Great Lakes Forecast
Issued by NWS

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271
FZUS61 KBUF 040802
GLFLO

Open Lake Forecast for Lake Ontario
National Weather Service Buffalo NY
402 AM EDT Fri Jul 4 2025

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...An expansive 30.1 inch high will build eastward across
the Lower Great Lakes today...before drifting to the eastern
seaboard Saturday. A wavy cold frontal boundary will then slowly
push southeastward across the Upper Great Lakes and southern Ontario
Sunday, then across the Lower Great Lakes on Monday. Following the
frontal passage...a 30.1 inch surface high will build across the
Lower Great Lakes on Tuesday.

LOZ062-041500-
Lake Ontario open waters from the Niagara River to Hamlin Beach-
402 AM EDT Fri Jul 4 2025

.TODAY...North winds 10 knots or less becoming southwest. Waves
1 foot or less.
.TONIGHT...South winds 5 to 10 knots. Waves 1 foot or less.
.SATURDAY...South winds 5 to 15 knots. Waves 2 feet or less.
.SATURDAY NIGHT...South winds 10 to 15 knots becoming southwest.
Waves 1 to 2 feet.
.SUNDAY...Southwest winds 15 to 20 knots diminishing to 10 to
15 knots. Waves 1 to 3 feet building to 2 to 4 feet, then
subsiding to 1 to 3 feet.
.MONDAY...West winds around 10 knots becoming northwest. A chance
of showers and thunderstorms. Waves 1 to 2 feet.
.TUESDAY...Northwest winds 5 to 10 knots. Waves 1 foot or less.

Winds and waves higher in and near thunderstorms.

$$

LOZ063>065-041500-
Lake Ontario open waters from Hamlin Beach to the Saint Lawrence
River-
402 AM EDT Fri Jul 4 2025

.TODAY...North winds 5 to 10 knots becoming southwest. Waves
2 feet or less.
.TONIGHT...Southwest winds 5 to 10 knots becoming south. Waves
1 foot or less.
.SATURDAY...South winds 5 to 10 knots. Waves 1 foot or less.
.SATURDAY NIGHT...South winds 5 to 15 knots. Waves 2 feet or
less.
.SUNDAY...Southwest winds 10 to 15 knots. Waves 1 to 3 feet.
.MONDAY...Southwest winds 5 to 10 knots becoming northwest. A
chance of showers and thunderstorms. Waves 1 to 3 feet.
.TUESDAY...Northwest winds 5 to 10 knots becoming west. Waves
1 foot or less.

Winds and waves higher in and near thunderstorms.

$$

LOZ061-041500-
MAFOR 0409/
ONTARIO WEST 1/2 11800 11700 11600 12500 13400. Waves 2 feet or
less.

ONTARIO EAST 1/2 11800 11700 11600 13500 12400. Waves 2 feet or
less.

$$