fzus63 kmqt 180801
glfls 
expires:202509182000;;179683

open lake forecast for lake superior
national weather service marquette mi
401 am edt thu sep 18 2025

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 30.3 inch high over manitoba shifts over northern ontario through 
friday and strengthens to 30.4 inches on saturday over eastern 
ontario and western quebec. the 30.4 inch high will move to new 
england by sunday morning. this brings 30.2 inch ridging back over 
lake superior late today and friday, weakening to 30.1 inches by the 
end of the day saturday. troughing then begins to spread over lake 
superior sunday into the beginning of next week as low pressure 
deepens over the canadian prairie to around 29.5 inches.



lsz162-182000-
lake superior west of a line from saxon harbor wi to grand
portage mn beyond 5nm-
401 am edt thu sep 18 2025 /301 am cdt thu sep 18 2025/

.early this morning...northeast winds 15 to 25 knots. waves 1 to
3 feet. 
.today...northeast winds 15 to 25 knots increasing to 20 to
30 knots in the afternoon, then becoming east 15 to 25 knots
late. a slight chance of showers. waves building to 3 to 6 feet
occasionally to 8 feet. 
.tonight...east winds 15 to 25 knots. a slight chance of showers
and thunderstorms. waves subsiding to 3 to 5 feet occasionally to
7 feet. 
.friday...east winds 15 to 25 knots increasing to 20 to 30 knots
in the afternoon. a slight chance of thunderstorms through early
afternoon. a chance of showers. waves building to 5 to 8 feet
occasionally to 10 feet. 
.friday night...east winds 20 to 30 knots diminishing to 10 to
20 knots after midnight. a chance of showers and a slight chance
of thunderstorms. waves subsiding to 2 to 4 feet. 
.saturday...east winds 10 to 20 knots. showers likely. waves
subsiding to calm to 2 feet. 
.saturday night...southeast winds 5 to 15 knots veering south
after midnight. showers likely through midnight. a chance of
thunderstorms. a chance of showers after midnight. waves calm to
2 feet. 
.sunday...south winds 5 to 15 knots backing northeast. a chance
of showers. waves calm to 2 feet. 
.monday...south winds 5 to 15 knots backing north. waves calm to
2 feet. 

$$