fzus61 kbuf 202003
glflo 
expires:202607210300;;306731

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.


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.

$$

fzus61 kbuf 202003
glfsl 
expires:202607210300;;306797

forecast for the saint lawrence river
including the thousand islands region
national weather service buffalo ny
403 pm edt mon jul 20 2026


slz022-024-210300-
saint lawrence river from cape vincent to saint regis
403 pm edt mon jul 20 2026

.tonight...southwest winds 10 knots or less becoming south 10 to
15 knots. partly to mostly cloudy. 
.tuesday...south winds 10 to 15 knots. a chance of showers late
in the morning. showers with thunderstorms likely in the
afternoon. some thunderstorms may produce gusty winds in the
afternoon. 
.tuesday night...south winds 5 to 15 knots becoming southwest.
showers with a chance of thunderstorms in the evening, then
showers overnight. 
.wednesday...southwest winds 10 to 15 knots becoming west 15 to
20 knots. a chance of showers in the morning, then showers likely
in the afternoon. 
.wednesday night...west winds 5 to 15 knots. showers likely in
the evening. 
.thursday...southwest winds 10 knots or less. becoming mainly
clear. 
.friday...southwest winds less than 10 knots. mainly clear, then
becoming partly cloudy. 
.saturday...southwest winds less than 10 knots becoming south.
mainly clear, then becoming partly cloudy. 

winds and waves higher in and near thunderstorms.

$$