fzus63 kmqt 210801
glfls 
expires:202604212000;;734384

open lake forecast for lake superior
national weather service marquette mi
400 am edt tue apr 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...

a 29.8 inch trough continues across lake superior this morning. 
behind it, 30.0 inch high pressure ridging returns over the lake by 
this evening. a 29.2 inch low then develops over the northern 
rockies on wednesday and tracks into manitoba by no later than 
thursday evening. this sends 29.6 to 29.7 inch troughing over lake 
superior thursday night into friday. 30.1 inch ridging slowly 
returns to lake superior on saturday.



lsz162-212000-
lake superior west of a line from saxon harbor wi to grand
portage mn beyond 5nm-
400 am edt tue apr 21 2026 /300 am cdt tue apr 21 2026/

.early this morning...west winds 5 to 15 knots. waves 1 to 3 feet
subsiding to calm to 2 feet. 
.today...northwest winds 5 to 15 knots backing southwest in the
afternoon, then backing south late. waves calm to 2 feet. 
.tonight...southeast winds less than 10 knots backing east after
midnight, then increasing to 5 to 15 knots late. waves calm to
2 feet. 
.wednesday...east winds 5 to 15 knots becoming northeast 10 to
20 knots late. waves calm to 2 feet. 
.wednesday night...northeast winds 10 to 20 knots veering east
after midnight. a slight chance of thunderstorms through
midnight. a slight chance of rain showers. waves building to 2 to
4 feet. 
.thursday...east winds 10 to 20 knots increasing to 15 to
25 knots by mid afternoon. a chance of rain showers by mid
afternoon. waves building to 3 to 6 feet occasionally to 8 feet. 
.thursday night...east winds 10 to 20 knots increasing to 15 to
25 knots after midnight. rain showers and a chance of
thunderstorms. waves building to 4 to 7 feet occasionally to
9 feet, then subsiding to 3 to 6 feet occasionally to 8 feet. 
.friday...north winds 15 to 25 knots becoming northwest 10 to
20 knots. a chance of rain showers. waves subsiding to 1 to
3 feet. 
.saturday...west winds 10 to 20 knots becoming north 5 to
15 knots. waves subsiding to calm to 2 feet. 

$$

fzus63 kmqt 210801
glfls 
expires:202604212000;;734385

open lake forecast for lake superior
national weather service marquette mi
400 am edt tue apr 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...

a 29.8 inch trough continues across lake superior this morning. 
behind it, 30.0 inch high pressure ridging returns over the lake by 
this evening. a 29.2 inch low then develops over the northern 
rockies on wednesday and tracks into manitoba by no later than 
thursday evening. this sends 29.6 to 29.7 inch troughing over lake 
superior thursday night into friday. 30.1 inch ridging slowly 
returns to lake superior on saturday.



lsz263-212000-
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 tue apr 21 2026

.early this morning...west winds 10 to 20 knots. waves 2 to
4 feet subsiding to 1 to 3 feet. 
.today...northwest winds 5 to 15 knots becoming west less than
10 knots in the afternoon, then backing southwest late. waves
subsiding to calm to 2 feet. 
.tonight...southeast winds 5 to 15 knots diminishing to less than
10 knots after midnight. waves calm to 2 feet. 
.wednesday...southeast winds less than 10 knots becoming east
5 to 15 knots in the afternoon. waves calm to 2 feet. 
.wednesday night...east winds 10 to 20 knots. a slight chance of
rain showers. waves building to 3 to 5 feet occasionally to
7 feet. 
.thursday...east winds 15 to 25 knots increasing to 20 to
30 knots by mid afternoon. waves building to 5 to 8 feet
occasionally to 10 feet. 
.thursday night...southeast winds 20 to 30 knots. rain showers
and a chance of thunderstorms. waves building to 7 to 10 feet
occasionally to 13 feet. 
.friday...southeast winds 20 to 30 knots becoming west 10 to
20 knots. rain showers likely. waves subsiding to 2 to 4 feet. 
.saturday...west winds 10 to 20 knots becoming north 5 to
15 knots. waves subsiding to calm to 2 feet. 

$$