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open lake forecast for lake ontario
national weather service buffalo ny
1002 am 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 30.5 inch surface high will drift along the northeast 
coast to the canadian maritimes through tonight. a surface low will 
cut northeastward through the central great lakes sunday, slowly 
deepening from 29.6 inches sunday morning to 29.4 inches sunday 
night over western quebec. a cold front from this low will cross the 
lake late sunday night. 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 29.7 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.


loz062-302200-
lake ontario open waters from the niagara river to hamlin beach-
1002 am est sun nov 30 2025

...gale warning in effect through late tonight...

.this afternoon...south winds to 30 knots becoming southwest and
increasing to 35 knot gales. rain. waves 4 to
7 feet building to 10 to 13 feet. waves occasionally around
16 feet. 
.tonight...southwest gales to 35 knots becoming northwest and
diminishing to 30 knots after midnight. a chance of rain and snow
showers through the early overnight. waves 11 to 15 feet
subsiding to 6 to 9 feet. waves occasionally around 19 feet. 
.monday...northwest winds 15 to 20 knots becoming southwest 5 to
15 knots. waves 4 to 7 feet subsiding to 1 foot or less. waves
occasionally around 9 feet. 
.monday night...southwest winds 5 to 15 knots becoming south.
snow showers overnight. waves 2 feet or less. 
.tuesday...southwest winds 5 to 15 knots becoming west. snow
showers during the day. waves 2 feet or less. 
.wednesday...southwest winds 15 to 25 knots becoming west to
30 knots. snow showers likely wednesday night. waves 3 to 5 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 6 to 10 feet subsiding to 2 to 4 feet.
waves occasionally around 13 feet. 

$$
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glflo 
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open lake forecast for lake ontario
national weather service buffalo ny
1002 am 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 30.5 inch surface high will drift along the northeast 
coast to the canadian maritimes through tonight. a surface low will 
cut northeastward through the central great lakes sunday, slowly 
deepening from 29.6 inches sunday morning to 29.4 inches sunday 
night over western quebec. a cold front from this low will cross the 
lake late sunday night. 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 29.7 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.


loz063-302200-
lake ontario open waters from hamlin beach to sodus bay-
1002 am est sun nov 30 2025

...gale warning in effect through late tonight...

.this afternoon...south winds to 30 knots becoming southwest and
increasing to 35 knot gales. rain, then rain
showers likely late. waves 6 to 10 feet building to 9 to 12 feet.
waves occasionally around 15 feet. 
.tonight...southwest gales to 35 knots becoming northwest and
diminishing to 30 knots after midnight. a chance of rain and snow
showers through the early overnight, then a chance of snow
showers late. waves 11 to 16 feet subsiding to 9 to 12 feet.
waves occasionally around 20 feet. 
.monday...northwest winds 15 to 25 knots becoming west and
diminishing to 5 to 15 knots. waves 7 to 10 feet subsiding to
1 to 3 feet. waves occasionally around 13 feet. 
.monday night...south winds 5 to 15 knots increasing to 15 to
20 knots. snow showers likely overnight. waves 1 to 3 feet. 
.tuesday...south winds 15 to 20 knots becoming west 5 to
15 knots. snow showers likely during the day, then a chance of
snow showers tuesday night. waves 1 to 3 feet. 
.wednesday...southwest winds 15 to 25 knots increasing to
30 knots. snow showers likely wednesday night. waves 2 to 4 feet
building to 8 to 11 feet. waves occasionally around 14 feet. 
.thursday...west gales to 35 knots becoming northwest and
diminishing to 15 to 20 knots. snow showers likely during the
day, then a chance of snow showers thursday night. waves 8 to
12 feet subsiding to 3 to 6 feet. waves occasionally around
15 feet. 

$$
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glflo 
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open lake forecast for lake ontario
national weather service buffalo ny
1002 am 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 30.5 inch surface high will drift along the northeast 
coast to the canadian maritimes through tonight. a surface low will 
cut northeastward through the central great lakes sunday, slowly 
deepening from 29.6 inches sunday morning to 29.4 inches sunday 
night over western quebec. a cold front from this low will cross the 
lake late sunday night. 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 29.7 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.


loz064-065-302200-
lake ontario open waters from sodus bay to the saint lawrence
river-
1002 am est sun nov 30 2025

...gale warning in effect through late tonight...

.this afternoon...south winds to 30 knots becoming southwest and
increasing to 40 knot gales. rain. waves 7 to
11 feet building to 9 to 12 feet. waves occasionally around
15 feet. 
.tonight...southwest gales to 35 knots becoming northwest and
diminishing to 30 knots after midnight. rain showers early, then
rain and snow showers. a chance of snow and rain showers late.
waves 10 to 14 feet building to 12 to 16 feet, then subsiding to
10 to 13 feet. waves occasionally around 20 feet. 
.monday...northwest winds 15 to 25 knots becoming west and
diminishing to 5 to 15 knots. a chance of snow showers in the
morning. waves 7 to 10 feet subsiding to 1 to 3 feet. waves
occasionally around 13 feet. 
.monday night...southwest winds 10 knots or less becoming south
and increasing to 15 to 20 knots overnight. snow showers likely
overnight. waves 1 to 3 feet. 
.tuesday...south winds 15 to 20 knots becoming northwest 5 to
15 knots. snow showers during the day, then a chance of snow
showers tuesday night. waves 2 to 4 feet subsiding to 1 to
3 feet. 
.wednesday...west winds 15 to 20 knots becoming southwest and
increasing to 30 knots. a chance of snow showers during the day,
then snow showers wednesday night. waves 2 to 4 feet building to
8 to 11 feet. waves occasionally around 14 feet. 
.thursday...northwest gales to 35 knots diminishing to 15 to
20 knots. snow showers during the day, then a chance of snow
showers thursday night. waves 8 to 12 feet subsiding to 3 to
6 feet. waves occasionally around 15 feet. 

$$
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forecast for the saint lawrence river
including the thousand islands region
national weather service buffalo ny
1002 am est sun nov 30 2025


slz022-302200-
saint lawrence river from cape vincent to ogdensburg-
1002 am est sun nov 30 2025

...small craft advisory in effect through late tonight...

.rest of today...south winds 15 to 25 knots. snow and rain, then
rain late. 
.tonight...southwest winds 15 to 25 knots becoming northwest.
rain and snow showers through the early overnight, then a chance
of snow showers late. 
.monday...northwest winds 5 to 15 knots becoming southwest less
than 10 knots. a chance of snow showers in the morning. 
.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 west. snow
showers during the day. 
.wednesday...southwest winds 5 to 10 knots increasing to 15 to
20 knots. a chance of snow showers during the day, then snow
showers wednesday night. 
.thursday...west winds 15 to 20 knots diminishing to 5 to
15 knots. snow showers during the day, then a chance of snow
showers thursday night. 

$$
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