FZUS61 KBUF 210202 GLFLO Open Lake Forecast for Lake Ontario National Weather Service Buffalo NY 1002 PM EDT Sat Jun 20 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...An unseasonably strong 29.2 inch low over the Canadian Maritimes will finally exit eastward into the northern Atlantic tonight. A weak ridge of high pressure averaging 29.9 inches will then build over the Great Lakes tonight through Sunday. A 29.7 inch low is then forecast to move south of the lower Great Lakes Monday and Monday night, before moving off the New England coast by Tuesday. A broad area of high pressure averaging 30.1 inches will advance over the eastern Great Lakes region Tuesday and Wednesday, before exiting east into New England on Thursday as a weak 29.8 inch low moves east into the central Great Lakes. LOZ062-210900- Lake Ontario open waters from the Niagara River to Hamlin Beach- 1002 PM EDT Sat Jun 20 2026 .OVERNIGHT...Northwest winds 10 knots or less. Waves 2 feet or less. .SUNDAY...West winds 5 to 10 knots becoming southwest. Waves 1 foot or less. .SUNDAY NIGHT...West winds less than 10 knots becoming southeast. Waves 1 foot or less. .MONDAY...East winds 10 knots or less increasing to 10 to 15 knots. A chance of showers. Waves 2 feet or less. .MONDAY NIGHT...East winds 5 to 15 knots becoming north. A chance of showers in the evening. Waves 1 to 2 feet. .TUESDAY...Northwest winds 5 to 10 knots. Waves 1 foot or less. .WEDNESDAY...West winds less than 10 knots becoming south. A chance of showers Wednesday night. Waves 1 foot or less. .THURSDAY...East winds 10 knots or less becoming southwest. A chance of showers. Waves 1 foot or less. $$ LOZ063>065-210900- Lake Ontario open waters from Hamlin Beach to the Saint Lawrence River- 1002 PM EDT Sat Jun 20 2026 .OVERNIGHT...West winds 5 to 10 knots. Waves 1 to 3 feet. .SUNDAY...West winds 5 to 10 knots. Waves 2 feet or less. .SUNDAY NIGHT...West winds 10 knots or less becoming south. Waves 1 foot or less. .MONDAY...Southeast winds 5 to 10 knots. Showers likely. Waves 1 foot or less. .MONDAY NIGHT...East winds 5 to 10 knots becoming north. Showers likely in the evening, then a chance of showers overnight. Waves 1 foot or less. .TUESDAY...Northwest winds 5 to 10 knots. Waves 2 feet or less. .WEDNESDAY...West winds 10 knots or less becoming south. A chance of showers Wednesday night. Waves 1 foot or less. .THURSDAY...Southeast winds 10 knots or less becoming southwest. A chance of showers during the day, then showers likely Thursday night. Waves 1 foot or less. $$ LOZ061-210900- MAFOR 2103/ ONTARIO WEST 1/2 12700 13600 11500 12600. Waves 2 feet or less. ONTARIO EAST 1/2 15600 11600 11500. Waves 1 to 3 feet overnight. Waves 2 feet or less Sunday and Sunday evening. $$