FZUS61 KBUF 092002 GLFLO Open Lake Forecast for Lake Ontario National Weather Service Buffalo NY 402 PM EDT Thu Jul 9 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 weak cold front will cross the Lake tonight through early Friday. Another 30.0 inch high will then build across the upper Great Lakes Friday and the lower Great Lakes over the weekend, expanding east into New England Monday, then drifting south into the Mid-Atlantic Tuesday. This will allow for a warm front to pass across the lake Tuesday. LOZ062-100300- Lake Ontario open waters from the Niagara River to Hamlin Beach- 402 PM EDT Thu Jul 9 2026 .TONIGHT...West winds 10 knots or less becoming northwest. Showers likely with a chance of thunderstorms early, then a chance of showers from late evening on. Waves 1 foot or less. .FRIDAY...North winds less than 10 knots. Waves 1 foot or less. .FRIDAY NIGHT...Light and variable winds becoming northeast 5 to 10 knots. Waves 1 foot or less. .SATURDAY...Northeast winds 10 knots or less becoming east. Waves 2 feet or less. .SATURDAY NIGHT...Northeast winds less than 10 knots. Waves 1 foot or less. .SUNDAY...Light and variable winds. Waves 1 foot or less. .MONDAY...Southwest winds 10 knots or less. Waves 2 feet or less. .TUESDAY...Southwest winds 10 to 15 knots becoming west 15 to 20 knots. Waves 1 to 3 feet building to 3 to 5 feet. Winds and waves higher in and near thunderstorms. $$ LOZ063>065-100300- Lake Ontario open waters from Hamlin Beach to the Saint Lawrence River- 402 PM EDT Thu Jul 9 2026 .TONIGHT...Northwest winds 5 to 10 knots. A chance of showers and thunderstorms early, then a chance of showers late this evening. A chance of showers late. Waves 1 foot or less. .FRIDAY...Northwest winds less than 10 knots. A chance of showers early. Waves 1 foot or less. .FRIDAY NIGHT...Northwest winds 10 knots or less becoming northeast 10 to 15 knots. Waves 2 feet or less. .SATURDAY...Northeast winds 5 to 15 knots. Waves 2 feet or less. .SATURDAY NIGHT...North winds 10 knots or less becoming northeast. Waves 1 foot or less. .SUNDAY...Northeast winds 10 knots or less becoming south. Waves 1 foot or less. .MONDAY...South winds 5 to 10 knots becoming southwest. Waves 2 feet or less. .TUESDAY...Southwest winds 10 to 15 knots becoming west 15 to 20 knots. Waves 1 to 3 feet building to 3 to 5 feet. Winds and waves higher in and near thunderstorms. $$ LOZ061-100300- MAFOR 0921/ ONTARIO WEST 1/2 11706 11500 12600 13800 11100. A chance of thunderstorms this evening. Waves 1 foot or less. ONTARIO EAST 1/2 11700 13600 11700 11800 12700. A chance of showers and thunderstorms this evening. Waves 1 foot or less. $$