZ063>065-050900- Lake Ontario open waters from Hamlin Beach to the Saint Lawrence River- 1012 PM EDT Sat Apr 4 2026 .REST OF TONIGHT...South winds to 30 knots becoming southwest 15 to 25 knots. A chance of showers late this evening, then showers after midnight. Patchy fog after midnight. Waves 3 to 6 feet building to 5 to 8 feet. Waves occasionally around 10 feet. .SUNDAY...West winds 15 to 25 knots increasing to 30 knots. Rain showers likely early. A chance of rain showers late. Waves 3 to 6 feet building to 5 to 9 feet. Waves occasionally around 11 feet. .SUNDAY NIGHT...West winds 15 to 25 knots. A chance of rain showers overnight. Waves 6 to 9 feet. Waves occasionally around 11 feet. .MONDAY...West winds 15 to 20 knots diminishing to 10 to 15 knots. A chance of snow showers. Waves 4 to 7 feet subsiding to 1 to 3 feet. Waves occasionally around 9 feet. .MONDAY NIGHT...West winds 10 to 15 knots becoming north 15 to 20 knots. Snow showers with rain showers likely. Waves 1 to 3 feet building to 3 to 5 feet. .TUESDAY...North winds 15 to 25 knots becoming northwest and diminishing to 10 to 15 knots. Snow showers during the day. Waves 3 to 6 feet subsiding to 2 to 4 feet. .WEDNESDAY...Southwest winds 5 to 10 knots becoming south and increasing to 30 knots. Waves 1 to 3 feet building to 5 to 8 feet. Waves occasionally around 10 feet. .THURSDAY...South winds to 30 knots becoming southwest 15 to 25 knots. A chance of rain showers. Waves 5 to 8 feet subsiding to 3 to 6 feet. Waves occasionally around 10 feet. Winds and waves higher in and near thunderstorms. $$ LOZ061-050900- MAFOR 0503/ ONTARIO WEST 1/2 12526 12620 14630. A chance of thunderstorms overnight. Waves 2 to 4 feet overnight. Waves 3 to 6 feet building to 5 to 8 feet, and occasionally around 10 feet Sunday. Waves 5 to 8 feet, and occasionally around 10 feet Sunday evening. ONTARIO EAST 1/2 11446 11546 11526 11620 14630. Waves 3 to 6 feet building to 5 to 8 feet, and occasionally around 10 feet overnight. Waves 3 to 6 feet building to 5 to 9 feet, and occasionally around 11 feet Sunday. Waves 6 to 9 feet, and occasionally around 11 feet Sunday evening. $$