


Great Lakes Forecast
Issued by NWS
Issued by NWS
300 FZUS61 KBUF 121402 GLFLO Open Lake Forecast for Lake Ontario National Weather Service Buffalo NY 1002 AM EDT Sun Oct 12 2025 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 just offshore of the Carolinas today will move north to just offshore of the Delmarva Monday. Meanwhile, a 30.5 inch high will remain in place over the Canadian Maritimes through Monday. The east coast low will move east into the Atlantic Tuesday, while a ridge of high pressure averaging 30.2 inches building into the lower Great Lakes. A cold front will move south across the lake Tuesday night. An expansive 30.3 inch high will then build from the upper Great Lakes Wednesday to Quebec and the lower Great Lakes by Thursday night. LOZ062-122100- Lake Ontario open waters from the Niagara River to Hamlin Beach- 1002 AM EDT Sun Oct 12 2025 .THIS AFTERNOON...East winds 15 to 20 knots. Waves 3 to 5 feet. .TONIGHT...East winds 15 to 20 knots. Waves 3 to 5 feet. .MONDAY...East winds 15 to 20 knots becoming northeast. Waves 2 to 4 feet. .MONDAY NIGHT...East winds 5 to 15 knots becoming northeast. Waves 2 to 4 feet subsiding to 1 to 2 feet. .TUESDAY...North winds 5 to 10 knots increasing to 15 to 20 knots. Waves 2 feet or less building to 3 to 5 feet. .WEDNESDAY...North winds 15 to 20 knots. Waves 3 to 5 feet subsiding to 2 to 4 feet. .THURSDAY...North winds 15 to 20 knots diminishing to 10 to 15 knots. Waves 2 to 4 feet subsiding to 1 to 2 feet. $$ LOZ063>065-122100- Lake Ontario open waters from Hamlin Beach to the Saint Lawrence River- 1002 AM EDT Sun Oct 12 2025 .THIS AFTERNOON...East winds 10 to 15 knots increasing to 15 to 20 knots. Waves 1 to 3 feet. .TONIGHT...East winds 15 to 20 knots diminishing to 10 to 15 knots. A chance of showers late. Waves 2 to 4 feet. .MONDAY...Northeast winds 10 to 15 knots increasing to 15 to 20 knots. A chance of showers. Waves 1 to 3 feet building to 3 to 5 feet. .MONDAY NIGHT...Northeast winds 15 to 20 knots diminishing to 5 to 15 knots. A chance of showers. Waves 3 to 5 feet subsiding to 1 to 3 feet. .TUESDAY...North winds 5 to 10 knots increasing to 15 to 25 knots. Waves 2 feet or less building to 3 to 6 feet. .WEDNESDAY...North winds 15 to 25 knots. Waves 3 to 6 feet. .THURSDAY...North winds 15 to 20 knots. Waves 3 to 5 feet subsiding to 1 to 3 feet. $$ LOZ061-122100- MAFOR 1215/ ONTARIO WEST 1/2 14220 11210 11220 12210. Waves 3 to 5 feet. ONTARIO EAST 1/2 11210 11110 12220 12210 12110. A chance of showers overnight and Monday morning. Waves 1 to 3 feet this afternoon. Waves 2 to 4 feet subsiding to 1 to 3 feet tonight. Waves 1 to 3 feet building to 2 to 4 feet Monday morning. $$