242
FZUS61 KBUF 202003
GLFLO

Open Lake Forecast for Lake Ontario
National Weather Service Buffalo NY
403 PM EDT Mon Jul 20 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 area of high pressure will build across the Great Lakes
this evening, followed by a warm front crossing the lake late
tonight 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.

LOZ062-210300-
Lake Ontario open waters from the Niagara River to Hamlin Beach-
403 PM EDT Mon Jul 20 2026

.TONIGHT...Southeast winds 5 to 15 knots becoming south. Waves
2 feet or less.
.TUESDAY...South winds 15 to 25 knots becoming southwest. A
chance of showers early, then showers with a chance of
thunderstorms late in the morning. Showers with thunderstorms
likely in the afternoon. Some thunderstorms may produce gusty
winds in the afternoon. Waves 1 to 3 feet building to 3 to
6 feet.
.TUESDAY NIGHT...Southwest winds 15 to 20 knots becoming west.
Showers with thunderstorms likely in the evening, then a chance
of showers overnight. Some thunderstorms may produce gusty winds
in the evening. Waves 3 to 5 feet.
.WEDNESDAY...West winds 15 to 25 knots. Waves 3 to 6 feet
building to 4 to 7 feet. Waves occasionally around 9 feet.
.WEDNESDAY NIGHT...Northwest winds 15 to 25 knots becoming west
and diminishing to 10 to 15 knots. Waves 4 to 7 feet subsiding to
2 to 4 feet. Waves occasionally around 9 feet.
.THURSDAY...West winds 5 to 15 knots becoming southwest. Waves
1 to 3 feet subsiding to 1 foot or less.
.FRIDAY...Southwest winds 10 knots or less becoming south. Waves
1 foot or less.
.SATURDAY...Southwest winds 10 knots or less. Waves 1 foot or
less.

Winds and waves higher in and near thunderstorms.

$$

LOZ063>065-210300-
Lake Ontario open waters from Hamlin Beach to the Saint Lawrence
River-
403 PM EDT Mon Jul 20 2026

.TONIGHT...East winds 5 to 15 knots becoming south 15 to
20 knots. Waves 2 feet or less building to 2 to 4 feet.
.TUESDAY...South winds 15 to 20 knots becoming southwest. A
chance of showers and thunderstorms late in the morning. Showers
with thunderstorms likely in the afternoon. Some thunderstorms
may produce gusty winds in the afternoon. Waves 2 to 4 feet
building to 3 to 5 feet.
.TUESDAY NIGHT...South winds 15 to 20 knots becoming west.
Showers likely with a chance of thunderstorms in the evening,
then showers likely overnight. Some thunderstorms may produce
gusty winds in the evening. Waves 2 to 4 feet building to 3 to
6 feet.
.WEDNESDAY...West winds 20 to 25 knots. A chance of showers in
the morning. Waves 5 to 8 feet building to 6 to 9 feet. Waves
occasionally around 11 feet.
.WEDNESDAY NIGHT...West winds 15 to 25 knots becoming northwest.
Waves 5 to 9 feet subsiding to 3 to 6 feet. Waves occasionally
around 11 feet.
.THURSDAY...West winds 15 to 20 knots becoming southwest 5 to
15 knots. Waves 3 to 5 feet subsiding to 1 to 3 feet.
.FRIDAY...Southwest winds 10 knots or less becoming south. Waves
1 foot or less.
.SATURDAY...South winds 10 knots or less. Waves 1 foot or less.

Winds and waves higher in and near thunderstorms.

$$

LOZ061-210300-
MAFOR 2021/
ONTARIO WEST 1/2 12300 11400 12410 11420 11539 11536. Waves 2
feet or less tonight. Waves 1 to 3 feet building to 3 to 6 feet
Tuesday.

ONTARIO EAST 1/2 11100 11300 11410 14420 11529. Waves 2 feet or
less building to 2 to 4 feet tonight. Waves 2 to 4 feet building
to 3 to 5 feet Tuesday.

$$