fzus63 kmqt 202001
glfls 
expires:202608210800;;067310

open lake forecast for lake superior
national weather service marquette mi
401 pm edt thu aug 20 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 afternoon, lake superior remains in between 30.0 inch high 
pressure over southern ontario and a 29.8 inch low pressure 
currently moving into minnesota. the aforementioned low weakens 
while moving eastward, and brings 29.9 inch troughing over the 
western half of the lake late tonight. friday into this weekend, a 
low pressure of around 29.8 inches transits across northern ontario, 
reinforcing 29.9 inch troughing over lake superior friday into 
saturday morning. this is quickly followed by 30.1 inch ridging for 
the latter part of the weekend into early next week via a 30.2 inch 
parent high from canada that drops down into the ohio river valley 
by late monday.




lsz162-210800-
lake superior west of a line from saxon harbor wi to grand
portage mn beyond 5nm-
401 pm edt thu aug 20 2026 /301 pm cdt thu aug 20 2026/

.late this afternoon...east winds 10 to 20 knots. a chance of
showers and thunderstorms. waves calm to 2 feet. 
.tonight...east winds 5 to 15 knots backing northeast after
midnight. a chance of showers and thunderstorms through midnight.
waves calm to 2 feet. 
.friday...north winds 5 to 15 knots backing southwest in the
afternoon. waves calm to 2 feet. 
.friday night...southwest winds 5 to 15 knots veering west after
midnight, then becoming northwest 10 to 20 knots late. waves calm
to 2 feet. 
.saturday...northwest winds 10 to 20 knots becoming west 5 to
15 knots by mid afternoon. waves calm to 2 feet. 
.saturday night...north winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. waves calm to 2 feet. 
.sunday...north winds 5 to 15 knots veering south by mid
afternoon. waves calm to 2 feet. 
.sunday night...south winds 5 to 15 knots becoming north less
than 10 knots after midnight. waves calm to 2 feet. 
.monday...east winds 5 to 15 knots veering south. waves calm to
2 feet. 
.tuesday...southwest winds 5 to 15 knots becoming northwest 10 to
20 knots. a chance of showers and thunderstorms. waves calm to
2 feet. 

$$

fzus63 kmqt 202001
glfls 
expires:202608210800;;067311

open lake forecast for lake superior
national weather service marquette mi
401 pm edt thu aug 20 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 afternoon, lake superior remains in between 30.0 inch high 
pressure over southern ontario and a 29.8 inch low pressure 
currently moving into minnesota. the aforementioned low weakens 
while moving eastward, and brings 29.9 inch troughing over the 
western half of the lake late tonight. friday into this weekend, a 
low pressure of around 29.8 inches transits across northern ontario, 
reinforcing 29.9 inch troughing over lake superior friday into 
saturday morning. this is quickly followed by 30.1 inch ridging for 
the latter part of the weekend into early next week via a 30.2 inch 
parent high from canada that drops down into the ohio river valley 
by late monday.




lsz263-210800-
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 aug 20 2026

.late this afternoon...east winds 5 to 15 knots. showers likely
and a slight chance of thunderstorms. waves calm to 2 feet. 
.tonight...east winds 5 to 15 knots veering southeast after
midnight, then backing northeast late. a slight chance of
thunderstorms through midnight. a chance of showers. waves calm
to 2 feet. 
.friday...northeast winds 5 to 15 knots backing north in the
afternoon, then backing west late. a slight chance of showers
through early afternoon. waves calm to 2 feet. 
.friday night...southwest winds 5 to 15 knots veering west after
midnight, then becoming northwest 10 to 20 knots late. a slight
chance of showers after midnight. waves calm to 2 feet. 
.saturday...northwest winds 10 to 20 knots becoming west 5 to
15 knots by mid afternoon. a slight chance of showers. waves calm
to 2 feet. 
.saturday night...north winds 10 to 20 knots. waves calm to
2 feet. 
.sunday...north winds 10 to 20 knots becoming southwest 5 to
15 knots by mid afternoon. waves calm to 2 feet. 
.sunday night...southwest winds 5 to 15 knots becoming south less
than 10 knots after midnight. waves calm to 2 feet. 
.monday...south winds 5 to 15 knots. waves calm to 2 feet. 
.tuesday...southwest winds 10 to 20 knots becoming west 15 to
25 knots. a chance of showers. waves building to 1 to 3 feet. 

$$