FZUS61 KBUF 190209 GLFLO Open Lake Forecast for Lake Ontario National Weather Service Buffalo NY 1009 PM EDT Wed Mar 18 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 30.4 inch high ridged from the lower Ohio Valley to the lake will slide east to the East Coast by this evening. Following the passage of a weak warm front, a 30.2 inch high will build across the Great Lakes region Thursday and Thursday evening. A 29.8 inch low will settle from the Upper Great Lakes to the Lower Lakes Friday, with another 29.6 inch low then moving from near James Bay to the Canadian Maritimes between Saturday and Sunday and pushing a cold front across the lake. A 30.4 inch high is then forecast to build across the Great Lakes on Monday. LOZ062-190900- Lake Ontario open waters from the Niagara River to Hamlin Beach- 1009 PM EDT Wed Mar 18 2026 .REST OF TONIGHT...South winds 10 to 15 knots. Scattered flurries late this evening, then scattered snow showers after midnight. Waves 1 to 2 feet. .THURSDAY...South winds 10 to 15 knots becoming west. A chance of snow showers in the morning. Waves 1 to 2 feet. .THURSDAY NIGHT...West winds 10 knots or less becoming southwest. Waves 1 foot or less. .FRIDAY...South winds 5 to 10 knots becoming southeast. A chance of rain and snow showers in the morning, then rain showers likely in the afternoon. Waves 2 feet or less. .FRIDAY NIGHT...East winds around 10 knots becoming northwest. Rain showers likely in the evening, then a chance of rain showers overnight. Waves 1 to 2 feet. .SATURDAY...West winds 10 to 15 knots becoming southwest 15 to 20 knots. A chance of rain and snow showers Saturday night. Waves 1 to 2 feet building to 2 to 4 feet. .SUNDAY...Northwest winds 15 to 25 knots becoming north. A chance of rain and snow showers. Waves 3 to 6 feet building to 4 to 7 feet. Waves occasionally around 9 feet. .MONDAY...North winds 15 to 25 knots becoming east and diminishing to 10 to 15 knots. Waves 3 to 6 feet subsiding to 1 to 3 feet. $$ LOZ063>065-190900- Lake Ontario open waters from Hamlin Beach to the Saint Lawrence River- 1009 PM EDT Wed Mar 18 2026 .REST OF TONIGHT...South winds 15 to 20 knots. Scattered flurries after midnight. Waves 1 to 3 feet building to 2 to 4 feet. .THURSDAY...South winds 15 to 20 knots becoming southwest 10 to 15 knots. A chance of snow showers in the morning, then a chance of rain and snow showers early in the afternoon. Waves 3 to 5 feet subsiding to 1 to 3 feet. .THURSDAY NIGHT...West winds 10 knots or less. Waves 2 feet or less. .FRIDAY...South winds 10 knots or less becoming southeast. A chance of rain and snow showers in the morning, then rain showers likely in the afternoon. Waves 1 foot or less. .FRIDAY NIGHT...East winds 10 to 15 knots becoming northwest. Rain showers likely in the evening, then a chance of rain showers overnight. Waves 2 feet or less. .SATURDAY...West winds 10 to 15 knots becoming southwest 15 to 20 knots. A chance of rain showers during the day, then a chance of rain and snow showers Saturday night. Waves 1 to 3 feet building to 3 to 5 feet. .SUNDAY...Northwest winds 15 to 25 knots becoming north to 30 knots. A chance of rain and snow showers. Waves 3 to 6 feet building to 5 to 8 feet. Waves occasionally around 10 feet. .MONDAY...North winds 15 to 25 knots becoming northeast. Waves 5 to 8 feet subsiding to 1 to 3 feet. Waves occasionally around 10 feet. $$ LOZ061-190900- MAFOR 1903/ ONTARIO WEST 1/2 14410 11500 12600 11700. A chance of snow showers overnight and Thursday morning. Waves 1 to 2 feet. ONTARIO EAST 1/2 14420 11420 11510 12600. A chance of snow showers Thursday morning. Waves 1 to 3 feet building to 2 to 4 feet overnight. Waves 3 to 5 feet subsiding to 1 to 3 feet Thursday. Waves 2 feet or less Thursday evening. $$