958 FZUS61 KBUF 221727 GLFLO Open Lake Forecast for Lake Ontario National Weather Service Buffalo NY 127 PM EDT Sat Aug 22 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 high pressure ridge averaging 30.1 inches exits toward the Canadian Maritimes today. Elsewhere, a 29.6 inch low should wobble northeastward from the central Great Lakes to southwestern Quebec through Monday. In response to the low's track, a warm front drifts northeastward across Lake Ontario tonight and then a cold front sweeps eastward across the lake overnight tonight through Sunday. 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. LOZ062-222115- Lake Ontario open waters from the Niagara River to Hamlin Beach- 127 PM EDT Sat Aug 22 2026 ...SEVERE THUNDERSTORM WATCH 614 IN EFFECT UNTIL 9 PM EDT THIS EVENING... .THIS AFTERNOON...East winds 10 knots or less. A chance of showers and thunderstorms late. Waves around 1 foot. .TONIGHT...East winds 5 to 15 knots becoming south. Showers with a chance of thunderstorms. Waves 1 to 2 feet. .SUNDAY...Southwest winds 15 to 20 knots becoming west. Showers likely in the morning, then showers with a chance of thunderstorms in the afternoon. Waves 1 to 3 feet building to 3 to 6 feet. .SUNDAY NIGHT...West winds 15 to 20 knots. Showers likely with a chance of thunderstorms in the evening, then a chance of showers overnight. Waves 4 to 6 feet. .MONDAY...Southwest winds 15 to 25 knots becoming west. Showers during the day, then showers likely Monday night. Waves 5 to 8 feet subsiding to 3 to 5 feet. Waves occasionally around 10 feet. .TUESDAY...West winds 15 to 20 knots diminishing to 10 knots or less. Waves 2 to 4 feet subsiding to 1 foot or less. .WEDNESDAY...Southwest winds 10 knots or less becoming south. Waves 1 foot or less. Winds and waves higher in and near thunderstorms. $$ LOZ063>065-222115- Lake Ontario open waters from Hamlin Beach to the Saint Lawrence River- 127 PM EDT Sat Aug 22 2026 .THIS AFTERNOON...Southeast winds 5 to 10 knots. Waves 2 feet or less. .TONIGHT...Southeast winds 5 to 10 knots becoming south and increasing to 15 to 25 knots after midnight. Showers with a chance of thunderstorms. Waves 1 to 3 feet building to 3 to 5 feet. .SUNDAY...South winds 15 to 25 knots becoming west. Showers with a chance of thunderstorms. Waves 3 to 5 feet building to 3 to 6 feet. .SUNDAY NIGHT...West winds 15 to 20 knots becoming southwest. Showers likely with a chance of thunderstorms in the evening, then showers overnight. Waves 3 to 6 feet building to 4 to 7 feet. Waves occasionally around 9 feet. .MONDAY...Southwest winds 15 to 25 knots becoming west. Showers. Waves 4 to 7 feet building to 6 to 9 feet, then subsiding to 4 to 7 feet. Waves occasionally around 11 feet. .TUESDAY...West winds 15 to 20 knots diminishing to 5 to 15 knots. A chance of showers during the day. Waves 3 to 6 feet subsiding to 1 to 3 feet. .WEDNESDAY...West winds 5 to 15 knots becoming south. Waves 2 feet or less. Winds and waves higher in and near thunderstorms. $$ LOZ061-222115- MAFOR 2215/ ONTARIO WEST 1/2...SEVERE THUNDERSTORM WATCH IN EFFECT...11300 12200 11306 12416 11510 11620. A chance of thunderstorms tonight. Waves 1 to 3 feet this afternoon and tonight. Waves 1 to 3 feet building to 2 to 4 feet Sunday morning. ONTARIO EAST 1/2 11310 12300 11310 12426 11436 11520. A chance of thunderstorms tonight and Sunday morning. Waves 2 feet or less this afternoon. Waves 1 to 3 feet building to 3 to 5 feet tonight. Waves 3 to 5 feet subsiding to 2 to 4 feet Sunday morning. $$ SGK