661 FZUS61 KBUF 222338 GLFLO Open Lake Forecast for Lake Ontario National Weather Service Buffalo NY 738 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 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. LOZ062-230315- Lake Ontario open waters from the Niagara River to Hamlin Beach- 738 PM EDT Sat Aug 22 2026 .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. A chance of waterspouts. Showers likely early, then a chance of showers late in the morning. Showers likely 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. A chance of waterspouts. Showers likely with a chance of thunderstorms in the evening, then showers overnight. Waves 4 to 6 feet. .MONDAY...Southwest winds 15 to 25 knots becoming west. A chance of waterspouts. Showers. Waves 5 to 8 feet. Waves occasionally around 10 feet. .MONDAY NIGHT...West winds 15 to 20 knots. A chance of waterspouts. Showers likely in the evening, then a chance of showers overnight. Waves 4 to 7 feet subsiding to 3 to 6 feet. Waves occasionally around 9 feet. .TUESDAY...West winds 15 to 20 knots diminishing to 10 knots or less. A chance of waterspouts during the day. Showers likely during the day. 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. .THURSDAY...South winds 5 to 10 knots becoming southwest. A chance of showers and thunderstorms. Waves 1 foot or less. Winds and waves higher in and near thunderstorms. $$ LOZ063>065-230315- Lake Ontario open waters from Hamlin Beach to the Saint Lawrence River- 738 PM EDT Sat Aug 22 2026 .TONIGHT...Southeast winds 5 to 10 knots becoming south and increasing to 15 to 25 knots after midnight. Showers with a chance of thunderstorms. Waves 1 to 3 feet building to 3 to 5 feet. .SUNDAY...South winds 15 to 25 knots becoming west. A chance of waterspouts. Showers with a chance of thunderstorms in the morning, then a chance of showers and thunderstorms early in the afternoon. Showers with a chance of thunderstorms late. Waves 3 to 5 feet building to 3 to 6 feet. .SUNDAY NIGHT...West winds 15 to 20 knots becoming southwest. A chance of waterspouts. Showers with a chance of thunderstorms in the evening, then showers overnight. Waves 3 to 6 feet building to 4 to 7 feet. Waves occasionally around 9 feet. .MONDAY...Southwest winds 15 to 25 knots. A chance of waterspouts. Showers. Waves 5 to 8 feet building to 6 to 9 feet. Waves occasionally around 11 feet. .MONDAY NIGHT...West winds 15 to 20 knots. A chance of waterspouts. Showers. Waves 5 to 9 feet subsiding to 3 to 6 feet. Waves occasionally around 11 feet. .TUESDAY...West winds 15 to 20 knots diminishing to 5 to 15 knots. A chance of waterspouts. Showers during the day, then a chance of showers Tuesday night. Waves 3 to 6 feet subsiding to 1 to 3 feet. .WEDNESDAY...West winds 5 to 15 knots becoming south. Waves 2 feet or less. .THURSDAY...South winds 5 to 15 knots. A chance of showers during the day, then showers likely Thursday night. Waves 2 feet or less. Winds and waves higher in and near thunderstorms. $$ LOZ061-230315- MAFOR 2221/ ONTARIO WEST 1/2 11200 11306 12416 11510 13620. A chance of waterspouts Sunday. A chance of thunderstorms tonight and Sunday afternoon. Waves 1 to 3 feet tonight. Waves 1 to 3 feet building to 3 to 6 feet Sunday. ONTARIO EAST 1/2 11300 11310 12426 11436 12520 11620. A chance of waterspouts Sunday. A chance of thunderstorms tonight and Sunday morning. Waves 1 to 3 feet building to 3 to 5 feet tonight. Waves 3 to 5 feet building to 3 to 6 feet Sunday. $$ AR  687 FZUS61 KBUF 222339 GLFSL Forecast for the Saint Lawrence River including the Thousand Islands Region National Weather Service Buffalo NY 739 PM EDT Sat Aug 22 2026 SLZ022-024-230315- Saint Lawrence River from Cape Vincent to Saint Regis 739 PM EDT Sat Aug 22 2026 .TONIGHT...East winds 10 knots or less becoming southeast 10 to 15 knots. A chance of showers and thunderstorms after midnight. Showers likely with a chance of thunderstorms late. .SUNDAY...Southeast winds 10 to 15 knots becoming southwest. Showers with a chance of thunderstorms. .SUNDAY NIGHT...Southwest winds 10 to 15 knots. A chance of showers in the evening, then showers overnight. .MONDAY...Southwest winds 5 to 15 knots. Showers in the morning, then showers with a chance of thunderstorms in the afternoon. .MONDAY NIGHT...Southwest winds 5 to 10 knots. Showers likely in the evening, then a chance of showers overnight. .TUESDAY...West winds 5 to 10 knots becoming light and variable. A chance of showers and thunderstorms. .WEDNESDAY...Southwest winds less than 10 knots becoming south. Partly cloudy. .THURSDAY...South winds 10 knots or less. A chance of showers during the day, then showers likely Thursday night. Winds and waves higher in and near thunderstorms. $$ AR