FZUS61 KBUF 230802 GLFLO Open Lake Forecast for Lake Ontario National Weather Service Buffalo NY 402 AM 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 29.6 inch low northwest of the Lake this morning will slowly wobble northeastward across southern Quebec through Monday. In response to the low's track a cold front sweeps eastward across the lake through midday today. Behind the cold 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. LOZ062-231500- Lake Ontario open waters from the Niagara River to Hamlin Beach- 402 AM EDT Sun Aug 23 2026 .TODAY...Southwest winds 15 to 25 knots becoming west. A chance of waterspouts. A chance of showers this morning, then showers with a chance of thunderstorms this afternoon. Waves 1 to 3 feet building to 3 to 6 feet. .TONIGHT...West winds 15 to 25 knots. A chance of waterspouts. Showers likely with a chance of thunderstorms early, then a chance of showers. Showers likely late. Waves 4 to 6 feet. .MONDAY...Southwest winds to 30 knots becoming west. A chance of waterspouts. Showers. Waves 4 to 7 feet building to 6 to 9 feet. Waves occasionally around 11 feet. .MONDAY NIGHT...West winds 15 to 25 knots. A chance of waterspouts. Showers likely in the evening, then a chance of showers overnight. Waves 5 to 8 feet subsiding to 3 to 6 feet. Waves occasionally around 10 feet. .TUESDAY...West winds 15 to 20 knots becoming northwest and diminishing to less than 10 knots. A chance of waterspouts during the day. A chance of showers during the day. Waves 3 to 5 feet subsiding to 1 foot or less. .WEDNESDAY...Southwest winds 10 knots or less becoming south. Waves 1 foot or less. .THURSDAY...South winds 5 to 10 knots becoming southwest. A chance of showers and thunderstorms. Waves 2 feet or less. Winds and waves higher in and near thunderstorms. $$ LOZ063>065-231500- Lake Ontario open waters from Hamlin Beach to the Saint Lawrence River- 402 AM EDT Sun Aug 23 2026 .TODAY...South winds 15 to 20 knots becoming west and increasing to 30 knots. A chance of waterspouts. Showers with a chance of thunderstorms this morning, then a chance of showers and thunderstorms early this afternoon. Showers with a chance of thunderstorms late. Waves 2 to 4 feet building to 4 to 7 feet. Waves occasionally around 9 feet. .TONIGHT...West winds 15 to 25 knots becoming southwest. A chance of waterspouts. Showers with a chance of thunderstorms in the evening, then showers after midnight. Waves 4 to 7 feet. Waves occasionally around 9 feet. .MONDAY...Southwest winds 15 to 25 knots increasing to 30 knots. A chance of waterspouts. Showers in the morning, then showers with a chance of thunderstorms in the afternoon. Waves 3 to 6 feet building to 6 to 9 feet. Waves occasionally around 11 feet. .MONDAY NIGHT...Southwest winds 15 to 25 knots becoming west. A chance of waterspouts. Showers with a chance of thunderstorms in the evening, then showers overnight. Waves 5 to 9 feet subsiding to 4 to 7 feet. Waves occasionally around 11 feet. .TUESDAY...West winds 15 to 20 knots becoming northwest 5 to 15 knots. A chance of waterspouts during the day. Showers during the day. Waves 3 to 6 feet subsiding to 1 to 3 feet. .WEDNESDAY...West winds 5 to 15 knots becoming southeast. Waves 2 feet or less. .THURSDAY...South winds 15 to 20 knots becoming southwest 10 to 15 knots. A chance ofshowers and thunderstorms during the day, then showers likely with a chance of thunderstorms Thursday night. Waves 1 to 3 feet. Winds and waves higher in and near thunderstorms. $$ LOZ061-231500- MAFOR 2309/ ONTARIO WEST 1/2 11510 12620 12636 13620. A chance of waterspouts. A chance of thunderstorms this afternoon and evening. Waves 1 to 3 feet building to 4 to 7 feet, and occasionally around 9 feet today. Waves 4 to 7 feet, and occasionally around 9 feet tonight. ONTARIO EAST 1/2 11426 12520 11620 12636 11526 11520. A chance of waterspouts. A chance of thunderstorms today and this evening. Waves 2 to 4 feet building to 4 to 7 feet, and occasionally around 9 feet today. Waves 4 to 7 feet, and occasionally around 9 feet tonight. $$