Great Lakes Forecast
Issued by NWS

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539
FZUS63 KMQT 052001
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
401 PM EDT Sun Oct 5 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 29.4 inch low over far northern Minnesota and southern Ontario
will move to James Bay by late tonight, reaching far northern Quebec
as it deepens to 29.2 inches by Monday morning. This results in 29.7
inch troughing over Lake Superior through tonight. In its wake, a
30.3 inch high pressure moving across the Northern Plains builds
30.1 inch ridging back over Lake Superior Monday through Tuesday.
The ridge strengthens to 30.4 inches over the lake on Wednesday as
reinforcing high pressure moves overhead from the Canadian Prairies.
The high shifts east to New England by Thursday night, allowing 29.8
inch troughing to return to the lake as a 29.2 inch low moves over
Hudson Bay Friday morning.


LSZ162-060800-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
401 PM EDT Sun Oct 5 2025 /301 PM CDT Sun Oct 5 2025/

...GALE WARNING IN EFFECT THROUGH LATE TONIGHT...

.LATE THIS AFTERNOON...South gales to 40 knots. A chance of
showers. Waves 5 to 9 feet occasionally to 11 feet.
.TONIGHT...South gales to 40 knots becoming northwest gales to
45 knots after midnight, then diminishing to 20 to 30 knots late.
Waves building to 7 to 10 feet occasionally to 13 feet, then
subsiding to 1 to 3 feet.
.MONDAY...Northwest winds 10 to 20 knots backing southwest late.
Waves subsiding to calm to 2 feet.
.MONDAY NIGHT...West winds 10 to 20 knots increasing to 15 to
25 knots late. Waves building to 1 to 3 feet.
.TUESDAY...West winds 15 to 25 knots becoming northwest 10 to
20 knots by mid afternoon. Waves building to 2 to 4 feet, then
subsiding to calm to 2 feet.
.TUESDAY NIGHT...North winds 5 to 15 knots. Waves calm to 2 feet.
.WEDNESDAY...Southeast winds 5 to 15 knots. Waves calm to 2 feet.
.WEDNESDAY NIGHT...Southeast winds 10 to 20 knots veering south
after midnight. Waves building to 1 to 3 feet.
.THURSDAY...Southwest winds 15 to 25 knots diminishing to 10 to
20 knots. Waves building to 2 to 4 feet, then subsiding to calm
to 2 feet.
.FRIDAY...West winds 10 to 20 knots becoming southwest 5 to
15 knots. Waves calm to 2 feet.

$$

LSZ263-060800-
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 Sun Oct 5 2025

...GALE WARNING IN EFFECT THROUGH LATE TONIGHT...

.LATE THIS AFTERNOON...South gales to 40 knots. A slight chance
of showers. Waves 5 to 9 feet occasionally to 11 feet.
.TONIGHT...South gales to 40 knots becoming northwest gales to
35 knots after midnight, then diminishing to 20 to 30 knots late.
A slight chance of showers through midnight. Waves building to
7 to 10 feet occasionally to 13 feet, then subsiding to 3 to
6 feet occasionally to 8 feet.
.MONDAY...Northwest winds 10 to 20 knots backing southwest late.
Waves subsiding to calm to 2 feet, then building to 1 to 3 feet.
.MONDAY NIGHT...West winds 10 to 20 knots increasing to 15 to
25 knots after midnight. Waves building to 3 to 5 feet
occasionally to 7 feet.
.TUESDAY...West winds 15 to 25 knots veering northwest by mid
afternoon. Waves building to 3 to 6 feet occasionally to 8 feet,
then subsiding to 1 to 3 feet.
.TUESDAY NIGHT...North winds 5 to 15 knots. Waves subsiding to
calm to 2 feet.
.WEDNESDAY...South winds 5 to 15 knots. Waves calm to 2 feet.
.WEDNESDAY NIGHT...South winds 5 to 15 knots increasing to 15 to
25 knots after midnight. Waves building to 2 to 4 feet.
.THURSDAY...Southwest winds 20 to 30 knots diminishing to 15 to
25 knots. Waves building to 3 to 5 feet occasionally to 7 feet,
then subsiding to 2 to 4 feet.
.FRIDAY...West winds 10 to 20 knots becoming southwest 5 to
15 knots. Waves subsiding to calm to 2 feet.

$$

LSZ264-060800-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
401 PM EDT Sun Oct 5 2025

...GALE WARNING IN EFFECT UNTIL 2 AM EDT MONDAY...

.LATE THIS AFTERNOON...South gales to 35 knots. A slight chance
of showers. Waves 5 to 8 feet occasionally to 10 feet.
.TONIGHT...South gales to 35 knots veering west after midnight,
then becoming northwest 20 to 30 knots late. A slight chance of
showers through midnight. Waves building to 6 to 9 feet
occasionally to 11 feet, then subsiding to 4 to 7 feet
occasionally to 9 feet.
.MONDAY...Northwest winds 15 to 25 knots becoming west 10 to
20 knots in the afternoon, then backing southwest late. Waves
subsiding to calm to 2 feet.
.MONDAY NIGHT...West winds 10 to 20 knots increasing to 15 to
25 knots after midnight. Waves building to 3 to 5 feet
occasionally to 7 feet.
.TUESDAY...West winds 15 to 25 knots veering northwest by mid
afternoon. Waves building to 3 to 6 feet occasionally to 8 feet,
then subsiding to 2 to 4 feet.
.TUESDAY NIGHT...North winds 5 to 15 knots. Waves subsiding to
calm to 2 feet.
.WEDNESDAY...Southwest winds 5 to 15 knots backing south by mid
afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...South winds 5 to 15 knots increasing to 10 to
20 knots after midnight. Waves building to 1 to 3 feet.
.THURSDAY...Southwest winds 15 to 25 knots. Waves building to
2 to 4 feet.
.FRIDAY...West winds 10 to 20 knots diminishing to 5 to 15 knots.
Waves subsiding to calm to 2 feet.

$$

LSZ265-060800-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
401 PM EDT Sun Oct 5 2025

...GALE WARNING IN EFFECT UNTIL 2 AM EDT MONDAY...

.LATE THIS AFTERNOON...Southeast gales to 35 knots. Waves 3 to
6 feet occasionally to 8 feet.
.TONIGHT...South gales to 40 knots becoming west gales to
35 knots after midnight, then veering northwest late. A slight
chance of thunderstorms through midnight. A chance of showers.
Waves building to 4 to 7 feet occasionally to 9 feet, then
subsiding to 3 to 5 feet occasionally to 7 feet.
.MONDAY...Northwest winds 20 to 30 knots diminishing to 10 to
20 knots in the afternoon, then backing west late. Waves
subsiding to calm to 2 feet.
.MONDAY NIGHT...West winds 5 to 15 knots increasing to 15 to
25 knots. Waves calm to 2 feet.
.TUESDAY...West winds 15 to 25 knots becoming northwest 20 to
30 knots by mid afternoon. Waves building to 1 to 3 feet.
.TUESDAY NIGHT...North winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. Waves subsiding to calm to 2 feet.
.WEDNESDAY...North winds 5 to 15 knots becoming southeast 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...Southeast winds 10 to 20 knots becoming south
15 to 25 knots after midnight. Waves calm to 2 feet.
.THURSDAY...South winds 15 to 25 knots veering southwest. A
chance of showers. Waves calm to 2 feet.
.FRIDAY...West winds 10 to 20 knots. Waves calm to 2 feet.

$$

LSZ266-060800-
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 PM EDT Sun Oct 5 2025

...GALE WARNING IN EFFECT UNTIL 2 AM EDT MONDAY...

.LATE THIS AFTERNOON...South gales to 40 knots. Waves 5 to 9 feet
occasionally to 11 feet.
.TONIGHT...South gales to 40 knots becoming west gales to
35 knots after midnight, then becoming northwest 20 to 30 knots
late. A chance of showers and a slight chance of thunderstorms.
Waves building to 7 to 10 feet occasionally to 13 feet, then
subsiding to 5 to 8 feet occasionally to 10 feet.
.MONDAY...Northwest winds 20 to 30 knots diminishing to 5 to
15 knots. A slight chance of showers through early afternoon.
Waves subsiding to 1 to 3 feet.
.MONDAY NIGHT...West winds 5 to 15 knots increasing to 10 to
20 knots after midnight. A slight chance of showers through
midnight. Waves building to 3 to 5 feet occasionally to 7 feet.
.TUESDAY...West winds 15 to 25 knots veering northwest by mid
afternoon. Waves building to 4 to 7 feet occasionally to 9 feet,
then subsiding to 3 to 6 feet occasionally to 8 feet.
.TUESDAY NIGHT...North winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. Waves subsiding to 1 to 3 feet.
.WEDNESDAY...North winds 5 to 15 knots veering south by mid
afternoon. Waves subsiding to calm to 2 feet.
.WEDNESDAY NIGHT...South winds 10 to 20 knots. Waves building to
1 to 3 feet.
.THURSDAY...South winds 15 to 25 knots veering southwest. A
chance of showers. Waves building to 3 to 5 feet occasionally to
7 feet, then subsiding to 2 to 4 feet.
.FRIDAY...West winds 10 to 20 knots. Waves subsiding to calm to
2 feet.

$$

LSZ267-060800-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
401 PM EDT Sun Oct 5 2025

.LATE THIS AFTERNOON...Southeast winds to 30 knots with a few
gale force gusts to 35 knots possible. Waves 4 to 8 feet
occasionally to 10 feet.
.TONIGHT...South winds to 30 knots with a few gale force gusts to
35 knots possible veering southwest after midnight, then becoming
west 20 to 30 knots late. A chance of showers through midnight. A
slight chance of thunderstorms. Showers after midnight. Waves
subsiding to 4 to 7 feet occasionally to 9 feet.
.MONDAY...Northwest winds 20 to 30 knots diminishing to 10 to
20 knots. A chance of showers through early afternoon. Waves
subsiding to 2 to 4 feet.
.MONDAY NIGHT...West winds 10 to 20 knots. A chance of showers
through midnight. Waves subsiding to calm to 2 feet, then
building to 2 to 4 feet.
.TUESDAY...West winds 15 to 25 knots becoming northwest 20 to
30 knots by mid afternoon. Waves building to 4 to 7 feet
occasionally to 9 feet.
.TUESDAY NIGHT...North winds 15 to 25 knots diminishing to 10 to
20 knots after midnight. Waves subsiding to 1 to 3 feet.
.WEDNESDAY...North winds 10 to 20 knots diminishing to 5 to
15 knots by mid afternoon. Waves subsiding to calm to 2 feet.
.WEDNESDAY NIGHT...South winds 5 to 15 knots increasing to 10 to
20 knots after midnight. Waves building to 1 to 3 feet.
.THURSDAY...South winds 15 to 25 knots veering southwest. A
chance of showers. Waves building to 3 to 5 feet occasionally to
7 feet, then subsiding to 2 to 4 feet.
.FRIDAY...West winds 15 to 25 knots diminishing to 10 to
20 knots. A chance of showers. Waves subsiding to calm to 2 feet.

$$

LSZ261-060200-
MAFOR 0521/
Superior West...GALE WARNING IN EFFECT...11450 11550 11650 11740
11730 11720 12610. A chance of showers early this evening. Waves
5 to 8 feet subsiding to 3 to 6 feet tonight. Waves 3 to 5 feet
subsiding to 1 to 3 feet Monday.

Superior North Central...GALE WARNING IN EFFECT...12450 11550
11750 11740 11730 11720 11620. Waves 5 to 9 feet tonight. Waves 5
to 8 feet subsiding to 1 to 3 feet Monday.

Superior South Central...GALE WARNING IN EFFECT...11350 11450
11550 11640 11740 11730 12720. A chance of showers tonight. Waves
3 to 6 feet building to 4 to 7 feet tonight. Waves 3 to 6 feet
subsiding to 2 to 4 feet Monday.

Superior East...GALE WARNING IN EFFECT...13450 11546 11740 12730
11720. Waves 5 to 9 feet building to 6 to 10 feet, then subsiding
to 4 to 7 feet tonight. Waves 5 to 7 feet subsiding to 3 to 5
feet Monday.

$$

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