fzus63 kmqt 200801
glfls 
expires:202608202000;;037840

open lake forecast for lake superior
national weather service marquette mi
400 am edt thu aug 20 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...

30.0 inch high pressure expands into the rest of the great lakes at 
30.1 inches today. a weakening shortwave low of 29.8 inches moves 
towards western lake superior today, eventually bringing 29.9 inch 
troughing back over the lake tonight. friday into this weekend, a 
low pressure of around 29.8 inches transits across northern ontario, 
reinforcing 29.9 inch troughing over lake superior friday into 
saturday morning. this is quickly followed by 30.1 inch ridging for 
the latter part of the weekend into early next week via a 30.2 inch 
parent high from canada that drops down into the ohio river valley 
by late monday.




lsz162-202000-
lake superior west of a line from saxon harbor wi to grand
portage mn beyond 5nm-
400 am edt thu aug 20 2026 /300 am cdt thu aug 20 2026/

.early this morning...south winds less than 10 knots. a slight
chance of showers. waves calm to 2 feet. 
.today...east winds 5 to 15 knots veering southeast in the
afternoon, then becoming east 10 to 20 knots late. a chance of
showers through early afternoon. a slight chance of
thunderstorms. showers by mid afternoon. waves calm to 2 feet. 
.tonight...east winds 5 to 15 knots backing northeast after
midnight. a chance of showers and a slight chance of
thunderstorms through midnight. waves calm to 2 feet. 
.friday...northeast winds 5 to 15 knots backing north in the
afternoon, then backing southwest late. waves calm to 2 feet. 
.friday night...west winds 5 to 15 knots becoming northwest 10 to
20 knots after midnight. waves calm to 2 feet. 
.saturday...northwest winds 10 to 20 knots. waves calm to 2 feet.
.saturday night...north winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. waves calm to 2 feet. 
.sunday...north winds 5 to 15 knots veering northeast. waves calm
to 2 feet. 
.monday...east winds 5 to 15 knots. waves calm to 2 feet. 

$$

fzus63 kmqt 200801
glfls 
expires:202608202000;;037841

open lake forecast for lake superior
national weather service marquette mi
400 am edt thu aug 20 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...

30.0 inch high pressure expands into the rest of the great lakes at 
30.1 inches today. a weakening shortwave low of 29.8 inches moves 
towards western lake superior today, eventually bringing 29.9 inch 
troughing back over the lake tonight. friday into this weekend, a 
low pressure of around 29.8 inches transits across northern ontario, 
reinforcing 29.9 inch troughing over lake superior friday into 
saturday morning. this is quickly followed by 30.1 inch ridging for 
the latter part of the weekend into early next week via a 30.2 inch 
parent high from canada that drops down into the ohio river valley 
by late monday.




lsz263-202000-
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-
400 am edt thu aug 20 2026

.early this morning...south winds 5 to 15 knots. patchy dense
fog. waves calm to 2 feet. 
.today...southwest winds 5 to 15 knots backing southeast in the
afternoon, then backing east late. patchy dense fog through early
afternoon. a slight chance of showers through early afternoon,
then showers likely and a slight chance of thunderstorms by mid
afternoon. waves calm to 2 feet. 
.tonight...east winds 5 to 15 knots veering southeast after
midnight, then backing northeast late. a slight chance of
thunderstorms through midnight. a chance of showers. waves calm
to 2 feet. 
.friday...north winds 5 to 15 knots backing west late. a slight
chance of showers through early afternoon. waves calm to 2 feet. 
.friday night...west winds 5 to 15 knots increasing to 10 to
20 knots after midnight. a slight chance of showers and
thunderstorms after midnight. waves calm to 2 feet. 
.saturday...northwest winds 10 to 20 knots becoming west 5 to
15 knots by mid afternoon. waves calm to 2 feet. 
.saturday night...north winds 5 to 15 knots increasing to 10 to
20 knots after midnight. waves calm to 2 feet. 
.sunday...north winds 5 to 15 knots veering south. waves calm to
2 feet. 
.monday...south winds 5 to 15 knots increasing to 10 to 20 knots.
waves calm to 2 feet. 

$$