Great Lakes Forecast
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421
FZUS61 KBUF 190207
GLFLO

Open Lake Forecast for Lake Ontario
National Weather Service Buffalo NY
1007 PM EDT Fri Sep 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 ridge averaging 30.4 inches affects the lake through
Sunday as the parent high pressure center moves from near James Bay
to the Canadian Maritimes. During Sunday night, a cold front should
sweep southward across the lake. Behind the front, a ridge averaging
30.4 inches should build from northern Ontario through Monday. By
Monday night through Tuesday, a low of 30.0 inches should move from
near the Lower Ohio Valley toward the Mid-Atlantic States and extend
a weak trough averaging 30.3 inches over the eastern Great Lakes.

LOZ062-190915-
Lake Ontario open waters from the Niagara River to Hamlin Beach-
1007 PM EDT Fri Sep 18 2026

.OVERNIGHT...Northeast winds 10 to 15 knots becoming east
15 to 20 knots. Waves 1 to 2 feet building to 3 to 5 feet.
.SATURDAY...East winds 15 to 20 knots diminishing to 10 to
15 knots. Waves 2 to 4 feet.
.SATURDAY NIGHT...East winds 10 to 15 knots. A chance of showers
overnight. Waves 1 to 3 feet.
.SUNDAY...East winds 10 to 15 knots becoming northeast. A chance
of showers. Waves 1 to 3 feet.
.SUNDAY NIGHT...Northeast winds 10 to 15 knots increasing to
15 to 25 knots. Waves 1 to 3 feet building to 3 to 5 feet.
.MONDAY...Northeast winds 15 to 25 knots increasing to 30 knots.
Waves 3 to 6 feet building to 6 to 9 feet. Waves occasionally
around 11 feet.
.TUESDAY...East winds to 30 knots. A chance of showers Tuesday
night. Waves 6 to 9 feet. Waves occasionally around 11 feet.
.WEDNESDAY...East winds 15 to 25 knots. A chance of showers.
Waves 4 to 7 feet subsiding to 3 to 6 feet. Waves occasionally
around 9 feet.

$$

LOZ063>065-190915-
Lake Ontario open waters from Hamlin Beach to the Saint Lawrence
River-
1007 PM EDT Fri Sep 18 2026

.OVERNIGHT...Northeast winds 15 to 20 knots. Waves 1 to
3 feet building to 2 to 4 feet.
.SATURDAY...Northeast winds 5 to 15 knots. Waves 2 to 4 feet
subsiding to 1 to 3 feet.
.SATURDAY NIGHT...East winds 5 to 10 knots becoming southeast. A
chance of showers overnight. Waves 2 feet or less.
.SUNDAY...Southeast winds 10 to 15 knots becoming northeast.
Showers likely. Waves 1 to 3 feet.
.SUNDAY NIGHT...Northeast winds 15 to 25 knots. A chance of
showers in the evening. Waves 2 to 4 feet building to 3 to
5 feet.
.MONDAY...Northeast winds 15 to 25 knots. Waves 4 to 7 feet
building to 5 to 8 feet. Waves occasionally around 10 feet.
.TUESDAY...East winds 15 to 25 knots. Waves 5 to 8 feet subsiding
to 3 to 6 feet. Waves occasionally around 10 feet.
.WEDNESDAY...East winds 15 to 20 knots becoming southeast. A
chance of showers. Waves 3 to 6 feet subsiding to 2 to 4 feet.

$$

LOZ061-190915-
MAFOR 1903/
ONTARIO WEST 1/2 11120 12220 14210 11210. Waves 2 to 4 feet
building to 3 to 5 feet overnight. Waves 2 to 4 feet subsiding to
1 to 3 feet Saturday. Waves 1 to 3 feet Saturday evening.

ONTARIO EAST 1/2 11120 13110 13100 11200. Waves 1 to 3 feet
building to 2 to 4 feet overnight. Waves 2 to 4 feet subsiding to
1 to 3 feet Saturday. Waves 1 foot or less Saturday evening.

$$