fzus63 kmqt 202001
glfls 
expires:202604210800;;707917

open lake forecast for lake superior
national weather service marquette mi
400 pm edt mon apr 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...

30.1 inch high pressure ridging over lake superior this afternoon 
departs to the southeast this evening. a 29.1 inch low moving from 
northern manitoba to hudson bay swings a 29.8 inch trough across 
lake superior tonight into tuesday morning. 30.0 inch high pressure 
ridging returns over the lake by tuesday afternoon as the low 
weakens over hudson bay. a 29.2 inch low then develops over the 
northern rockies on wednesday and tracks into manitoba at around 
29.5 inches on friday. this sends 29.6 inch troughing over lake 
superior thursday night into friday. 30.1 inch ridging slowly 
returns to lake superior on saturday.



lsz162-210800-
lake superior west of a line from saxon harbor wi to grand
portage mn beyond 5nm-
400 pm edt mon apr 20 2026 /300 pm cdt mon apr 20 2026/

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

$$

fzus63 kmqt 202001
glfls 
expires:202604210800;;707918

open lake forecast for lake superior
national weather service marquette mi
400 pm edt mon apr 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...

30.1 inch high pressure ridging over lake superior this afternoon 
departs to the southeast this evening. a 29.1 inch low moving from 
northern manitoba to hudson bay swings a 29.8 inch trough across 
lake superior tonight into tuesday morning. 30.0 inch high pressure 
ridging returns over the lake by tuesday afternoon as the low 
weakens over hudson bay. a 29.2 inch low then develops over the 
northern rockies on wednesday and tracks into manitoba at around 
29.5 inches on friday. this sends 29.6 inch troughing over lake 
superior thursday night into friday. 30.1 inch ridging slowly 
returns to lake superior on saturday.



lsz263-210800-
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 pm edt mon apr 20 2026

.late this afternoon...south winds 15 to 25 knots. waves 2 to
4 feet. 
.tonight...southwest winds 15 to 25 knots becoming west 10 to
20 knots late. waves building to 3 to 5 feet occasionally to
7 feet, then subsiding to 1 to 3 feet. 
.tuesday...northwest winds 5 to 15 knots diminishing to less than
10 knots in the afternoon, then becoming southwest 5 to 15 knots
late. waves subsiding to calm to 2 feet. 
.tuesday night...south winds less than 10 knots backing southeast
after midnight. waves calm to 2 feet. 
.wednesday...southeast winds less than 10 knots becoming east
5 to 15 knots by mid afternoon. waves calm to 2 feet. 
.wednesday night...east winds 5 to 15 knots becoming southeast
10 to 20 knots after midnight. waves building to 2 to 4 feet. 
.thursday...southeast winds 10 to 20 knots becoming east 15 to
25 knots by mid afternoon. waves building to 4 to 7 feet
occasionally to 9 feet. 
.thursday night...southeast winds 20 to 30 knots. rain showers
likely and a chance of thunderstorms. waves building to 7 to
10 feet occasionally to 13 feet. 
.friday...west winds 20 to 30 knots diminishing to 15 to
25 knots. a chance of rain showers. waves subsiding to 3 to
6 feet occasionally to 8 feet. 
.saturday...west winds 15 to 25 knots diminishing to 5 to
15 knots. waves subsiding to 2 to 4 feet. 

$$