fzus63 kmqt 180800
glfls 
expires:202604182000;;569870

open lake forecast for lake superior
national weather service marquette mi
400 am edt sat apr 18 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 low of 29.3 inches over northern ontario lifts into james bay 
later this morning. behind it, ridging builds over lake superior, 
strengthening to about 30.3 inches sunday night into monday morning. 
this ridging gives way to 29.8 inch troughing monday night into 
tuesday morning as a weakening low swings from the hudson bay 
shoreline of far northern ontario towards northern quebec. high 
pressure ridging builds back to 30.2 inches over lake superior by 
tuesday night. the high shifts east on wednesday as a 29.2 inch low 
pressure develops over the northern plains.



lsz162-182000-
lake superior west of a line from saxon harbor wi to grand
portage mn beyond 5nm-
400 am edt sat apr 18 2026 /300 am cdt sat apr 18 2026/

.early this morning...west winds 20 to 30 knots. waves 3 to
6 feet occasionally to 8 feet. 
.today...west winds to 30 knots with a few gale force gusts to
35 knots possible. a slight chance of snow showers. a slight
chance of rain showers by mid afternoon. waves building to 5 to
8 feet occasionally to 10 feet. 
.tonight...west winds 20 to 30 knots becoming northwest 15 to
25 knots after midnight. waves subsiding to 2 to 4 feet. 
.sunday...northwest winds 15 to 25 knots diminishing to 10 to
20 knots in the afternoon. waves subsiding to calm to 2 feet. 
.sunday night...northwest winds 5 to 15 knots veering north after
midnight. waves calm to 2 feet. 
.monday...south winds 10 to 20 knots increasing to 15 to 25 knots
by mid afternoon. waves building to 2 to 4 feet. 
.monday night...southwest winds 15 to 25 knots veering west after
midnight. waves subsiding to 1 to 3 feet. 
.tuesday...west winds 5 to 15 knots veering northeast. waves
subsiding to calm to 2 feet. 
.wednesday...east winds 5 to 15 knots increasing to 10 to
20 knots. a chance of rain showers. waves building to 3 to 5 feet
occasionally to 7 feet. 

$$

fzus63 kmqt 180800
glfls 
expires:202604182000;;569871

open lake forecast for lake superior
national weather service marquette mi
400 am edt sat apr 18 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 low of 29.3 inches over northern ontario lifts into james bay 
later this morning. behind it, ridging builds over lake superior, 
strengthening to about 30.3 inches sunday night into monday morning. 
this ridging gives way to 29.8 inch troughing monday night into 
tuesday morning as a weakening low swings from the hudson bay 
shoreline of far northern ontario towards northern quebec. high 
pressure ridging builds back to 30.2 inches over lake superior by 
tuesday night. the high shifts east on wednesday as a 29.2 inch low 
pressure develops over the northern plains.



lsz263-182000-
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 sat apr 18 2026

...gale warning in effect from 11 am edt this morning through
this evening...

.early this morning...west winds 15 to 25 knots. waves 4 to
7 feet occasionally to 9 feet. 
.today...west winds 20 to 30 knots increasing to gales to
35 knots in the afternoon. a slight chance of snow showers. waves
building to 8 to 12 feet occasionally to 15 feet. 
.tonight...west winds 20 to 30 knots veering northwest after
midnight, then diminishing to 15 to 25 knots late. flurries
through midnight. waves subsiding to 4 to 7 feet occasionally to
9 feet. 
.sunday...northwest winds 15 to 25 knots diminishing to 10 to
20 knots in the afternoon. waves subsiding to 1 to 3 feet. 
.sunday night...northwest winds 10 to 20 knots diminishing to
5 to 15 knots after midnight. waves subsiding to calm to 2 feet. 
.monday...southwest winds 15 to 25 knots backing south by mid
afternoon. waves building to 3 to 5 feet occasionally to 7 feet. 
.monday night...southwest winds 20 to 30 knots becoming west
15 to 25 knots after midnight. waves building to 3 to 6 feet
occasionally to 8 feet. 
.tuesday...west winds 10 to 20 knots becoming east less than
10 knots. waves subsiding to calm to 2 feet. 
.wednesday...east winds 5 to 15 knots becoming southeast 15 to
25 knots. a chance of rain showers. waves building to 3 to 5 feet
occasionally to 7 feet. 

$$