fzus63 kmqt 182001
glfls 
expires:202604190800;;597861

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

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 30.0 
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. the low deepens to 29.1 inches on thursday over north 
dakota, then likely moves northeast to northern ontario through 
friday. this sends a 29.5 inch trough across the lake.



lsz162-190800-
lake superior west of a line from saxon harbor wi to grand
portage mn beyond 5nm-
400 pm edt sat apr 18 2026 /300 pm cdt sat apr 18 2026/

.late this afternoon...west winds to 30 knots with a few gale
force gusts to 35 knots possible. waves 4 to 7 feet occasionally
to 9 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 10 to 20 knots becoming north
5 to 15 knots after midnight. waves calm to 2 feet. 
.monday...south winds 10 to 20 knots. waves building to 2 to
4 feet. 
.monday night...southwest winds 15 to 25 knots becoming west
10 to 20 knots after midnight. waves subsiding to calm to 2 feet.
.tuesday...west winds 5 to 15 knots backing southwest by mid
afternoon. waves calm to 2 feet. 
.tuesday night...northeast winds 5 to 15 knots. waves 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 6 feet
occasionally to 8 feet. 
.thursday...east winds 15 to 25 knots. a chance of rain showers,
then rain showers likely. waves subsiding to 3 to 5 feet
occasionally to 7 feet, then building to 6 to 9 feet occasionally
to 11 feet. 

$$

fzus63 kmqt 182001
glfls 
expires:202604190800;;597862

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

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 30.0 
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. the low deepens to 29.1 inches on thursday over north 
dakota, then likely moves northeast to northern ontario through 
friday. this sends a 29.5 inch trough across the lake.



lsz263-190800-
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 sat apr 18 2026

...gale warning in effect until 8 pm edt this evening...

.late this afternoon...west gales to 35 knots. flurries. waves
8 to 11 feet occasionally to 14 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 3 to 6 feet occasionally to
8 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 5 to 15 knots veering north after
midnight, then backing northwest late. waves subsiding to calm to
2 feet. 
.monday...southwest winds 10 to 20 knots becoming south 15 to
25 knots by mid afternoon. waves building to 3 to 5 feet
occasionally to 7 feet. 
.monday night...south winds 15 to 25 knots veering west after
midnight. waves building to 3 to 6 feet occasionally to 8 feet,
then subsiding to 2 to 4 feet. 
.tuesday...west winds 5 to 15 knots. waves subsiding to calm to
2 feet. 
.tuesday night...east winds less than 10 knots. waves calm to
2 feet. 
.wednesday...east winds 5 to 15 knots becoming southeast 15 to
25 knots. waves building to 3 to 6 feet occasionally to 8 feet. 
.thursday...east winds 15 to 25 knots becoming southeast 20 to
30 knots. a chance of rain showers, then rain showers likely.
waves building to 7 to 10 feet occasionally to 13 feet. 

$$