128 FZUS61 KBUF 161637 GLFLO Open Lake Forecast for Lake Ontario National Weather Service Buffalo NY 1236 PM EDT Thu Apr 16 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 will move across the central Great Lakes today before reaching southern Quebec tonight, then drift off the New England coast by Friday night. A 30.0 inch high is then forecast to build from the central Great Lakes Friday to the lower Great Lakes Saturday morning, then off the east coast Saturday night. A 29.3 inch surface low to the north of Lake Superior Saturday will deepen to 28.9 inches by Sunday, with a trailing cold front crossing the Lake Saturday night. A 30.4 inch surface high will push from the Plains to the Upper Ohio Valley from Sunday through Monday. The high is expected to move off the Mid-Atlantic coast Tuesday. LOZ062-162100- Lake Ontario open waters from the Niagara River to Hamlin Beach- 1236 PM EDT Thu Apr 16 2026 .THIS AFTERNOON...Southwest winds 15 to 20 knots. Showers with a chance of thunderstorms. Some thunderstorms may produce gusty winds. Waves 1 to 3 feet building to 2 to 4 feet. .TONIGHT...West winds 5 to 15 knots becoming northwest. Showers likely with a chance of thunderstorms early, then a chance of showers. Some thunderstorms may produce gusty winds early. Waves 2 to 4 feet subsiding to 1 to 2 feet. .FRIDAY...Northwest winds 10 knots or less becoming south. Waves 1 foot or less. .FRIDAY NIGHT...Southeast winds 10 knots or less becoming east. Waves 1 foot or less. .SATURDAY...Southeast winds 10 to 15 knots becoming west 15 to 20 knots. Rain showers. Waves 2 feet or less building to 2 to 4 feet. .SUNDAY...West winds 15 to 20 knots becoming northwest. A chance of rain showers. Waves 3 to 6 feet building to 4 to 7 feet. Waves occasionally around 9 feet. .MONDAY...Northwest winds 15 to 20 knots becoming southwest 10 to 15 knots. Waves 4 to 7 feet subsiding to 1 to 3 feet. Waves occasionally around 9 feet. Winds and waves higher in and near thunderstorms. $$ LOZ063>065-162100- Lake Ontario open waters from Hamlin Beach to the Saint Lawrence River- 1236 PM EDT Thu Apr 16 2026 .THIS AFTERNOON...Southwest winds 10 to 15 knots. Showers with a chance of thunderstorms. Some thunderstorms may produce gusty winds. Waves 1 to 3 feet. .TONIGHT...Southwest winds 5 to 15 knots becoming northwest. Showers with a chance of thunderstorms early, then a chance of showers from late evening on. Some thunderstorms may produce gusty winds early. Waves 1 to 3 feet. .FRIDAY...North winds 10 knots or less becoming west. A chance of showers in the morning. Waves 2 feet or less. .FRIDAY NIGHT...West winds 10 knots or less becoming southeast. Waves 1 foot or less. .SATURDAY...Southeast winds 15 to 20 knots becoming west. Rain showers. Waves 1 to 3 feet building to 3 to 5 feet. .SUNDAY...West winds 15 to 25 knots becoming northwest. Rain showers likely during the day, then a chance of rain showers Sunday night. Waves 3 to 6 feet building to 5 to 9 feet. Waves occasionally around 11 feet. .MONDAY...Northwest winds 15 to 20 knots becoming west 10 to 15 knots. Waves 5 to 9 feet subsiding to 3 to 5 feet. Waves occasionally around 11 feet. Winds and waves higher in and near thunderstorms. $$ LOZ061-162100- MAFOR 1615/ ONTARIO WEST 1/2 11510 11526 11516 11600 13700 11800. A chance of thunderstorms this afternoon and evening. Waves 1 to 3 feet building to 2 to 4 feet this afternoon. Waves 2 to 4 feet subsiding to 1 to 2 feet tonight. Waves 2 feet or less Friday morning. ONTARIO EAST 1/2 11406 12516 12600 12700 11800. A chance of thunderstorms this afternoon and evening. Waves 1 to 3 feet. $$  707 FZUS61 KBUF 161638 GLFSL Forecast for the Saint Lawrence River including the Thousand Islands Region National Weather Service Buffalo NY 1237 PM EDT Thu Apr 16 2026 SLZ022-024-162100- Saint Lawrence River from Cape Vincent to Saint Regis 1237 PM EDT Thu Apr 16 2026 .THIS AFTERNOON...South winds 5 to 10 knots becoming southwest. Showers with a chance of thunderstorms. .TONIGHT...Southwest winds 10 knots or less becoming north. Showers with a chance of thunderstorms early, then showers likely late in the evening. A chance of showers after midnight. .FRIDAY...North winds less than 10 knots becoming northeast. Mostly cloudy in the morning, then becoming partly sunny. .FRIDAY NIGHT...Northeast winds less than 10 knots. Mainly clear in the evening, then becoming partly cloudy. .SATURDAY...Southeast winds 10 to 15 knots becoming southwest. A chance of showers during the day, then showers Saturday night. .SUNDAY...West winds 5 to 15 knots becoming northwest. Rain showers likely during the day, then a chance of rain showers Sunday night. .MONDAY...Northwest winds 10 knots or less becoming southwest. Partly cloudy. Winds and waves higher in and near thunderstorms. $$