649
FZUS61 KBUF 180803
GLFLO

Open Lake Forecast for Lake Ontario
National Weather Service Buffalo NY
403 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 30.0 inch ridge of high pressure will slide east of the Lake this
evening to the Atlantic shoreline and in its wake a warm front will
lift northeastward across the Lake tonight through tomorrow morning.
Following this warm front a cold front will slice across the Lake
Saturday afternoon and evening with this front attached to a 29.4
inch area of low pressure crossing southern 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 another cold front Tuesday
night with this front attached to a 29.5 inch area of low pressure
near James Bay. A secondary cold front will cross the Lake
Wednesday.

LOZ062-181500-
Lake Ontario open waters from the Niagara River to Hamlin Beach-
403 AM EDT Sat Jul 18 2026

.TODAY...Southwest winds 15 to 20 knots. Patchy smoke early. A
chance of showers and thunderstorms this morning, then showers
with a chance of thunderstorms this afternoon. Some thunderstorms
may produce gusty winds this afternoon. Waves 1 to 3 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>065-181500-
Lake Ontario open waters from Hamlin Beach to the Saint Lawrence
River-
403 AM EDT Sat Jul 18 2026

.TODAY...South winds 15 to 20 knots becoming southwest. Showers
likely early, then showers with a chance of thunderstorms from
late morning on. Areas of smoke. Some thunderstorms may produce
gusty winds this afternoon. Waves 1 to 3 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.

$$

LOZ061-181500-
MAFOR 1809/
ONTARIO WEST 1/2 11410 11520 12526 11620 11720 12820. A chance of
thunderstorms today. Waves 1 to 3 feet building to 3 to 5 feet
today. Waves 3 to 5 feet subsiding to 2 to 4 feet tonight.

ONTARIO EAST 1/2 11420 11426 12526 12620 12820. A chance of
thunderstorms today. Waves 1 to 3 feet building to 3 to 5 feet
today. Waves 3 to 6 feet tonight.

$$