FZUS61 KBUF 232002 GLFLO Open Lake Forecast for Lake Ontario National Weather Service Buffalo NY 402 PM EDT Sun Aug 23 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 cold front continues to sweep eastward across Lake Ontario this evening. Behind the front, a trough averaging 29.8 inches lingers over Lake Ontario through Monday. On Tuesday through Wednesday, a ridge averaging 30.1 inches builds from the western and central Great Lakes. The ridge should begin to exit eastward on Thursday and allow a warm front to sweep northeastward across Lake Ontario. On Friday, a cold front should sweep eastward across the lake and be followed by a high pressure ridge averaging 30.0 inches and building from the Upper Midwest. LOZ062-240300- Lake Ontario open waters from the Niagara River to Hamlin Beach- 402 PM EDT Sun Aug 23 2026 .TONIGHT...West winds 15 to 25 knots. A chance of waterspouts. Showers with a chance of thunderstorms early, then a chance of showers from late evening on. Waves 3 to 6 feet. .MONDAY...Southwest winds 15 to 25 knots becoming west. A chance of waterspouts. A chance of showers early, then showers likely from late morning on. Waves 3 to 6 feet building to 4 to 7 feet. Waves occasionally around 9 feet. .MONDAY NIGHT...West winds 15 to 20 knots. A chance of waterspouts. Showers likely in the evening, then showers overnight. Waves 3 to 6 feet subsiding to 2 to 4 feet. .TUESDAY...Northwest winds 15 to 20 knots becoming west 10 to 15 knots. A chance of waterspouts. Showers. Waves 2 to 4 feet subsiding to 1 to 3 feet. .TUESDAY NIGHT...West winds 10 knots or less. Waves 2 feet or less. .WEDNESDAY...Southwest winds 10 knots or less becoming south. Waves 1 foot or less. .THURSDAY...South winds 10 to 15 knots becoming west. A chance of showers and thunderstorms. Waves 2 feet or less. .FRIDAY...West winds 5 to 15 knots becoming northwest. Waves 1 to 2 feet. Winds and waves higher in and near thunderstorms. $$ LOZ063>065-240300- Lake Ontario open waters from Hamlin Beach to the Saint Lawrence River- 402 PM EDT Sun Aug 23 2026 .TONIGHT...West winds 15 to 25 knots becoming southwest. A chance of waterspouts. Showers with a chance of thunderstorms this evening, then showers after midnight. A chance of showers late. Waves 4 to 7 feet subsiding to 3 to 6 feet. Waves occasionally around 9 feet. .MONDAY...Southwest winds 15 to 20 knots. A chance of waterspouts. A chance of showers in the morning, then showers with a chance of thunderstorms in the afternoon. Waves 3 to 6 feet building to 4 to 7 feet. Waves occasionally around 9 feet. .MONDAY NIGHT...Southwest winds 15 to 20 knots becoming west. A chance of waterspouts. Showers with a chance of thunderstorms in the evening, then showers overnight. Waves 3 to 6 feet. .TUESDAY...Northwest winds 15 to 20 knots becoming west. A chance of waterspouts. Showers. Waves 3 to 5 feet subsiding to 2 to 4 feet. .TUESDAY NIGHT...West winds 5 to 15 knots. A chance of waterspouts in the evening. Waves 2 to 4 feet subsiding to 1 to 3 feet. .WEDNESDAY...Southwest winds 10 knots or less becoming south and increasing to 15 to 20 knots. Waves 1 foot or less building to 1 to 3 feet. .THURSDAY...South winds 15 to 20 knots becoming southwest 10 to 15 knots. A chance of showers and thunderstorms during the day, then showers likely with a chance of thunderstorms Thursday night. Waves 1 to 3 feet. .FRIDAY...West winds 5 to 15 knots becoming northwest. A chance of showers during the day. Waves 1 to 2 feet. Winds and waves higher in and near thunderstorms. $$ LOZ061-240300- MAFOR 2321/ ONTARIO WEST 1/2 11636 13620 12520 11536 11636. A chance of waterspouts. A chance of thunderstorms this evening. Waves 4 to 7 feet subsiding to 3 to 6 feet, and occasionally around 9 feet tonight. Waves 3 to 6 feet building to 4 to 7 feet, and occasionally around 9 feet Monday. ONTARIO EAST 1/2 12636 11626 14520 11526. A chance of waterspouts. A chance of thunderstorms this evening. Waves 4 to 7 feet subsiding to 3 to 6 feet, and occasionally around 9 feet tonight. Waves 3 to 6 feet Monday. $$