fzus63 kmqt 181956
glfls 
expires:202608190800;;952665

open lake forecast for lake superior
national weather service marquette mi
356 pm edt tue aug 18 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 29.6 inch low remains over hudson bay through wednesday before 
shifting east to northern quebec. this extends troughing of 29.8 
inches over lake superior through early this evening, then weak 29.9 
inch ridging returns to the lake by wednesday morning. a 30.0 inch 
high pressure settles over the northern plains today and tonight, 
eventually moving over lake superior wednesday afternoon 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 30.1 inch 
ridging for the latter part of the weekend into next week.




lsz162-190800-
lake superior west of a line from saxon harbor wi to grand
portage mn beyond 5nm-
356 pm edt tue aug 18 2026 /256 pm cdt tue aug 18 2026/

.late this afternoon...southwest winds 10 to 20 knots. waves calm
to 2 feet building to 1 to 3 feet. 
.tonight...west winds 5 to 15 knots. waves subsiding to calm to
2 feet. 
.wednesday...west winds 5 to 15 knots backing southwest in the
afternoon. waves calm to 2 feet. 
.wednesday night...southwest winds 5 to 15 knots backing
northeast after midnight. waves calm to 2 feet. 
.thursday...east winds 5 to 15 knots. a chance of showers. a
slight chance of thunderstorms by mid afternoon. waves calm to
2 feet. 
.thursday night...east winds 5 to 15 knots backing northeast
after midnight. a chance of showers. waves calm to 2 feet. 
.friday...northeast winds 5 to 15 knots backing north by mid
afternoon. waves calm to 2 feet. 
.friday night...west winds 5 to 15 knots veering northwest after
midnight. waves calm to 2 feet. 
.saturday...northwest winds 5 to 15 knots veering north. waves
calm to 2 feet. 
.sunday...east winds 5 to 15 knots. waves calm to 2 feet. 

$$

fzus63 kmqt 181956
glfls 
expires:202608190800;;952666

open lake forecast for lake superior
national weather service marquette mi
356 pm edt tue aug 18 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 29.6 inch low remains over hudson bay through wednesday before 
shifting east to northern quebec. this extends troughing of 29.8 
inches over lake superior through early this evening, then weak 29.9 
inch ridging returns to the lake by wednesday morning. a 30.0 inch 
high pressure settles over the northern plains today and tonight, 
eventually moving over lake superior wednesday afternoon 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 30.1 inch 
ridging for the latter part of the weekend into next week.




lsz263-190800-
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-
356 pm edt tue aug 18 2026

.late this afternoon...southwest winds 15 to 25 knots. waves 1 to
3 feet. 
.tonight...west winds 10 to 20 knots diminishing to 5 to 15 knots
after midnight, then veering northwest late. waves subsiding to
calm to 2 feet. 
.wednesday...northwest winds 5 to 15 knots backing southwest
late. 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...south winds less than 10 knots becoming southeast
5 to 15 knots by mid afternoon. a slight chance of showers. a
slight chance of thunderstorms by mid afternoon. waves calm to
2 feet. 
.thursday night...southeast winds 5 to 15 knots backing east
after midnight. a chance of showers. waves calm to 2 feet. 
.friday...northeast winds 5 to 15 knots backing north by mid
afternoon. waves calm to 2 feet. 
.friday night...west winds 5 to 15 knots veering northwest after
midnight. waves calm to 2 feet. 
.saturday...northwest winds 5 to 15 knots veering north. waves
calm to 2 feet. 
.sunday...north winds 5 to 15 knots veering southeast. waves calm
to 2 feet. 

$$