587
FZUS63 KMQT 080801
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
401 AM EDT Wed Oct 8 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...

Ridging will build over the lake tonight and strengthen to 30.4
inches by this afternoon, with the high transiting the Upper Great
Lakes. The high shifts east to New England by Thursday night at 30.5
inches, allowing 30.0 inch troughing 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, then move over Lake Superior Friday
afternoon and evening. The low continues into Lake 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.


LSZ162-082000-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
401 AM EDT Wed Oct 8 2025 /301 AM CDT Wed Oct 8 2025/

.EARLY THIS MORNING...North winds 5 to 15 knots. Waves calm to
2 feet.
.TODAY...Northwest winds 5 to 15 knots backing southwest in the
afternoon. Waves calm to 2 feet.
.TONIGHT...Southeast winds 5 to 15 knots becoming south 10 to
20 knots after midnight. Waves calm to 2 feet.
.THURSDAY...Southwest winds 10 to 20 knots becoming south 15 to
25 knots in the afternoon, then diminishing to 10 to 20 knots
late. Waves building to 2 to 4 feet, then subsiding to 1 to
3 feet.
.THURSDAY NIGHT...Southwest winds 15 to 25 knots diminishing to
10 to 20 knots after midnight. A chance of showers. Waves
building to 2 to 4 feet, then subsiding to 1 to 3 feet.
.FRIDAY...Northwest winds 10 to 20 knots. Waves subsiding to calm
to 2 feet.
.FRIDAY NIGHT...North winds 10 to 20 knots veering northeast
after midnight. Waves calm to 2 feet.
.SATURDAY...East winds 10 to 20 knots veering southeast. Waves
building to 2 to 4 feet.
.SUNDAY...Southeast winds 15 to 25 knots veering south. A chance
of showers, then showers likely. Waves 2 to 4 feet.

$$

LSZ263-082000-
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 AM EDT Wed Oct 8 2025

.EARLY THIS MORNING...North winds 5 to 15 knots. Waves calm to
2 feet.
.TODAY...Northwest winds 5 to 15 knots backing southwest in the
afternoon. Waves calm to 2 feet.
.TONIGHT...South winds 5 to 15 knots increasing to 10 to 20 knots
late. Waves building to 1 to 3 feet.
.THURSDAY...Southwest winds 15 to 25 knots backing south late.
Waves building to 3 to 5 feet occasionally to 7 feet, then
subsiding to 2 to 4 feet.
.THURSDAY NIGHT...Southwest winds 20 to 30 knots diminishing to
15 to 25 knots after midnight. A chance of showers. Waves
subsiding to 1 to 3 feet, then building to 3 to 5 feet
occasionally to 7 feet.
.FRIDAY...Northwest winds 10 to 20 knots. A chance of showers.
Waves subsiding to calm to 2 feet.
.FRIDAY NIGHT...North winds 5 to 15 knots veering northeast after
midnight. Waves calm to 2 feet.
.SATURDAY...East winds 5 to 15 knots becoming southeast 10 to
20 knots. Waves building to 2 to 4 feet.
.SUNDAY...Southeast winds 15 to 25 knots veering south. A chance
of showers. Waves building to 3 to 5 feet occasionally to 7 feet,
then subsiding to 2 to 4 feet.

$$

LSZ264-082000-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
401 AM EDT Wed Oct 8 2025

.EARLY THIS MORNING...North winds 5 to 15 knots. Waves 1 to
3 feet.
.TODAY...North winds 5 to 15 knots backing west in the afternoon,
then backing southwest late. Waves subsiding to calm to 2 feet.
.TONIGHT...Southwest winds 5 to 15 knots backing south after
midnight, then increasing to 10 to 20 knots late. Waves building
to 1 to 3 feet.
.THURSDAY...Southwest winds 10 to 20 knots backing south late.
Waves building to 2 to 4 feet.
.THURSDAY NIGHT...South winds 15 to 25 knots veering southwest
after midnight. A chance of showers. Waves subsiding to 1 to
3 feet, then building to 3 to 5 feet occasionally to 7 feet.
.FRIDAY...Northwest winds 10 to 20 knots veering north by mid
afternoon. A chance of showers. Waves subsiding to 1 to 3 feet.
.FRIDAY NIGHT...North winds 5 to 15 knots veering northeast after
midnight. Waves subsiding to calm to 2 feet.
.SATURDAY...East winds 5 to 15 knots becoming southeast 10 to
20 knots. Waves building to 2 to 4 feet.
.SUNDAY...Southeast winds 20 to 30 knots becoming south 15 to
25 knots. A chance of showers. Waves building to 3 to 6 feet
occasionally to 8 feet.

$$

LSZ265-082000-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
401 AM EDT Wed Oct 8 2025

.EARLY THIS MORNING...North winds 10 to 20 knots. Isolated
showers. Waves 2 to 4 feet.
.TODAY...North winds 10 to 20 knots backing northwest in the
afternoon, then diminishing to 5 to 15 knots late. Waves
subsiding to calm to 2 feet.
.TONIGHT...Southeast winds 5 to 15 knots becoming south 10 to
20 knots after midnight. Waves calm to 2 feet.
.THURSDAY...Southwest winds 10 to 20 knots becoming south 15 to
25 knots in the afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...South winds 15 to 25 knots veering southwest
after midnight. A chance of showers. Waves calm to 2 feet.
.FRIDAY...West winds 15 to 25 knots veering northwest by mid
afternoon. A chance of showers. Waves calm to 2 feet.
.FRIDAY NIGHT...North winds 10 to 20 knots. A chance of showers.
Waves calm to 2 feet.
.SATURDAY...East winds 10 to 20 knots veering southeast. Waves
calm to 2 feet.
.SUNDAY...Southeast winds 15 to 25 knots becoming south 20 to
30 knots. A chance of showers. Waves building to 2 to 4 feet,
then subsiding to 1 to 3 feet.

$$

LSZ266-082000-
Lake Superior East of a line from Manitou Island to Marquette MI
and West of a line from Grand Marais MI to the US/Canadian Border
Beyond 5NM from shore-
401 AM EDT Wed Oct 8 2025

.EARLY THIS MORNING...North winds 10 to 20 knots. Isolated
showers. Waves 3 to 6 feet occasionally to 8 feet.
.TODAY...North winds 10 to 20 knots backing northwest in the
afternoon, then diminishing to 5 to 15 knots late. Isolated
showers through early afternoon. Waves subsiding to calm to
2 feet.
.TONIGHT...Northwest winds 5 to 15 knots backing south after
midnight, then increasing to 10 to 20 knots late. Waves building
to 1 to 3 feet.
.THURSDAY...South winds 10 to 20 knots increasing to 15 to
25 knots in the afternoon. Waves building to 2 to 4 feet.
.THURSDAY NIGHT...South winds 15 to 25 knots becoming southwest
20 to 30 knots after midnight. A chance of showers after
midnight. Waves building to 3 to 6 feet occasionally to 8 feet.
.FRIDAY...Southwest winds 15 to 25 knots veering northwest by mid
afternoon. Showers likely through early afternoon, then a chance
of showers by mid afternoon. Waves subsiding to 1 to 3 feet.
.FRIDAY NIGHT...North winds 10 to 20 knots veering northeast
after midnight. A chance of showers. Waves subsiding to calm to
2 feet.
.SATURDAY...East winds 10 to 20 knots veering southeast. Waves
building to 2 to 4 feet.
.SUNDAY...Southeast winds 15 to 25 knots becoming south 20 to
30 knots. A chance of showers. Waves building to 3 to 6 feet
occasionally to 8 feet.

$$

LSZ267-082000-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
401 AM EDT Wed Oct 8 2025

.EARLY THIS MORNING...North winds 10 to 20 knots. Isolated
showers. Waves 3 to 5 feet occasionally to 7 feet subsiding to
2 to 4 feet.
.TODAY...North winds 10 to 20 knots becoming northwest 5 to
15 knots late. Isolated showers through early afternoon. Waves
subsiding to calm to 2 feet.
.TONIGHT...Northwest winds 5 to 15 knots backing south after
midnight. Waves calm to 2 feet.
.THURSDAY...South winds 10 to 20 knots increasing to 15 to
25 knots late. Waves building to 2 to 4 feet.
.THURSDAY NIGHT...South winds 15 to 25 knots veering southwest
after midnight. A chance of showers after midnight. Waves
building to 3 to 5 feet occasionally to 7 feet.
.FRIDAY...Southwest winds 20 to 30 knots becoming northwest 15 to
25 knots by mid afternoon. Showers likely. Waves subsiding to
2 to 4 feet.
.FRIDAY NIGHT...North winds 10 to 20 knots veering northeast
after midnight. A chance of showers. Waves subsiding to calm to
2 feet.
.SATURDAY...East winds 10 to 20 knots veering southeast. Waves
building to 1 to 3 feet.
.SUNDAY...Southeast winds 15 to 25 knots. A chance of showers.
Waves building to 2 to 4 feet.

$$

LSZ261-081400-
MAFOR 0809/
Superior West 11800 11700 12500 11400 11300 11310 11410. Waves 2
feet or less.

Superior North Central 12810 11700 12600 11500 12410. Waves 1 to
3 feet subsiding to 1 foot or less today. Waves 2 feet or less
tonight.

Superior South Central 12810 12700 11800 11300 11400 11410. Waves
3 to 5 feet subsiding to 1 to 3 feet today. Waves 2 feet or less
tonight.

Superior East 12810 11800 13700 11500 11400. Waves 3 to 5 feet
subsiding to 1 to 2 feet today. Waves 1 foot or less tonight.

$$

WFO MQT

Experimental modernized open lake forecast is available online at
weather.gov/mqt/glftable

Graphical marine forecasts are available online at:
weather.gov/greatlakes