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open lake forecast for lake ontario
national weather service buffalo ny
402 pm est sun nov 30 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...a 29.7 inch surface low north of lake ontario will 
track towards eastern quebec and the canadian maritimes through 
tonight, causing a cold front to cross the lake. a 30.4 inch surface 
high centered over the central plains will then build east across 
the great lakes monday, sliding quickly to new england on tuesday. a 
29.6 inch surface low off the carolina coastline tuesday morning 
will deepen to 28.9 inches over southern atlantic canada by early 
wednesday morning before going out to sea. a 30.2 inch surface high 
will build across the ohio valley and lower great lakes later 
wednesday into thursday morning before pushing off the coast. a 
large 29.2 inch surface low near hudson bay will push its cold front 
across the lake on thursday, with another 30.4 inch high building in 
its wake thursday night. the high will then quickly move east of the 
lake friday.


loz062-010400-
lake ontario open waters from the niagara river to hamlin beach-
402 pm est sun nov 30 2025

...gale warning in effect until 4 am est monday...

.tonight...southwest gales to 35 knots becoming northwest and
diminishing to 30 knots after midnight. a chance of rain showers
early, then a chance of rain and snow showers late this evening.
a chance of snow showers after midnight. waves 10 to 15 feet
subsiding to 7 to 10 feet. waves occasionally around 19 feet. 
.monday...northwest winds 15 to 20 knots becoming southwest and
diminishing to less than 10 knots in the afternoon. waves 4 to
7 feet subsiding to 2 feet or less. waves occasionally around
9 feet. 
.monday night...south winds 10 knots or less. snow overnight.
waves 1 foot or less. 
.tuesday...southeast winds 5 to 10 knots becoming northwest. snow
in the morning, then a chance of snow showers in the afternoon.
waves 1 foot or less. 
.tuesday night...northwest winds 10 to 15 knots becoming west.
waves 1 to 2 feet. 
.wednesday...southwest winds 15 to 25 knots becoming west to
30 knots. a chance of rain and snow showers during the day, then
snow showers likely with a chance of rain showers wednesday
night. waves 3 to 6 feet building to 7 to 10 feet. waves
occasionally around 13 feet. 
.thursday...west winds to 30 knots diminishing to 10 to 15 knots.
snow showers likely during the day, then a chance of snow showers
thursday night. waves 5 to 9 feet subsiding to 3 to 5 feet. waves
occasionally around 11 feet. 
.friday...southwest winds 15 to 20 knots diminishing to 10 to
15 knots. a chance of snow showers friday night. waves 3 to
5 feet subsiding to 1 to 3 feet. 

$$
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open lake forecast for lake ontario
national weather service buffalo ny
402 pm est sun nov 30 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...a 29.7 inch surface low north of lake ontario will 
track towards eastern quebec and the canadian maritimes through 
tonight, causing a cold front to cross the lake. a 30.4 inch surface 
high centered over the central plains will then build east across 
the great lakes monday, sliding quickly to new england on tuesday. a 
29.6 inch surface low off the carolina coastline tuesday morning 
will deepen to 28.9 inches over southern atlantic canada by early 
wednesday morning before going out to sea. a 30.2 inch surface high 
will build across the ohio valley and lower great lakes later 
wednesday into thursday morning before pushing off the coast. a 
large 29.2 inch surface low near hudson bay will push its cold front 
across the lake on thursday, with another 30.4 inch high building in 
its wake thursday night. the high will then quickly move east of the 
lake friday.


loz063-010400-
lake ontario open waters from hamlin beach to sodus bay-
402 pm est sun nov 30 2025

...gale warning in effect until 4 am est monday...

.tonight...southwest gales to 35 knots becoming northwest and
diminishing to 30 knots after midnight. a chance of rain and snow
showers early, then a chance of rain showers late this evening.
waves 10 to 15 feet. waves occasionally around 19 feet. 
.monday...northwest winds 15 to 25 knots becoming west and
diminishing to 5 to 10 knots in the afternoon. waves 6 to 9 feet
subsiding to 1 to 2 feet. waves occasionally around 11 feet. 
.monday night...southwest winds 10 knots or less becoming south
10 to 15 knots. snow overnight. waves 2 feet or less. 
.tuesday...south winds 5 to 15 knots becoming north. snow in the
morning, then a chance of snow showers in the afternoon. waves
2 feet or less. 
.tuesday night...north winds 10 to 15 knots becoming west. a
chance of snow showers overnight. waves 1 to 3 feet. 
.wednesday...southwest winds 15 to 25 knots becoming west to
30 knots. a chance of snow showers during the day, then snow
showers likely with a chance of rain showers wednesday night.
waves 3 to 5 feet building to 6 to 10 feet. waves occasionally
around 13 feet. 
.thursday...west winds to 30 knots diminishing to 15 to 20 knots.
snow showers likely during the day, then a chance of snow showers
thursday night. waves 7 to 11 feet subsiding to 4 to 7 feet.
waves occasionally around 14 feet. 
.friday...southwest winds 15 to 20 knots becoming south. a chance
of snow showers friday night. waves 3 to 5 feet subsiding to 2 to
4 feet. 

$$
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open lake forecast for lake ontario
national weather service buffalo ny
402 pm est sun nov 30 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...a 29.7 inch surface low north of lake ontario will 
track towards eastern quebec and the canadian maritimes through 
tonight, causing a cold front to cross the lake. a 30.4 inch surface 
high centered over the central plains will then build east across 
the great lakes monday, sliding quickly to new england on tuesday. a 
29.6 inch surface low off the carolina coastline tuesday morning 
will deepen to 28.9 inches over southern atlantic canada by early 
wednesday morning before going out to sea. a 30.2 inch surface high 
will build across the ohio valley and lower great lakes later 
wednesday into thursday morning before pushing off the coast. a 
large 29.2 inch surface low near hudson bay will push its cold front 
across the lake on thursday, with another 30.4 inch high building in 
its wake thursday night. the high will then quickly move east of the 
lake friday.


loz064-065-010400-
lake ontario open waters from sodus bay to the saint lawrence
river-
402 pm est sun nov 30 2025

...gale warning in effect until 4 am est monday...

.tonight...southwest gales to 35 knots becoming northwest and
diminishing to 30 knots after midnight. lake effect rain showers
with a chance of lake effect snow showers this evening, then a
chance of rain and snow showers after midnight. waves 10 to
15 feet. waves occasionally around 19 feet. 
.monday...northwest winds 15 to 20 knots becoming west and
diminishing to 5 to 10 knots. waves 6 to 9 feet subsiding to
2 feet or less. waves occasionally around 11 feet. 
.monday night...southwest winds 10 knots or less becoming south
10 to 15 knots. snow overnight. waves 1 to 3 feet. 
.tuesday...southeast winds 5 to 15 knots becoming north. snow.
waves 1 to 3 feet subsiding to 1 foot or less. 
.tuesday night...north winds 5 to 15 knots becoming northwest. a
chance of snow showers. waves 2 feet or less. 
.wednesday...southwest winds 15 to 20 knots increasing to
30 knots. a chance of snow showers during the day, then snow
showers with a chance of rain showers wednesday night. waves 3 to
5 feet building to 7 to 11 feet. waves occasionally around
14 feet. 
.thursday...northwest winds to 30 knots diminishing to 15 to
20 knots. snow showers during the day, then a chance of snow
showers thursday night. waves 7 to 11 feet subsiding to 4 to
7 feet. waves occasionally around 14 feet. 
.friday...southwest winds 15 to 25 knots becoming south. a chance
of snow showers during the day, then snow showers likely friday
night. waves 3 to 6 feet. 

$$
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forecast for the saint lawrence river
including the thousand islands region
national weather service buffalo ny
402 pm est sun nov 30 2025


slz022-010400-
saint lawrence river from cape vincent to ogdensburg-
402 pm est sun nov 30 2025

...small craft advisory in effect until 4 am est monday...

.tonight...southwest winds 15 to 25 knots becoming northwest and
diminishing to 10 to 15 knots. lake effect rain and snow early,
then lake effect rain showers and lake effect snow late this
evening. a chance of snow and rain showers after midnight. 
.monday...northwest winds 5 to 15 knots becoming southwest less
than 10 knots. becoming mostly sunny. 
.monday night...light and variable winds becoming south 5 to
10 knots. a chance of snow showers overnight. 
.tuesday...southeast winds 10 knots or less becoming northeast.
snow likely. 
.tuesday night...north winds less than 10 knots. mostly cloudy. 
.wednesday...south winds 5 to 10 knots becoming southwest and
increasing to 15 to 20 knots. snow showers. 
.thursday...west winds 10 to 15 knots diminishing to less than
10 knots. snow showers during the day, then a chance of snow
showers thursday night. 
.friday...south winds 5 to 10 knots. a chance of snow showers. 

$$
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