FZUS61 KBUF 042002 GLFLO Open Lake Forecast for Lake Ontario National Weather Service Buffalo NY 402 PM EDT Mon May 4 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 29.1 inch low over Hudson Bay tonight through Tuesday will weaken to 29.3 inches as it moves to northern Quebec through Wednesday. Its trailing wavy cold front will slowly cross the lake late Tuesday, then will drift across New England Wednesday and out to sea Thursday. A 30.1 inch high over the Tennessee and Ohio Valleys Thursday night will slide to the mid-Atlantic coastline Friday. LOZ062-050300- Lake Ontario open waters from the Niagara River to Hamlin Beach- 402 PM EDT Mon May 4 2026 .TONIGHT...Southwest winds 15 to 20 knots. A chance of showers late this evening. Waves 2 to 4 feet building to 3 to 5 feet. .TUESDAY...Southwest winds 15 to 20 knots becoming west 10 to 15 knots. A chance of showers through early afternoon, then showers likely late. Waves 3 to 5 feet subsiding to 1 to 3 feet. .TUESDAY NIGHT...Southwest winds 5 to 10 knots becoming east. Rain likely in the evening, then rain overnight. Waves 2 feet or less. .WEDNESDAY...Northeast winds 5 to 10 knots becoming west. Rain in the morning, then showers likely in the afternoon. Waves 1 foot or less. .WEDNESDAY NIGHT...West winds 5 to 10 knots. Waves 1 foot or less. .THURSDAY...West winds 5 to 10 knots. Waves 1 foot or less. .FRIDAY...West winds 5 to 10 knots becoming southwest. Waves 1 to 2 feet. .SATURDAY...Southwest winds 5 to 10 knots becoming west. A chance of showers. Waves 1 to 2 feet. $$ LOZ063>065-050300- Lake Ontario open waters from Hamlin Beach to the Saint Lawrence River- 402 PM EDT Mon May 4 2026 .TONIGHT...South winds 10 to 15 knots increasing to 15 to 20 knots. A chance of showers after midnight. Waves 1 to 3 feet building to 2 to 4 feet. .TUESDAY...Southwest winds 15 to 20 knots becoming west 10 to 15 knots. A chance of showers early, then showers likely late in the morning. Showers likely with a chance of thunderstorms in the afternoon. Waves 2 to 4 feet. .TUESDAY NIGHT...West winds 5 to 15 knots becoming south less than 10 knots. Rain with a chance of thunderstorms in the evening, then rain overnight. Waves 1 to 3 feet subsiding to 1 foot or less. .WEDNESDAY...North winds 5 to 10 knots becoming northwest. Rain in the morning, then showers in the afternoon. Waves 1 foot or less. .WEDNESDAY NIGHT...West winds 5 to 10 knots. A chance of showers. Waves 2 feet or less. .THURSDAY...West winds 5 to 15 knots. Waves 1 to 2 feet. .FRIDAY...West winds 5 to 15 knots becoming southwest. Waves 1 to 3 feet. .SATURDAY...Southwest winds 5 to 15 knots. A chance of showers. Waves 1 to 2 feet. Winds and waves higher in and near thunderstorms. $$ LOZ061-050300- MAFOR 0421/ ONTARIO WEST 1/2 11510 12420 13520 11610 11710. A chance of showers Tuesday afternoon. Waves 2 to 4 feet building to 3 to 5 feet tonight. Waves 3 to 5 feet subsiding to 1 to 3 feet Tuesday. ONTARIO EAST 1/2 11400 11410 13420 11520 11510 11610. A chance of showers Tuesday. Waves 1 to 3 feet building to 2 to 4 feet tonight. Waves 2 to 4 feet Tuesday. $$