fzus63 kmqt 231401
glfls 
expires:202604232000;;855429

open lake forecast for lake superior
national weather service marquette mi
1000 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 ridging over northern ontario 
and low pressure straddling the us/canada border at north dakota, 
resulting in a rather tight pressure gradient across the lake of 
30.0 inches near whitefish bay and 29.7 inches near duluth. 
throughout today, the ontario ridge will progress slightly eastward 
while the low weakens, sending a 29.6 inch trough across of lake 
superior by friday midday. as the parent low weakens to 29.9 inches 
friday into saturday and remnant troughing moves south, 30.0 inch 
ridging will build over lake superior by late saturday. this ridge 
builds to 30.1 inches by late sunday and persists into early monday. 
meanwhile, a 29.3 inch colorado low develops, moving towards the 
upper midwest by early monday, causing pressure over lake superior 
to fall rapidly toward 29.5 inches by mid-monday. this low stalls 
out over nothern mn, causing lake superior pressures to remain low 
near 29.3 inches throughout tuesday.



lsz162-232000-
lake superior west of a line from saxon harbor wi to grand
portage mn beyond 5nm-
1000 am edt thu apr 23 2026 /900 am cdt thu apr 23 2026/

.rest of today...northeast winds 10 to 20 knots. a chance of rain
showers. a chance of thunderstorms by mid afternoon. waves 3 to
6 feet occasionally to 8 feet. 
.tonight...northeast winds 10 to 20 knots veering east after
midnight, then backing northeast late. rain showers and a chance
of thunderstorms. waves subsiding to 3 to 5 feet occasionally to
7 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 5 to 8 feet
occasionally to 10 feet, then subsiding to 3 to 6 feet
occasionally to 8 feet. 

$$

fzus63 kmqt 231401
glfls 
expires:202604232000;;855430

open lake forecast for lake superior
national weather service marquette mi
1000 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 ridging over northern ontario 
and low pressure straddling the us/canada border at north dakota, 
resulting in a rather tight pressure gradient across the lake of 
30.0 inches near whitefish bay and 29.7 inches near duluth. 
throughout today, the ontario ridge will progress slightly eastward 
while the low weakens, sending a 29.6 inch trough across of lake 
superior by friday midday. as the parent low weakens to 29.9 inches 
friday into saturday and remnant troughing moves south, 30.0 inch 
ridging will build over lake superior by late saturday. this ridge 
builds to 30.1 inches by late sunday and persists into early monday. 
meanwhile, a 29.3 inch colorado low develops, moving towards the 
upper midwest by early monday, causing pressure over lake superior 
to fall rapidly toward 29.5 inches by mid-monday. this low stalls 
out over nothern mn, causing lake superior pressures to remain low 
near 29.3 inches throughout tuesday.



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-
1000 am edt thu apr 23 2026

.rest of today...southeast winds 15 to 25 knots backing east in
the afternoon. a chance of rain showers and a slight chance of
thunderstorms by mid afternoon. waves 3 to 6 feet occasionally to
8 feet building to 4 to 7 feet occasionally to 9 feet. 
.tonight...southeast winds 20 to 30 knots. rain showers and a
chance of thunderstorms. waves building to 6 to 10 feet
occasionally to 13 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 4 to 7 feet
occasionally to 9 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 6 to 9 feet
occasionally to 11 feet. 

$$