fzus63 kmqt 220201
glfls 
expires:202607220800;;382405

open lake forecast for lake superior
national weather service marquette mi
1001 pm edt tue jul 21 2026

for waters beyond 5 nautical miles of shore on lake superior.

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... 

heights continue to rise over the lake tonight as a 29.3 inch low 
pressure east of james bay continues to track through northern 
quebec and ridging over the northern plains expands eastward. the 
ridge over lake superior becomes maximized at 30.1 inches over the 
western lake on wednesday before the high flattens and moves east 
towards new england thursday into friday morning. while ridging of 
around 30.0 inches looks to remain over lake superior on thursday, a 
weak 29.9 to 30.0 inch low could move over the northwestern half of 
the lake by thursday night into friday morning. as a low around 29.3 
inches lifts from far northern ontario into hudson bay friday night 
into saturday morning, expect troughing of around 29.8 inches to 
move into lake superior in response by saturday morning. troughing 
of at least 29.8 inches looks to remain over the lake for the rest 
of the day. 




lsz263-220800-
lake superior from saxon harbor wi to upper entrance to portage
canal mi 5nm off shore to the us/canadian border including isle
royale national park-
1001 pm edt tue jul 21 2026

.rest of tonight...northwest winds 5 to 15 knots. waves calm to
2 feet. 
.wednesday...northwest winds 5 to 15 knots backing west in the
afternoon, then becoming southwest 10 to 20 knots late. waves
building to 1 to 3 feet. 
.wednesday night...southwest winds 10 to 20 knots becoming west
5 to 15 knots after midnight, then increasing to 10 to 20 knots
late. waves subsiding to calm to 2 feet, then building to 1 to
3 feet. 
.thursday...southwest winds 15 to 25 knots. waves building to
2 to 4 feet. 
.thursday night...southwest winds 10 to 20 knots increasing to
15 to 25 knots after midnight. a slight chance of showers and
thunderstorms. waves subsiding to calm to 2 feet, then building
to 2 to 4 feet. 
.friday...southwest winds 20 to 30 knots. waves building to 3 to
6 feet occasionally to 8 feet. 
.friday night...southwest winds 20 to 30 knots increasing to
gales to 35 knots after midnight. a chance of showers after
midnight. waves subsiding to 2 to 4 feet, then building to 4 to
7 feet occasionally to 9 feet. 
.saturday...southwest gales to 35 knots becoming north 5 to
15 knots. a chance of showers. waves subsiding to calm to 2 feet.
.sunday...east winds 5 to 15 knots. a chance of showers. waves
calm to 2 feet. 

$$

fzus63 kmqt 220201
glfls 
expires:202607220800;;382404

open lake forecast for lake superior
national weather service marquette mi
1001 pm edt tue jul 21 2026

for waters beyond 5 nautical miles of shore on lake superior.

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... 

heights continue to rise over the lake tonight as a 29.3 inch low 
pressure east of james bay continues to track through northern 
quebec and ridging over the northern plains expands eastward. the 
ridge over lake superior becomes maximized at 30.1 inches over the 
western lake on wednesday before the high flattens and moves east 
towards new england thursday into friday morning. while ridging of 
around 30.0 inches looks to remain over lake superior on thursday, a 
weak 29.9 to 30.0 inch low could move over the northwestern half of 
the lake by thursday night into friday morning. as a low around 29.3 
inches lifts from far northern ontario into hudson bay friday night 
into saturday morning, expect troughing of around 29.8 inches to 
move into lake superior in response by saturday morning. troughing 
of at least 29.8 inches looks to remain over the lake for the rest 
of the day. 




lsz162-220800-
lake superior west of a line from saxon harbor wi to grand
portage mn beyond 5nm-
1001 pm edt tue jul 21 2026 /901 pm cdt tue jul 21 2026/

.rest of tonight...northwest winds 10 to 20 knots. waves calm to
2 feet. 
.wednesday...west winds 5 to 15 knots backing southwest in the
afternoon, then increasing to 10 to 20 knots late. waves building
to 1 to 3 feet. 
.wednesday night...southwest winds 5 to 15 knots. waves subsiding
to calm to 2 feet. 
.thursday...southwest winds 10 to 20 knots. waves building to
1 to 3 feet. 
.thursday night...southwest winds 10 to 20 knots. a slight chance
of thunderstorms through midnight. a slight chance of showers.
waves subsiding to calm to 2 feet. 
.friday...southwest winds 15 to 25 knots increasing to 20 to
30 knots by mid afternoon. waves building to 3 to 5 feet
occasionally to 7 feet, then subsiding to 2 to 4 feet. 
.friday night...southwest winds 20 to 30 knots increasing to
gales to 35 knots after midnight. a chance of showers. waves
building to 3 to 6 feet occasionally to 8 feet. 
.saturday...southwest winds 20 to 30 knots becoming north 5 to
15 knots. a chance of showers. waves subsiding to calm to 2 feet.
.sunday...east winds 5 to 15 knots backing northeast. waves calm
to 2 feet. 

$$