FZUS61 KBUF 310807 GLFLO Open Lake Forecast for Lake Ontario National Weather Service Buffalo NY 407 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. LOZ062-311500- Lake Ontario open waters from the Niagara River to Hamlin Beach- 407 AM EDT Tue Mar 31 2026 .TODAY...Southwest winds 10 to 15 knots becoming east 15 to 20 knots. Patchy fog early. Rain showers with a chance of thunderstorms early, then a chance of rain showers. Rain showers with a chance of thunderstorms late. Some thunderstorms may produce gusty winds late. Waves 1 to 3 feet building to 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. $$ LOZ063>065-311500- Lake Ontario open waters from Hamlin Beach to the Saint Lawrence River- 407 AM EDT Tue Mar 31 2026 .TODAY...Southwest winds 10 to 15 knots becoming northeast. Patchy fog this morning. Rain showers with a chance of thunderstorms this morning, then a chance of rain showers early this afternoon. Rain showers with a chance of thunderstorms late. Waves 2 feet or less. .TONIGHT...East winds 10 to 15 knots becoming north. Rain showers with a chance of thunderstorms in the evening, then rain showers likely with a chance of thunderstorms after midnight. A chance of rain showers late. Waves 1 to 3 feet. .WEDNESDAY...North winds 5 to 15 knots becoming northeast. A chance of rain showers. Waves 1 to 3 feet. .WEDNESDAY NIGHT...Northeast winds 5 to 15 knots increasing to 15 to 20 knots. A chance of rain showers. Waves 1 to 3 feet building to 2 to 4 feet. .THURSDAY...Northeast winds 15 to 25 knots becoming south to 30 knots. Rain showers likely. Waves 3 to 6 feet building to 4 to 7 feet. Waves occasionally around 9 feet. .FRIDAY...South winds to 30 knots becoming northwest and diminishing to 10 to 15 knots. Showers likely during the day, then a chance of showers Friday night. Waves 4 to 7 feet subsiding to 2 to 4 feet. Waves occasionally around 9 feet. .SATURDAY...Northeast winds 5 to 15 knots becoming south and increasing to 15 to 25 knots. A chance of rain showers during the day, then rain showers likely Saturday night. Waves 1 to 3 feet building to 4 to 7 feet. Waves occasionally around 9 feet. Winds and waves higher in and near thunderstorms. $$ LOZ061-311500- MAFOR 3109/ ONTARIO WEST 1/2 11406 11816 11220 13226 11116 11810. A chance of thunderstorms today and this evening. Waves 1 to 3 feet building to 2 to 4 feet today. Waves 2 to 4 feet tonight. ONTARIO EAST 1/2 11406 11716 11110 11100 12116 11816 11810. A chance of thunderstorms. Waves 2 feet or less today. Waves 1 to 3 feet tonight. $$