fzus63 kmqt 170801
glfls 
expires:202608172000;;336431

open lake forecast for lake superior
national weather service marquette mi
401 am edt mon aug 17 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...

a 30.1 inch high pressure expands over the midwest this morning, 
extending a 30.0 inch ridge over lake superior. this high weakens to 
30.0 inches throughout today and shifts south as a 29.8 inch trough, 
associated with a 29.6 inch low over the hudson bay, deepens over 
lake superior. troughing lingers until tuesday afternoon when weak 
29.9 inch ridging returns to lake superior. 30.0 inch high pressure 
settles over the northern plains tuesday afternoon and night, 
eventually moving over lake superior wednesday evening before 
expanding to cover much of the great lakes by thursday afternoon. 
friday into the weekend, a low pressure of around 29.8 inches 
transits across northern ontario quickly followed by 30.2 inch 
ridging for the latter part of the weekend into next week.




lsz162-172000-
lake superior west of a line from saxon harbor wi to grand
portage mn beyond 5nm-
401 am edt mon aug 17 2026 /301 am cdt mon aug 17 2026/

.early this morning...west winds 5 to 15 knots. waves calm to
2 feet. 
.today...west winds 5 to 15 knots becoming southwest 10 to
20 knots in the afternoon. waves building to 1 to 3 feet. 
.tonight...west winds 10 to 20 knots. a chance of showers and a
slight chance of thunderstorms through midnight. waves subsiding
to calm to 2 feet. 
.tuesday...west winds 5 to 15 knots becoming southwest 10 to
20 knots late. waves calm to 2 feet. 
.tuesday night...west winds 5 to 15 knots becoming northwest
10 to 20 knots after midnight. waves calm to 2 feet. 
.wednesday...northwest winds 5 to 15 knots backing southwest by
mid afternoon. waves calm to 2 feet. 
.wednesday night...south winds 5 to 15 knots becoming north less
than 10 knots after midnight. waves calm to 2 feet. 
.thursday...south winds 5 to 15 knots veering southwest. a chance
of showers. waves calm to 2 feet. 
.friday...southwest winds 10 to 20 knots veering northwest. a
chance of showers. waves calm to 2 feet. 

$$

fzus63 kmqt 170801
glfls 
expires:202608172000;;336432

open lake forecast for lake superior
national weather service marquette mi
401 am edt mon aug 17 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...

a 30.1 inch high pressure expands over the midwest this morning, 
extending a 30.0 inch ridge over lake superior. this high weakens to 
30.0 inches throughout today and shifts south as a 29.8 inch trough, 
associated with a 29.6 inch low over the hudson bay, deepens over 
lake superior. troughing lingers until tuesday afternoon when weak 
29.9 inch ridging returns to lake superior. 30.0 inch high pressure 
settles over the northern plains tuesday afternoon and night, 
eventually moving over lake superior wednesday evening before 
expanding to cover much of the great lakes by thursday afternoon. 
friday into the weekend, a low pressure of around 29.8 inches 
transits across northern ontario quickly followed by 30.2 inch 
ridging for the latter part of the weekend into next week.




lsz263-172000-
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-
401 am edt mon aug 17 2026

.early this morning...west winds 5 to 15 knots. waves calm to
2 feet. 
.today...west winds 5 to 15 knots becoming southwest 15 to
25 knots in the afternoon. waves building to 2 to 4 feet. 
.tonight...southwest winds 15 to 25 knots becoming west 10 to
20 knots after midnight. a slight chance of thunderstorms through
midnight. a slight chance of showers. waves subsiding to calm to
2 feet. 
.tuesday...northwest winds 10 to 20 knots backing southwest late.
waves building to 1 to 3 feet. 
.tuesday night...west winds 10 to 20 knots becoming northwest
5 to 15 knots after midnight. waves subsiding to calm to 2 feet. 
.wednesday...northwest winds 5 to 15 knots backing southwest by
mid afternoon. waves calm to 2 feet. 
.wednesday night...southwest winds 5 to 15 knots becoming south
less than 10 knots after midnight. waves calm to 2 feet. 
.thursday...southwest winds 10 to 20 knots backing south. a
chance of showers. waves calm to 2 feet. 
.friday...southwest winds 10 to 20 knots becoming west 5 to
15 knots. a chance of showers. waves building to 1 to 3 feet,
then subsiding to calm to 2 feet. 

$$