fzus63 kmqt 232002
glfls 
expires:202604240800;;870381

open lake forecast for lake superior
national weather service marquette mi
401 pm 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...

a rather tight longitudinal pressure gradient sits across lake 
superior this afternoon, with 30.0 inches at whitefish bay and 29.7 
inches near duluth, thanks to ridging over james bay and a 29.2 inch 
low sitting just north of north dakota in canada. between now and 
friday evening, the james bay high persists while the canadian low 
swings north into manitoba, sending troughing of around 29.6 inches 
across lake superior. late friday and into saturday, the parent low 
weakens considerably as remnant troughing moves south and 30.0 inch 
ridging builds 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 29.7 inches by mid-monday. lake superior 
pressure continues to fall as this 29.3 inch low reaches mn/wi by 
late monday and lake superior by early tuesday, causing pressure 
over the lake to remain low near 29.3 throughout tuesday. this low 
lifts north into ontario wednesday morning, and lake superior 
pressures increase to 29.8 inches by wednesday midday.



lsz162-240800-
lake superior west of a line from saxon harbor wi to grand
portage mn beyond 5nm-
401 pm edt thu apr 23 2026 /301 pm cdt thu apr 23 2026/

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

$$

fzus63 kmqt 232002
glfls 
expires:202604240800;;870382

open lake forecast for lake superior
national weather service marquette mi
401 pm 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...

a rather tight longitudinal pressure gradient sits across lake 
superior this afternoon, with 30.0 inches at whitefish bay and 29.7 
inches near duluth, thanks to ridging over james bay and a 29.2 inch 
low sitting just north of north dakota in canada. between now and 
friday evening, the james bay high persists while the canadian low 
swings north into manitoba, sending troughing of around 29.6 inches 
across lake superior. late friday and into saturday, the parent low 
weakens considerably as remnant troughing moves south and 30.0 inch 
ridging builds 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 29.7 inches by mid-monday. lake superior 
pressure continues to fall as this 29.3 inch low reaches mn/wi by 
late monday and lake superior by early tuesday, causing pressure 
over the lake to remain low near 29.3 throughout tuesday. this low 
lifts north into ontario wednesday morning, and lake superior 
pressures increase to 29.8 inches by wednesday midday.



lsz263-240800-
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-
401 pm edt thu apr 23 2026

.late this afternoon...east winds 15 to 25 knots. a slight chance
of showers and thunderstorms. waves 4 to 8 feet occasionally to
10 feet. 
.tonight...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...west winds 20 to 30 knots diminishing to 10 to
20 knots. rain showers and a slight chance of thunderstorms
through early afternoon, then a chance of rain showers by mid
afternoon. waves subsiding to 3 to 6 feet occasionally to 8 feet.
.friday night...northwest winds 10 to 20 knots becoming north
5 to 15 knots after midnight, then backing northwest late. waves
subsiding to calm to 2 feet. 
.saturday...northwest winds 5 to 15 knots backing south by mid
afternoon. waves calm to 2 feet. 
.saturday night...east 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 backing northeast by mid
afternoon. waves calm to 2 feet. 
.sunday night...east winds 5 to 15 knots increasing to 10 to
20 knots after midnight. waves building to 1 to 3 feet. 
.monday...east winds 20 to 30 knots increasing to gales to
35 knots. a chance of rain showers, then rain showers likely.
waves building to 6 to 9 feet occasionally to 11 feet. 
.tuesday...west gales to 35 knots diminishing to 15 to 25 knots.
a chance of rain showers. waves subsiding to 4 to 8 feet
occasionally to 10 feet. 

$$