


Great Lakes Forecast
Issued by NWS
Issued by NWS
421 FZUS61 KBUF 122002 GLFLO Open Lake Forecast for Lake Ontario National Weather Service Buffalo NY 402 PM 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 will move north to just offshore of the Delmarva by 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. LOZ062-130300- Lake Ontario open waters from the Niagara River to Hamlin Beach- 402 PM EDT Sun Oct 12 2025 .TONIGHT...East winds 15 to 20 knots. Waves 3 to 5 feet. .MONDAY...East winds 15 to 20 knots diminishing to 10 to 15 knots. Waves 2 to 4 feet. .MONDAY NIGHT...East winds 5 to 15 knots becoming northeast. Waves 1 to 3 feet. .TUESDAY...North winds 5 to 10 knots becoming west. Waves 2 feet or less. .TUESDAY NIGHT...Northwest winds 10 to 15 knots becoming north 15 to 20 knots. Waves 1 to 3 feet building to 2 to 4 feet. .WEDNESDAY...North winds 15 to 20 knots. Waves 2 to 4 feet. .THURSDAY...North winds 5 to 15 knots. Waves 1 to 3 feet. .FRIDAY...Northeast winds 10 knots or less becoming south. A chance of showers Friday night. Waves 1 foot or less. $$ LOZ063>065-130300- Lake Ontario open waters from Hamlin Beach to the Saint Lawrence River- 402 PM EDT Sun Oct 12 2025 .TONIGHT...East winds 15 to 20 knots. A chance of showers after midnight. Showers likely late. Waves 1 to 3 feet building to 2 to 4 feet. .MONDAY...East winds 10 to 15 knots. A chance of showers. Waves 2 to 4 feet subsiding to 1 to 3 feet. .MONDAY NIGHT...East winds 5 to 15 knots becoming northeast. A chance of showers. Waves 1 to 3 feet. .TUESDAY...Northeast winds 5 to 10 knots becoming west. Waves 2 feet or less. .TUESDAY NIGHT...West winds 10 to 15 knots becoming north 15 to 20 knots. Waves 1 to 2 feet building to 3 to 6 feet. .WEDNESDAY...North winds 15 to 25 knots. Waves 3 to 6 feet subsiding to 3 to 5 feet. .THURSDAY...North winds 15 to 20 knots diminishing to 10 to 15 knots. Waves 3 to 5 feet subsiding to 1 to 3 feet. .FRIDAY...North winds 5 to 10 knots becoming south. A chance of showers Friday night. Waves 2 feet or less. $$ LOZ061-130300- MAFOR 1221/ ONTARIO WEST 1/2 12220 11320 12220 13210. Waves 3 to 5 feet subsiding to 2 to 4 feet, then building to 3 to 5 feet tonight. Waves 2 to 4 feet Monday. ONTARIO EAST 1/2 13220 13210 12110. A chance of showers overnight and Monday morning. Waves 1 to 3 feet building to 2 to 4 feet tonight. Waves 1 to 3 feet Monday. $$