fzus63 kmqt 182101
glfls 
expires:202512190900;;818363

open lake forecast for lake superior
national weather service marquette mi
400 pm est thu dec 18 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...

a 29.1 inch clipper lifts northeast away from the lake tonight 
before reaching northern quebec friday morning. a 29.9 inch ridge 
then returns to the lake on friday via a 30.2 inch high over the 
lower mississippi valley and a weakening 29.9 inch high over 
northern ontario. another low pressure of around 29.3 inches tracks 
north of lake superior on saturday. this is then followed by a 30.3 
inch high over the canadian prairies sliding southeast into the ohio 
river valley late this weekend, building to 30.7 inches by monday 
morning. lake superior will remain under the influence of this high 
into monday night.



lsz263-190900-
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 est thu dec 18 2025

...storm warning in effect through friday morning...
...heavy freezing spray warning in effect through friday
morning...
...gale watch in effect from saturday morning through late
saturday night...

.late this afternoon...north gales to 45 knots. freezing spray
and patchy fog. snow showers, possibly mixed with rain. waves
5 to 9 feet occasionally to 11 feet. 
.tonight...north storm force winds to 55 knots diminishing to
gales to 45 knots late. patchy dense fog in the evening. heavy
freezing spray. snow in the evening. snow likely after midnight.
waves building to 12 to 17 feet occasionally to 21 feet, then
subsiding to 11 to 15 feet occasionally to 19 feet. 
.friday...north gales to 35 knots diminishing to 15 to 25 knots
by late morning, then becoming south 5 to 15 knots by mid
afternoon. freezing spray in the morning. a chance of snow. waves
subsiding to 1 to 3 feet. 
.friday night...south winds 15 to 25 knots increasing to 20 to
30 knots by midnight, then veering southwest late. a chance of
snow in the evening, then snow likely after midnight. waves
subsiding to calm to 2 feet, then building to 4 to 7 feet
occasionally to 9 feet. 
.saturday...southwest gales to 40 knots veering west in the
afternoon. a slight chance of snow. freezing spray in the
afternoon. waves building to 12 to 17 feet occasionally to
21 feet, then subsiding to 10 to 14 feet occasionally to 18 feet.
.saturday night...northwest gales to 40 knots. heavy freezing
spray. waves subsiding to 5 to 8 feet occasionally to 10 feet. 
.sunday...northwest winds 15 to 25 knots becoming west 10 to
20 knots in the afternoon. waves subsiding to 1 to 3 feet. 
.sunday night...southwest winds 5 to 15 knots. waves 1 to 3 feet.
.monday...south winds 10 to 20 knots. waves subsiding to calm to
2 feet, then building to 2 to 4 feet. 
.tuesday...west winds 15 to 25 knots becoming north 5 to
15 knots. waves subsiding to calm to 2 feet. 

note, wave height forecasts are for ice free areas.

$$