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forecast for the saint lawrence river
including the thousand islands region
national weather service buffalo ny
404 am edt tue apr 21 2026


slz022-024-211500-
saint lawrence river from cape vincent to saint regis
404 am edt tue apr 21 2026

.today...south winds 5 to 15 knots becoming southwest. partly
sunny. 
.tonight...south winds 5 to 15 knots becoming southeast. a chance
of rain showers late in the evening. 
.wednesday...east winds less than 10 knots becoming north. partly
to mostly sunny. 
.wednesday night...northeast winds less than 10 knots. partly
cloudy. 
.thursday...northwest winds 10 knots or less becoming north.
partly cloudy. 
.friday...north winds 10 knots or less becoming northeast. mainly
clear. 
.saturday...northeast winds 10 knots or less becoming east. a
chance of rain showers. 

$$
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glflo 
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open lake forecast for lake ontario
national weather service buffalo ny
403 am edt tue apr 21 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 30.4 inch high will settle southeast across the great 
lakes tonight, before sliding off the mid-atlantic coast tuesday. a 
29.4 inch low over lower hudson bay tuesday, will weaken to 29.9 
inches by wednesday, while pushing a cold front across the lake 
tuesday night. a 30.2 inch high will then build across the great 
lakes region wednesday and thursday. a warm front will approach the 
lake by friday. a 29.6 inch low may move southwest of the lake on 
saturday.


loz062-211500-
lake ontario open waters from the niagara river to hamlin beach-
403 am edt tue apr 21 2026

.today...south winds 5 to 15 knots becoming southeast. waves
2 feet or less. 
.tonight...southeast winds 5 to 15 knots becoming northeast. a
chance of rain showers after midnight. waves 1 to 3 feet. 
.wednesday...north winds less than 10 knots. waves 2 feet or
less. 
.wednesday night...west winds less than 10 knots becoming
northwest. waves 1 foot or less. 
.thursday...north winds 10 knots or less becoming northeast.
waves 1 foot or less. 
.friday...east winds 10 to 15 knots increasing to 15 to 20 knots.
a chance of showers friday night. waves 1 to 3 feet building to
3 to 5 feet. 
.saturday...east winds 15 to 20 knots becoming northeast 10 to
15 knots. showers likely. waves 3 to 5 feet. 

$$
fzus61 kbuf 210803
glflo 
expires:202604211500;;734547

open lake forecast for lake ontario
national weather service buffalo ny
403 am edt tue apr 21 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 30.4 inch high will settle southeast across the great 
lakes tonight, before sliding off the mid-atlantic coast tuesday. a 
29.4 inch low over lower hudson bay tuesday, will weaken to 29.9 
inches by wednesday, while pushing a cold front across the lake 
tuesday night. a 30.2 inch high will then build across the great 
lakes region wednesday and thursday. a warm front will approach the 
lake by friday. a 29.6 inch low may move southwest of the lake on 
saturday.


loz063>065-211500-
lake ontario open waters from hamlin beach to the saint lawrence
river-
403 am edt tue apr 21 2026

.today...south winds 5 to 15 knots becoming southeast. waves 1 to
3 feet. 
.tonight...southeast winds 10 to 15 knots becoming south and
increasing to 15 to 25 knots. a chance of showers from late
evening on. waves 1 to 3 feet building to 3 to 5 feet, then
subsiding to 2 to 4 feet. 
.wednesday...east winds 10 knots or less becoming north. waves
2 feet or less. 
.wednesday night...northwest winds less than 10 knots. waves
1 foot or less. 
.thursday...northwest winds 10 knots or less becoming northeast.
waves 1 foot or less. 
.friday...northeast winds 5 to 15 knots becoming east 15 to
20 knots. a chance of rain showers friday night. waves 2 feet or
less building to 2 to 4 feet. 
.saturday...east winds 15 to 20 knots. showers likely. waves 3 to
5 feet subsiding to 2 to 4 feet. 

$$
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