Great Lakes Forecast
Issued by NWS
Issued by NWS
754 FZUS61 KBUF 172003 GLFLO Open Lake Forecast for Lake Ontario National Weather Service Buffalo NY 403 PM EDT Fri Jul 17 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 30.0 inch ridge of high pressure will slide east of the Lake this evening to the Atlantic shoreline and in its wake a warm front will lift northeastward across the Lake tonight through tomorrow morning. Following this warm front a cold front will slice across the Lake Saturday afternoon and evening with this front attached to a 29.4 inch area of low pressure crossing southern Canada. A 30.0 inch area of high pressure will build across the Great Lakes region from west to east Sunday into Monday, followed by another cold front Tuesday night with this front attached to a 29.5 inch area of low pressure near James Bay. A secondary cold front will cross the Lake Wednesday. LOZ062-180300- Lake Ontario open waters from the Niagara River to Hamlin Beach- 403 PM EDT Fri Jul 17 2026 .TONIGHT...Southeast winds 5 to 15 knots becoming south. Smoke through the early overnight. Waves 1 foot or less. .SATURDAY...Southwest winds 15 to 20 knots becoming west. Showers likely early, then a chance of showers and thunderstorms late in the morning. Showers with a chance of thunderstorms in the afternoon. Some thunderstorms may produce gusty winds in the afternoon. Waves 1 to 3 feet building to 3 to 6 feet. .SATURDAY NIGHT...West winds 15 to 20 knots becoming north. Showers likely in the evening. Waves 3 to 5 feet. .SUNDAY...North winds 5 to 15 knots becoming west. Waves 1 to 3 feet. .SUNDAY NIGHT...West winds 10 knots or less becoming southwest. Waves 1 foot or less. .MONDAY...Southwest winds 5 to 15 knots becoming south 15 to 20 knots. Showers likely Monday night. Waves 1 to 3 feet. .TUESDAY...South winds 15 to 25 knots becoming west. Showers with a chance of thunderstorms. Waves 3 to 5 feet. .WEDNESDAY...West winds 15 to 20 knots. A chance of showers during the day. Waves 3 to 6 feet. Winds and waves higher in and near thunderstorms. $$ LOZ063>065-180300- Lake Ontario open waters from Hamlin Beach to the Saint Lawrence River- 403 PM EDT Fri Jul 17 2026 .TONIGHT...Southeast winds 5 to 15 knots becoming south 15 to 20 knots. Areas of smoke this evening. Waves 1 foot or less building to 1 to 3 feet. .SATURDAY...South winds 15 to 25 knots becoming west. Showers in the morning, then showers with a chance of thunderstorms in the afternoon. Some thunderstorms may produce gusty winds in the afternoon. Waves 2 to 4 feet building to 3 to 6 feet. .SATURDAY NIGHT...West winds 15 to 25 knots becoming northwest. Showers with a chance of thunderstorms in the evening. Some thunderstorms may produce gusty winds in the evening. Waves 3 to 6 feet building to 4 to 7 feet, then subsiding to 3 to 6 feet. Waves occasionally around 9 feet. .SUNDAY...Northwest winds 15 to 20 knots becoming west 10 to 15 knots. Waves 3 to 5 feet subsiding to 1 to 3 feet. .SUNDAY NIGHT...West winds 5 to 15 knots. Waves 1 to 3 feet. .MONDAY...Southwest winds 5 to 15 knots becoming south 15 to 20 knots. A chance of showers Monday night. Waves 2 feet or less building to 2 to 4 feet. .TUESDAY...South winds 15 to 25 knots becoming west. Showers with a chance of thunderstorms. Waves 3 to 5 feet building to 3 to 6 feet. .WEDNESDAY...West winds 15 to 25 knots. Showers likely during the day, then a chance of showers Wednesday night. Waves 4 to 7 feet subsiding to 3 to 6 feet. Waves occasionally around 9 feet. Winds and waves higher in and near thunderstorms. $$ LOZ061-180300- MAFOR 1721/ ONTARIO WEST 1/2 13300 11310 11410 12520 11536. A chance of thunderstorms Saturday afternoon. Waves 2 feet or less tonight. Waves 1 to 3 feet building to 3 to 6 feet Saturday. ONTARIO EAST 1/2 12300 11400 11410 11420 11426 11520 11526. A chance of thunderstorms Saturday afternoon. Waves 1 foot or less building to 1 to 3 feet tonight. Waves 2 to 4 feet building to 3 to 6 feet Saturday. $$