FZUS61 KBUF 120209 GLFLO Open Lake Forecast for Lake Ontario National Weather Service Buffalo NY 1009 PM EDT Wed Mar 11 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...Low pressure will deepen to 29.2 inches as it moves from Lake Huron this evening to southern Quebec overnight before reaching the Canadian Maritimes Thursday evening. A ridge of high pressure averaging 30.1 inches will then build into the Ohio Valley and lower Great Lakes Thursday afternoon and evening before drifting to the eastern seaboard Friday. A 29.0 inch low will then move from the upper Great Lakes Friday morning to the Ottawa Valley Friday night while weakening to 29.4 inches. This low will continue east to the Canadian Maritimes Saturday as a 30.3 inch high builds into the lower Great Lakes. A 30.3 inch surface high will ridge across the lake Saturday night, and move east of the lake Sunday. Meanwhile, a 29.5 inch surface low over the mid Mississippi Valley Sunday morning will track northeastward and deepen to 28.9 inches just to the west of the lake Monday morning. LOZ062-120900- Lake Ontario open waters from the Niagara River to Hamlin Beach- 1009 PM EDT Wed Mar 11 2026 ...GALE WARNING IN EFFECT UNTIL 8 AM EDT THURSDAY... .REST OF TONIGHT...West winds to 30 knots increasing to 35 knot gales. Rain showers late this evening, then a chance of rain showers after midnight. A chance of snow showers late. Waves 5 to 7 feet building to 10 to 14 feet. Waves occasionally around 18 feet. .THURSDAY...West winds to 30 knots. A chance of snow showers early. Waves 9 to 12 feet subsiding to 5 to 8 feet. Waves occasionally around 15 feet. .THURSDAY NIGHT...Northwest winds 15 to 25 knots becoming southwest and diminishing to 10 to 15 knots. Waves 4 to 7 feet subsiding to 1 to 2 feet. Waves occasionally around 9 feet. .FRIDAY...Southeast winds 15 to 25 knots becoming southwest to 30 knots. Rain and snow. Waves 1 to 3 feet building to 5 to 8 feet. Waves occasionally around 10 feet. .FRIDAY NIGHT...Southwest winds to 30 knots becoming west and increasing to 35 knot gales. Rain likely in the evening. Waves 7 to 10 feet building to 11 to 15 feet. Waves occasionally around 19 feet. .SATURDAY...West gales to 35 knots becoming northeast and diminishing to 5 to 10 knots. Waves 10 to 14 feet subsiding to 1 to 2 feet. Waves occasionally around 18 feet. .SUNDAY...East winds 15 to 25 knots becoming south to 30 knots. Rain and snow showers. Waves 2 to 4 feet building to 5 to 9 feet. Waves occasionally around 11 feet. .MONDAY...Southwest gales to 35 knots becoming west. Rain showers with snow showers likely during the day. Waves 8 to 11 feet building to 10 to 15 feet. Waves occasionally around 19 feet. $$ LOZ063>065-120900- Lake Ontario open waters from Hamlin Beach to the Saint Lawrence River- 1009 PM EDT Wed Mar 11 2026 ...GALE WARNING IN EFFECT THROUGH THURSDAY MORNING... .REST OF TONIGHT...West winds 15 to 25 knots increasing to 35 knot gales after midnight. Rain showers, then a chance of rain and snow showers late. Waves 3 to 6 feet building to 12 to 16 feet. Waves occasionally around 20 feet. .THURSDAY...West winds to 30 knots. A chance of snow showers in the morning. Waves 10 to 15 feet subsiding to 7 to 11 feet. Waves occasionally around 19 feet. .THURSDAY NIGHT...Northwest winds to 30 knots becoming west and diminishing to around 10 knots overnight. Waves 6 to 10 feet subsiding to 2 to 4 feet. Waves occasionally around 13 feet. .FRIDAY...South winds 10 to 15 knots becoming southwest and increasing to 30 knots in the afternoon. Rain and snow. Waves 1 to 3 feet building to 4 to 7 feet. Waves occasionally around 9 feet. .FRIDAY NIGHT...Southwest winds 20 to 25 knots becoming west and increasing to 40 knot gales overnight. Rain with a chance of snow showers in the evening, then a chance of snow showers overnight. Waves 5 to 8 feet building to 14 to 18 feet. Waves occasionally around 23 feet. .SATURDAY...West gales to 40 knots becoming north and diminishing to 10 to 15 knots. Waves 14 to 18 feet subsiding to 2 to 4 feet. Waves occasionally around 23 feet. .SUNDAY...East winds 15 to 20 knots becoming southeast and increasing to 40 knot gales. Snow showers likely during the day, then rain and snow showers likely Sunday night. Waves 1 to 3 feet building to 8 to 11 feet. Waves occasionally around 14 feet. .MONDAY...South gales to 40 knots becoming west to 35 knots. Rain and snow showers during the day, then a chance of snow and rain showers Monday night. Waves 7 to 10 feet building to 12 to 17 feet. Waves occasionally around 22 feet. $$ LOZ061-120900- MAFOR 1203/ ONTARIO WEST 1/2...GALE WARNING IN EFFECT...11640 11650 12640 13630 11720. Waves 5 to 7 feet building to 10 to 14 feet, and occasionally around 18 feet overnight. Waves 10 to 13 feet subsiding to 5 to 9 feet, and occasionally around 16 feet Thursday. Waves 4 to 7 feet, and occasionally around 9 feet Thursday evening. ONTARIO EAST 1/2...GALE WARNING IN EFFECT...11646 11650 12640 11630 11640 11630 11730. A chance of snow showers overnight and Thursday morning. Waves 3 to 6 feet building to 12 to 16 feet, and occasionally around 20 feet overnight. Waves 10 to 15 feet subsiding to 7 to 11 feet, and occasionally around 19 feet Thursday. Waves 6 to 10 feet, and occasionally around 13 feet Thursday evening. $$