fzus63 kmqt 230801
glfls 
expires:202604232000;;842551

open lake forecast for lake superior
national weather service marquette mi
400 am edt thu apr 23 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...

this morning, lake superior is between 30.2 inch ridging over 
northern ontario and 29.2 inch low pressure straddling the us/canada 
border at north dakota. throughout today, the ridge will progress 
slightly to james bay while the low weakens to 29.4 inches and sends 
a 29.5 inch trough to the far western end of lake superior. as the 
parent low weakens to 29.9 inches friday into saturday and remnant 
troughing moves south of the lower great lakes at 29.7 inches, 30.0 
inch ridging will build over lake superior. by late sunday, this 
ridge builds to 30.1 inches. meanwhile, a 29.3 inch colorado low 
develops, moving towards the upper midwest by early monday, causing 
pressure over lake superior to begin to fall rapidly toward 29.5 by 
mid-monday, with the low crossing lake superior at 29.4 inches by 
tuesday afternoon.



lsz162-232000-
lake superior west of a line from saxon harbor wi to grand
portage mn beyond 5nm-
400 am edt thu apr 23 2026 /300 am cdt thu apr 23 2026/

.early this morning...east winds 10 to 20 knots. waves 2 to
4 feet. 
.today...east winds 10 to 20 knots backing northeast late. a
chance of showers and thunderstorms by mid afternoon. waves
building to 3 to 6 feet occasionally to 8 feet. 
.tonight...east winds 10 to 20 knots backing northeast late. 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. a chance of rain showers.
waves subsiding to 2 to 4 feet. 
.friday night...northwest winds 10 to 20 knots diminishing to
5 to 15 knots after midnight. a slight chance of rain showers.
waves subsiding to calm to 2 feet. 
.saturday...west winds 5 to 15 knots backing south by mid
afternoon. waves calm to 2 feet. 
.saturday night...east winds 5 to 15 knots backing northeast
after midnight. waves calm to 2 feet. 
.sunday...northeast winds 5 to 15 knots increasing to 15 to
25 knots. waves building to 3 to 5 feet occasionally to 7 feet. 
.monday...northeast winds 20 to 30 knots. a chance of rain
showers, then rain showers likely. waves building to 4 to 7 feet
occasionally to 9 feet, then subsiding to 3 to 5 feet
occasionally to 7 feet. 

$$

fzus63 kmqt 230801
glfls 
expires:202604232000;;842552

open lake forecast for lake superior
national weather service marquette mi
400 am edt thu apr 23 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...

this morning, lake superior is between 30.2 inch ridging over 
northern ontario and 29.2 inch low pressure straddling the us/canada 
border at north dakota. throughout today, the ridge will progress 
slightly to james bay while the low weakens to 29.4 inches and sends 
a 29.5 inch trough to the far western end of lake superior. as the 
parent low weakens to 29.9 inches friday into saturday and remnant 
troughing moves south of the lower great lakes at 29.7 inches, 30.0 
inch ridging will build over lake superior. by late sunday, this 
ridge builds to 30.1 inches. meanwhile, a 29.3 inch colorado low 
develops, moving towards the upper midwest by early monday, causing 
pressure over lake superior to begin to fall rapidly toward 29.5 by 
mid-monday, with the low crossing lake superior at 29.4 inches by 
tuesday afternoon.



lsz263-232000-
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 apr 23 2026

.early this morning...east winds 10 to 20 knots. a slight chance
of rain showers. waves 2 to 4 feet building to 3 to 5 feet
occasionally to 7 feet. 
.today...east winds 15 to 25 knots increasing to 20 to 30 knots
late. a slight chance of showers and thunderstorms by mid
afternoon. waves building to 6 to 9 feet occasionally to 11 feet.
.tonight...southeast winds 20 to 30 knots. rain showers and a
chance of thunderstorms. waves building to 8 to 11 feet
occasionally to 14 feet. 
.friday...west winds 20 to 30 knots diminishing to 10 to
20 knots. rain showers likely and a slight chance of
thunderstorms through early afternoon, then a chance of rain
showers by mid afternoon. waves subsiding to 5 to 8 feet
occasionally to 10 feet. 
.friday night...northwest winds 10 to 20 knots diminishing to
5 to 15 knots after midnight. a slight chance of rain showers.
waves subsiding to 1 to 3 feet. 
.saturday...west winds 5 to 15 knots backing southwest by mid
afternoon. waves subsiding to calm to 2 feet. 
.saturday night...southeast winds 5 to 15 knots diminishing to
less than 10 knots after midnight. waves calm to 2 feet. 
.sunday...east winds 5 to 15 knots increasing to 10 to 20 knots.
waves building to 1 to 3 feet. 
.monday...east winds 20 to 30 knots. a chance of rain showers,
then rain showers likely. waves building to 5 to 8 feet
occasionally to 10 feet, then subsiding to 3 to 6 feet
occasionally to 8 feet. 

$$