FZUS61 KBUF 132010 GLFLO Open Lake Forecast for Lake Ontario National Weather Service Buffalo NY 410 PM EDT Mon Apr 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 29.6 inch low will move into the central Great Lakes Tuesday morning before weakening across the Saint Lawrence valley Tuesday night. Another 29.6 inch low will move into the central Great Lakes Wednesday night before reaching southern Quebec Thursday night. A 30.0 inch high is then forecast to build from the central Great Lakes Friday to the lower Great Lakes Saturday. LOZ062-140300- Lake Ontario open waters from the Niagara River to Hamlin Beach- 410 PM EDT Mon Apr 13 2026 .TONIGHT...West winds 15 to 20 knots becoming east and diminishing to 5 to 10 knots. Waves 2 to 4 feet subsiding to 1 foot or less. .TUESDAY...Southeast winds 10 to 15 knots becoming southwest 15 to 20 knots. Showers with a chance of thunderstorms in the morning, then a chance of showers and thunderstorms in the afternoon. Waves 1 to 2 feet building to 3 to 5 feet. .TUESDAY NIGHT...Southwest winds 15 to 20 knots diminishing to 10 to 15 knots. A chance of showers and thunderstorms in the evening, then showers with a chance of thunderstorms overnight. Waves 3 to 5 feet subsiding to 1 to 2 feet. .WEDNESDAY...Southwest winds 10 to 15 knots increasing to 15 to 20 knots. Showers with a chance of thunderstorms in the morning, then showers likely in the afternoon. Waves 1 to 2 feet. .WEDNESDAY NIGHT...Southwest winds 15 to 20 knots becoming south and diminishing to 5 to 10 knots. Showers. Waves 1 to 2 feet. .THURSDAY...South winds 10 to 15 knots becoming southwest. Showers. Waves 1 to 3 feet. .FRIDAY...West winds 5 to 15 knots becoming east. A chance of showers during the day. Waves 1 to 3 feet subsiding to 1 foot or less. .SATURDAY...Southeast winds 5 to 10 knots becoming southwest and increasing to 15 to 25 knots. Showers likely. Waves 1 to 3 feet building to 3 to 6 feet. Winds and waves higher in and near thunderstorms. $$ LOZ063>065-140300- Lake Ontario open waters from Hamlin Beach to the Saint Lawrence River- 410 PM EDT Mon Apr 13 2026 .TONIGHT...West winds 15 to 25 knots becoming southeast and diminishing to 5 to 10 knots after midnight. Waves 3 to 5 feet subsiding to 1 to 3 feet. .TUESDAY...Southeast winds 5 to 15 knots becoming southwest. Showers likely in the morning, then showers with a chance of thunderstorms in the afternoon. Waves 2 feet or less building to 2 to 4 feet. .TUESDAY NIGHT...West winds 5 to 15 knots becoming southwest. A chance of showers and thunderstorms in the evening, then showers likely with a chance of thunderstorms overnight. Waves 2 to 4 feet subsiding to 1 to 3 feet. .WEDNESDAY...South winds 5 to 10 knots becoming west and increasing to 15 to 20 knots. Showers likely with a chance of thunderstorms in the morning, then showers likely in the afternoon. Waves 1 to 2 feet. .WEDNESDAY NIGHT...Southwest winds 5 to 15 knots becoming south. Showers likely. Waves 2 feet or less. .THURSDAY...South winds 5 to 15 knots becoming west. Showers likely. Waves 1 to 3 feet. .FRIDAY...Northwest winds 5 to 15 knots becoming southeast. A chance of showers during the day. Waves 1 to 3 feet subsiding to 1 foot or less. .SATURDAY...Southeast winds 10 to 15 knots becoming southwest and increasing to 15 to 25 knots. A chance of showers during the day, then showers likely Saturday night. Waves 1 to 3 feet building to 4 to 7 feet. Waves occasionally around 9 feet. Winds and waves higher in and near thunderstorms. $$ LOZ061-140300- MAFOR 1321/ ONTARIO WEST 1/2 12620 11500 11200 11310 11316 12520. A chance of thunderstorms Tuesday. Waves 2 to 4 feet subsiding to 1 foot or less tonight. Waves 1 to 2 feet building to 3 to 5 feet Tuesday. ONTARIO EAST 1/2 11630 11620 11600 11400 11300 11306 11410 11516. A chance of thunderstorms Tuesday afternoon. Waves 3 to 5 feet subsiding to 1 to 3 feet tonight. Waves 2 feet or less Tuesday. $$