FZUS61 KBUF 181403

GLFLO 



Open Lake Forecast for Lake Ontario

National Weather Service Buffalo NY

1003 AM EDT Sat Jul 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 cold front will slice across the Lake this afternoon and evening, 

with this front attached to a 29.4 inch area of low pressure 

crossing southeastern 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 a warm front crossing the Lake Monday night and 

another cold front Tuesday night, with these fronts attached to a 

29.4 inch area of low pressure near James Bay. A secondary cold 

front will cross the Lake Wednesday, with a 30.1 inch high building 

across the lower Great Lakes region Wednesday night through Friday.



LOZ062-182100-

Lake Ontario open waters from the Niagara River to Hamlin Beach-

1003 AM EDT Sat Jul 18 2026



.REST OF TODAY...Southwest winds 15 to 20 knots. A chance of

showers and thunderstorms late this morning, then showers with a

chance of thunderstorms this afternoon. Some thunderstorms may

produce gusty winds this afternoon. Waves 2 to 4 feet building to

3 to 5 feet. 

.TONIGHT...West winds 15 to 20 knots becoming north 10 to

15 knots. Waves 3 to 5 feet subsiding to 2 to 4 feet. 

.SUNDAY...North winds 5 to 15 knots becoming west. Waves 1 to

3 feet subsiding to 1 foot or less. 

.SUNDAY NIGHT...West winds 10 knots or less. Waves 1 foot or

less. 

.MONDAY...Southwest winds 10 knots or less becoming south 10 to

15 knots. A chance of showers Monday night. Waves 2 feet or less.

.TUESDAY...South winds 15 to 20 knots becoming west. Showers with

a chance of thunderstorms. Waves 2 to 4 feet. 

.WEDNESDAY...West winds 15 to 20 knots becoming northwest. A

chance of showers. Waves 3 to 5 feet. 



Winds and waves higher in and near thunderstorms.



$$



LOZ063>065-182100-

Lake Ontario open waters from Hamlin Beach to the Saint Lawrence

River-

1003 AM EDT Sat Jul 18 2026



.REST OF TODAY...Southwest winds 15 to 20 knots. Areas of smoke.

Showers with a chance of thunderstorms. Some thunderstorms may

produce gusty winds this afternoon. Waves 2 to 4 feet building to

3 to 5 feet. 

.TONIGHT...West winds 15 to 20 knots becoming north. A chance of

showers and thunderstorms early. Some thunderstorms may produce

gusty winds early. Waves 3 to 6 feet. 

.SUNDAY...North winds 15 to 20 knots becoming west 5 to 15 knots.

Waves 2 to 4 feet subsiding to 1 to 2 feet. 

.SUNDAY NIGHT...West winds 5 to 15 knots. Waves 1 to 2 feet. 

.MONDAY...Southwest winds 5 to 15 knots becoming south and

increasing to 15 to 25 knots. A chance of showers Monday night.

Waves 1 foot or less building to 3 to 5 feet. 

.TUESDAY...South winds 15 to 25 knots becoming west. Showers with

a chance of thunderstorms. Waves 3 to 6 feet subsiding to 3 to

5 feet. 

.WEDNESDAY...West winds 15 to 20 knots. A chance of showers and

thunderstorms. Waves 3 to 6 feet. 



Winds and waves higher in and near thunderstorms.



$$



LOZ061-182100-

MAFOR 1815/

ONTARIO WEST 1/2 12526 11620 11720 12820 12810. A chance of

thunderstorms this afternoon. Waves 2 to 4 feet building to 3 to

5 feet this afternoon. Waves 3 to 5 feet subsiding to 2 to 4 feet

tonight. Waves 1 to 3 feet Sunday morning. 



ONTARIO EAST 1/2 12526 12620 13820 11810. A chance of

thunderstorms this afternoon. Waves 2 to 4 feet building to 3 to

5 feet this afternoon. Waves 3 to 6 feet tonight. Waves 2 to 4

feet Sunday morning. 



$$