FZUS61 KBUF 311411 GLFLO Open Lake Forecast for Lake Ontario National Weather Service Buffalo NY 1010 AM EDT Tue Mar 31 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 frontal zone will stall near the south shore of the lake today. A 29.6 inch low will move across southern Ontario province this evening before reaching the Canadian Maritimes Wednesday, with a trailing cold front moving south across the lake tonight. A 30.6 inch high will then build east across Ontario and Quebec Wednesday through Thursday. A 29.6 inch low is then forecast to move into the central Great Lakes Thursday night before reaching southern Quebec late Friday. LOZ062-312100- Lake Ontario open waters from the Niagara River to Hamlin Beach- 1010 AM EDT Tue Mar 31 2026 .REST OF TODAY...East winds 15 to 20 knots. Rain showers likely with a chance of thunderstorms late this morning, then a chance of rain showers early this afternoon. Rain showers with a chance of thunderstorms late. Some thunderstorms may produce gusty winds late. Waves 2 to 4 feet. .TONIGHT...East winds 15 to 20 knots becoming north 10 to 15 knots. Rain showers with a chance of thunderstorms in the evening, then rain showers likely after midnight. A chance of rain showers late. Some thunderstorms may produce gusty winds early. Waves 2 to 4 feet. .WEDNESDAY...North winds 5 to 15 knots becoming northeast. A chance of rain showers. Waves 1 to 3 feet. .WEDNESDAY NIGHT...East winds 5 to 15 knots becoming northeast 15 to 20 knots. A chance of rain showers. Waves 2 feet or less building to 3 to 5 feet. .THURSDAY...East winds 15 to 25 knots becoming south. Rain showers likely. Waves 4 to 7 feet subsiding to 3 to 5 feet. Waves occasionally around 9 feet. .FRIDAY...Southwest winds 15 to 25 knots becoming north and diminishing to 10 to 15 knots. Showers likely during the day, then a chance of showers Friday night. Waves 3 to 6 feet subsiding to 2 to 4 feet. .SATURDAY...Northeast winds 10 to 15 knots becoming southwest 15 to 20 knots. A chance of showers during the day, then showers likely Saturday night. Waves 1 to 3 feet building to 3 to 5 feet. Winds and waves higher in and near thunderstorms. $$ LOZ063>065-312100- Lake Ontario open waters from Hamlin Beach to the Saint Lawrence River- 1010 AM EDT Tue Mar 31 2026 .REST OF TODAY...North winds 10 to 15 knots becoming northeast. Rain showers with a chance of thunderstorms late this morning, then a chance of rain showers early this afternoon. Rain showers with a chance of thunderstorms late. Some thunderstorms may produce gusty winds late. Waves 1 to 2 feet. .TONIGHT...East winds 10 to 15 knots becoming north. Rain showers with a chance of thunderstorms in the evening, then rain showers likely with a chance of thunderstorms after midnight. A chance of rain showers late. Some thunderstorms may produce gusty winds early. Waves 1 to 3 feet. .WEDNESDAY...North winds 5 to 15 knots becoming northeast. A chance of rain showers. Waves 1 to 3 feet. .WEDNESDAY NIGHT...Northeast winds 5 to 15 knots increasing to 15 to 20 knots. A chance of rain showers. Waves 1 to 3 feet building to 2 to 4 feet. .THURSDAY...Northeast winds 15 to 25 knots becoming south to 30 knots. Rain showers likely. Waves 3 to 6 feet building to 4 to 7 feet. Waves occasionally around 9 feet. .FRIDAY...South winds to 30 knots becoming northwest and diminishing to 10 to 15 knots. Showers likely during the day, then a chance of showers Friday night. Waves 4 to 7 feet subsiding to 2 to 4 feet. Waves occasionally around 9 feet. .SATURDAY...Northeast winds 5 to 15 knots becoming south and increasing to 15 to 25 knots. A chance of rain showers during the day, then rain showers likely Saturday night. Waves 1 to 3 feet building to 4 to 7 feet. Waves occasionally around 9 feet. Winds and waves higher in and near thunderstorms. $$ LOZ061-312100- MAFOR 3115/ ONTARIO WEST 1/2 11220 13226 11116 12810 11800. A chance of thunderstorms this afternoon and evening. Waves 2 to 4 feet this afternoon and tonight. Waves 1 to 3 feet Wednesday morning. ONTARIO EAST 1/2 12110 12116 11816 13810. A chance of thunderstorms this afternoon and tonight. Waves 1 to 3 feet. $$