FZUS61 KBUF 130803 GLFLO Open Lake Forecast for Lake Ontario National Weather Service Buffalo NY 403 AM EDT Fri Mar 13 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 29.0 inch low will move from the upper Great Lakes this morning to the Ottawa Valley tonight while weakening to 29.5 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 high will then ridge across the lake Saturday night, before moving 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, before pushing northeastward across Quebec through the remainder of Monday and Tuesday. This low will sweep a strong cold front across the lake Monday afternoon, with a 30.3 inch high then building across the Great Lakes and Ohio Valley Tuesday. LOZ062-131500- Lake Ontario open waters from the Niagara River to Hamlin Beach- 403 AM EDT Fri Mar 13 2026 ...GALE WARNING IN EFFECT FROM 3 PM EDT THIS AFTERNOON THROUGH SATURDAY MORNING... .TODAY...Southeast winds 10 to 15 knots becoming south and increasing to 35 knot gales. Snow showers. Rain and snow showers late. Waves 1 to 2 feet building to 7 to 10 feet. Waves occasionally around 13 feet. .TONIGHT...Southwest gales to 40 knots becoming west to 35 knots. Rain showers early, then rain and snow showers likely late in the evening. A chance of rain and snow showers after midnight. Waves 10 to 15 feet. Waves occasionally around 19 feet. .SATURDAY...West gales to 35 knots diminishing to 15 to 25 knots. A chance of snow showers in the morning. Waves 11 to 15 feet subsiding to 4 to 7 feet. Waves occasionally around 19 feet. .SATURDAY NIGHT...West winds 15 to 20 knots becoming east 5 to 15 knots. A chance of snow showers overnight. Waves 3 to 5 feet subsiding to 1 to 3 feet. .SUNDAY...East winds 15 to 25 knots becoming southeast to 30 knots. Snow and rain showers 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...Southeast winds to 30 knots becoming west and increasing to 40 knot gales. Rain showers during the day, then rain showers with a chance of snow showers Monday night. Waves 5 to 8 feet building to 13 to 17 feet. Waves occasionally around 22 feet. .TUESDAY...West gales to 35 knots diminishing to 15 to 25 knots. A chance of snow showers during the day. Waves 12 to 16 feet subsiding to 7 to 10 feet. Waves occasionally around 20 feet. $$ LOZ063>065-131500- Lake Ontario open waters from Hamlin Beach to the Saint Lawrence River- 403 AM EDT Fri Mar 13 2026 ...GALE WARNING IN EFFECT FROM THIS AFTERNOON THROUGH SATURDAY AFTERNOON... .TODAY...South winds 10 to 15 knots becoming southeast and increasing to 30 knots this afternoon. A chance of snow showers late this morning. Snow showers early this afternoon, then snow and rain showers late. Waves 1 to 3 feet building to 5 to 8 feet. Waves occasionally around 10 feet. .TONIGHT...Southwest gales to 35 knots becoming west. Rain and snow showers. Waves 7 to 10 feet building to 12 to 16 feet. Waves occasionally around 20 feet. .SATURDAY...West gales to 40 knots diminishing to 30 knots. Snow showers with rain showers likely in the morning, then a chance of snow showers in the afternoon. Waves 14 to 19 feet subsiding to 10 to 15 feet. Waves occasionally around 24 feet. .SATURDAY NIGHT...West winds 15 to 25 knots becoming east and diminishing to 5 to 15 knots. Waves 7 to 10 feet subsiding to 2 feet or less. Waves occasionally around 13 feet. .SUNDAY...East winds 15 to 25 knots becoming southeast and increasing to 40 knot gales. Snow showers likely with a chance of rain showers during the day, then a chance of rain showers Sunday night. Waves 2 to 4 feet building to 9 to 12 feet. Waves occasionally around 15 feet. .MONDAY...Southeast gales to 40 knots becoming southwest. Rain showers during the day, then rain showers with snow showers likely Monday night. Waves 7 to 11 feet building to 14 to 18 feet. Waves occasionally around 23 feet. .TUESDAY...West gales to 40 knots diminishing to 30 knots. A chance of snow showers during the day. Waves 13 to 18 feet subsiding to 10 to 14 feet. Waves occasionally around 23 feet. $$ LOZ061-131500- MAFOR 1309/ ONTARIO WEST 1/2...GALE WARNING IN EFFECT...11410 11330 11347 11357 11456 11556 11550 11650. Waves 1 to 2 feet building to 7 to 10 feet, and occasionally around 13 feet today. Waves 10 to 15 feet, and occasionally around 19 feet tonight. ONTARIO EAST 1/2...GALE WARNING IN EFFECT...11510 11320 11330 11347 11447 12547 11550. Waves 1 to 3 feet building to 5 to 8 feet, and occasionally around 10 feet today. Waves 6 to 9 feet building to 11 to 15 feet, and occasionally around 19 feet tonight. $$