fzus63 kmqt 092008 cca
glfls 
expires:202510100800;;394766

open lake forecast for lake superior...corrected
national weather service marquette mi
408 pm edt thu oct 9 2025

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...

30.5 inch high pressure continues to slide eastward this evening, 
becoming centered over new england later tonight. this allows a 30.0 
inch trough to move into the upper great lakes as a 29.4 inch low 
moves over hudson bay. along this trough, a 29.9 inch low will 
develop near thunder bay, then move over lake superior friday 
afternoon and evening. the low drops into lower michigan friday 
night and saturday while 30.1 inch ridging builds over the lake. 
this ridge gradually weakens through the weekend as the next system 
organizes upstream in the northern plains. by early monday, deep 
29.4 inch low pressure will be moving into manitoba and ontario, 
with a 29.8 to 29.9 inch trough moving over the lake before ridging 
recovers late monday into tuesday.



lsz162-100800-
lake superior west of a line from saxon harbor wi to grand
portage mn beyond 5nm-
408 pm edt thu oct 9 2025 /308 pm cdt thu oct 9 2025/

.late this afternoon...south winds 10 to 20 knots. waves 1 to
3 feet subsiding to calm to 2 feet. 
.tonight...south winds 15 to 25 knots becoming southwest 20 to
30 knots after midnight, then diminishing to 15 to 25 knots late.
a chance of showers. waves building to 3 to 6 feet occasionally
to 8 feet. 
.friday...northwest winds 20 to 30 knots. a slight chance of
showers. waves subsiding to 2 to 4 feet. 
.friday night...north winds 15 to 25 knots diminishing to 10 to
20 knots after midnight, then veering northeast late. waves
subsiding to calm to 2 feet. 
.saturday...east winds 5 to 15 knots. waves calm to 2 feet. 
.saturday night...east winds 10 to 20 knots veering south after
midnight. waves building to 2 to 4 feet. 
.sunday...southeast winds 10 to 20 knots increasing to 15 to
25 knots by mid afternoon. a chance of showers. waves building to
3 to 5 feet occasionally to 7 feet. 
.sunday night...southeast winds 20 to 30 knots veering south
after midnight. showers. waves building to 4 to 7 feet
occasionally to 9 feet. 
.monday...southwest winds 20 to 30 knots becoming west 15 to
25 knots. a chance of showers. waves subsiding to 1 to 3 feet. 
.tuesday...northwest winds 10 to 20 knots veering north. waves
subsiding to calm to 2 feet. 

$$

fzus63 kmqt 092008 cca
glfls 
expires:202510100800;;394767

open lake forecast for lake superior...corrected
national weather service marquette mi
408 pm edt thu oct 9 2025

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...

30.5 inch high pressure continues to slide eastward this evening, 
becoming centered over new england later tonight. this allows a 30.0 
inch trough to move into the upper great lakes as a 29.4 inch low 
moves over hudson bay. along this trough, a 29.9 inch low will 
develop near thunder bay, then move over lake superior friday 
afternoon and evening. the low drops into lower michigan friday 
night and saturday while 30.1 inch ridging builds over the lake. 
this ridge gradually weakens through the weekend as the next system 
organizes upstream in the northern plains. by early monday, deep 
29.4 inch low pressure will be moving into manitoba and ontario, 
with a 29.8 to 29.9 inch trough moving over the lake before ridging 
recovers late monday into tuesday.



lsz263-100800-
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-
408 pm edt thu oct 9 2025

...gale warning in effect from friday morning through friday
evening...

.late this afternoon...south winds 10 to 20 knots. waves 1 to
3 feet. 
.tonight...south winds 20 to 30 knots veering southwest after
midnight. a chance of showers through midnight, then showers
likely after midnight. waves building to 3 to 6 feet occasionally
to 8 feet. 
.friday...west gales to 35 knots becoming northwest gales to
40 knots in the afternoon. a chance of showers. waves building to
4 to 7 feet occasionally to 9 feet, then subsiding to 3 to 6 feet
occasionally to 8 feet. 
.friday night...north winds 20 to 30 knots diminishing to 15 to
25 knots after midnight, then becoming northeast 10 to 20 knots
late. waves subsiding to 2 to 4 feet. 
.saturday...east winds 5 to 15 knots. waves subsiding to calm to
2 feet. 
.saturday night...southeast winds 10 to 20 knots becoming south
15 to 25 knots after midnight. waves building to 2 to 4 feet. 
.sunday...southeast winds 15 to 25 knots increasing to 20 to
30 knots by mid afternoon. waves building to 3 to 6 feet
occasionally to 8 feet. 
.sunday night...southeast gales to 35 knots veering south after
midnight. a chance of showers through midnight, then showers
likely after midnight. waves building to 4 to 7 feet occasionally
to 9 feet. 
.monday...southwest gales to 35 knots becoming west 20 to
30 knots. waves building to 5 to 8 feet occasionally to 10 feet,
then subsiding to 3 to 6 feet occasionally to 8 feet. 
.tuesday...northwest winds 15 to 25 knots becoming north 10 to
20 knots. waves subsiding to calm to 2 feet. 

$$