960
FZUS63 KMQT 011401
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1001 AM EDT Mon Sep 1 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 30.3 inch high currently over the St Lawrence Seaway will weaken
to 30.2 inches through the evening and shift east. Tuesday, a 30.0
inch trough over northern Ontario in the early morning hours will
deepen to 29.8 inches as it moves over the lake in the evening
hours. The trough deepens to 29.6 inches by Wednesday afternoon over
the eastern half of the lake. By Thursday morning, the trough will
consolidate into a surface low of 29.4 inches over northeast
Ontario. Thursday evening, the low will pivot to far northeastern
Ontario while a low of 29.5 inches moves into Minnesota. The second
low will pass near Lake Superior Friday at around 29.5 inches before
consolidating with the northern Ontario low. The low will shift
northeast as 30.1 inch high pressure moves into the Midwest for the
weekend.


LSZ162-012000-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1001 AM EDT Mon Sep 1 2025 /901 AM CDT Mon Sep 1 2025/

.REST OF TODAY...Southwest winds 10 to 20 knots diminishing to
5 to 15 knots in the afternoon. Isolated showers and
thunderstorms by late morning. Waves calm to 2 feet.
.TONIGHT...South winds 5 to 15 knots veering southwest after
midnight. Waves calm to 2 feet.
.TUESDAY...Southwest winds 5 to 15 knots increasing to 10 to
20 knots in the afternoon. A chance of showers and thunderstorms
by mid afternoon. Waves calm to 2 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots becoming northwest
15 to 25 knots after midnight. Showers likely through midnight. A
chance of thunderstorms. A chance of showers after midnight.
Waves building to 1 to 3 feet.
.WEDNESDAY...North winds 15 to 25 knots becoming northwest 20 to
30 knots by mid afternoon. A chance of showers. A slight chance
of thunderstorms by mid afternoon. Waves building to 3 to 5 feet
occasionally to 7 feet.
.WEDNESDAY NIGHT...Northwest winds 15 to 25 knots. A chance of
showers. Waves subsiding to 2 to 4 feet.
.THURSDAY...West winds 10 to 20 knots. A chance of showers. Waves
subsiding to calm to 2 feet.
.FRIDAY...Northwest winds 15 to 25 knots. Waves building to 1 to
3 feet.

$$

LSZ263-012000-
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-
1001 AM EDT Mon Sep 1 2025

.REST OF TODAY...Southwest winds 5 to 15 knots. Isolated showers
by late morning. Waves calm to 2 feet.
.TONIGHT...South winds 5 to 15 knots veering southwest after
midnight. Waves calm to 2 feet.
.TUESDAY...Southwest winds 5 to 15 knots increasing to 10 to
20 knots in the afternoon. A chance of showers and a slight
chance of thunderstorms by mid afternoon. Waves building to 1 to
3 feet, then subsiding to calm to 2 feet.
.TUESDAY NIGHT...Southwest winds 10 to 20 knots becoming north
15 to 25 knots after midnight. Showers and a chance of
thunderstorms. Waves building to 2 to 4 feet.
.WEDNESDAY...North winds 15 to 25 knots backing northwest by mid
afternoon. A slight chance of thunderstorms through early
afternoon. A chance of showers. Waves building to 3 to 6 feet
occasionally to 8 feet.
.WEDNESDAY NIGHT...Northwest winds 15 to 25 knots. A chance of
showers. Waves 3 to 6 feet occasionally to 8 feet.
.THURSDAY...West winds 15 to 25 knots diminishing to 10 to
20 knots. A chance of showers. Waves subsiding to 1 to 3 feet.
.FRIDAY...Northwest winds 15 to 25 knots. A chance of showers.
Waves building to 3 to 5 feet occasionally to 7 feet.

$$

LSZ264-012000-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
1001 AM EDT Mon Sep 1 2025

.REST OF TODAY...Southwest winds 5 to 15 knots. Waves calm to
2 feet.
.TONIGHT...South winds 5 to 15 knots veering southwest late.
Waves calm to 2 feet.
.TUESDAY...Southwest winds 5 to 15 knots increasing to 10 to
20 knots in the afternoon, then diminishing to 5 to 15 knots
late. A slight chance of showers and thunderstorms by mid
afternoon. Waves building to 1 to 3 feet, then subsiding to calm
to 2 feet.
.TUESDAY NIGHT...Southwest winds 5 to 15 knots becoming north
15 to 25 knots after midnight. Showers and a chance of
thunderstorms. Waves building to 3 to 5 feet occasionally to
7 feet.
.WEDNESDAY...North winds 20 to 30 knots becoming northwest 15 to
25 knots by mid 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.
.WEDNESDAY NIGHT...Northwest winds 15 to 25 knots diminishing to
10 to 20 knots after midnight. A chance of showers. Waves
subsiding to 3 to 5 feet occasionally to 7 feet.
.THURSDAY...West winds 15 to 25 knots. A chance of showers. Waves
subsiding to 1 to 3 feet.
.FRIDAY...Northwest winds 15 to 25 knots. Waves building to 3 to
5 feet occasionally to 7 feet.

$$

LSZ265-012000-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1001 AM EDT Mon Sep 1 2025

.REST OF TODAY...Southwest winds 5 to 15 knots backing south in
the afternoon, then becoming southeast 10 to 20 knots late.
Isolated showers and thunderstorms by mid afternoon. Waves calm
to 2 feet.
.TONIGHT...Southeast winds 5 to 15 knots veering southwest late.
Waves calm to 2 feet.
.TUESDAY...Southwest winds 5 to 15 knots backing south in the
afternoon, then becoming southeast 10 to 20 knots late. Waves
calm to 2 feet.
.TUESDAY NIGHT...Southwest winds 10 to 20 knots veering west
after midnight. A chance of showers through midnight. A chance of
thunderstorms. Showers likely after midnight. Waves calm to
2 feet.
.WEDNESDAY...Northwest winds 15 to 25 knots increasing to 20 to
30 knots by mid afternoon. Showers likely and a slight chance of
thunderstorms through early afternoon, then a chance of showers
by mid afternoon. Waves building to 3 to 5 feet occasionally to
7 feet.
.WEDNESDAY NIGHT...Northwest winds 20 to 30 knots diminishing to
15 to 25 knots after midnight. A chance of showers. Waves
subsiding to 2 to 4 feet.
.THURSDAY...West winds 20 to 30 knots becoming southwest 15 to
25 knots. A chance of showers. Waves subsiding to calm to 2 feet.
.FRIDAY...Northwest winds 15 to 25 knots. A chance of showers.
Waves calm to 2 feet.

$$

LSZ266-012000-
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-
1001 AM EDT Mon Sep 1 2025

.REST OF TODAY...Southwest winds 5 to 15 knots backing southeast
late. Waves calm to 2 feet.
.TONIGHT...South winds 5 to 15 knots increasing to 10 to 20 knots
after midnight. Waves calm to 2 feet.
.TUESDAY...Southwest winds 10 to 20 knots backing south in the
afternoon, then diminishing to 5 to 15 knots late. Waves calm to
2 feet.
.TUESDAY NIGHT...South winds 10 to 20 knots veering southwest
after midnight. A slight chance of showers through midnight. A
chance of thunderstorms. Showers likely after midnight. Waves
building to 2 to 4 feet.
.WEDNESDAY...Northwest winds 15 to 25 knots increasing to 20 to
30 knots by mid afternoon. Showers likely through early
afternoon. A slight chance of thunderstorms. A chance of showers
by mid afternoon. Waves building to 4 to 7 feet occasionally to
9 feet.
.WEDNESDAY NIGHT...Northwest winds 20 to 30 knots becoming west
15 to 25 knots after midnight. A chance of showers. Waves
subsiding to 3 to 6 feet occasionally to 8 feet.
.THURSDAY...West winds 20 to 30 knots diminishing to 15 to
25 knots. A chance of showers. Waves subsiding to 2 to 4 feet.
.FRIDAY...Northwest winds 10 to 20 knots increasing to 15 to
25 knots. A chance of showers. Waves subsiding to 1 to 3 feet,
then building to 3 to 5 feet occasionally to 7 feet.

$$

LSZ267-012000-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1001 AM EDT Mon Sep 1 2025

.REST OF TODAY...South winds 10 to 20 knots diminishing to 5 to
15 knots in the afternoon, then backing southeast late. Waves
calm to 2 feet.
.TONIGHT...South winds 5 to 15 knots increasing to 10 to 20 knots
after midnight. Waves calm to 2 feet.
.TUESDAY...South winds 10 to 20 knots diminishing to 5 to
15 knots in the afternoon, then backing southeast late. Waves
calm to 2 feet.
.TUESDAY NIGHT...South winds 10 to 20 knots increasing to 15 to
25 knots after midnight. A chance of showers and a slight chance
of thunderstorms after midnight. Waves building to 1 to 3 feet.
.WEDNESDAY...South winds 15 to 25 knots becoming west 20 to
30 knots by mid afternoon. Showers and a chance of thunderstorms.
Waves building to 3 to 6 feet occasionally to 8 feet.
.WEDNESDAY NIGHT...West winds 15 to 25 knots. A chance of
showers. Waves subsiding to 3 to 5 feet occasionally to 7 feet.
.THURSDAY...West winds 20 to 30 knots becoming southwest 15 to
25 knots. A chance of showers. Waves building to 3 to 6 feet
occasionally to 8 feet, then subsiding to 2 to 4 feet.
.FRIDAY...West winds 15 to 25 knots veering northwest. Showers
likely, then a chance of showers. Waves subsiding to 1 to 3 feet,
then building to 3 to 5 feet occasionally to 7 feet.

$$

LSZ261-012000-
MAFOR 0115/
Superior West 13510 11400 11410 13510. Waves 2 feet or less.

Superior North Central 13510 12410 11500 12510. Waves 1 to 2
feet.

Superior South Central 11400 13300 12410 11510 11500. Waves 2
feet or less.

Superior East 11410 11400 11300 14410 11410. Waves 1 to 2 feet.

$$

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