235
FZUS63 KMQT 010801
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
401 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...

30.2 inch high pressure remains sprawled out over the Great Lakes
through today. A 29.8 inch low looks to move near or over Lake
Superior Tuesday evening; expect the low to progressively deepen to
around 29.5 inches Wednesday as it lifts out of Lake Superior
towards James Bay, eventually arriving Thursday morning. This low
then deepens to 29.2 inches by Friday morning as it retrogrades to
the southern shoreline of Hudson Bay before progressively weakening
to 29.5 inches again by Saturday as it spins back into northern
Ontario before lifting into far northern Quebec.


LSZ162-012000-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
401 AM EDT Mon Sep 1 2025 /301 AM CDT Mon Sep 1 2025/

.EARLY THIS MORNING...Southwest winds 5 to 15 knots. Isolated
showers and thunderstorms. Waves calm to 2 feet.
.TODAY...Southwest winds 5 to 15 knots. Isolated showers and
thunderstorms through early afternoon. 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. 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-
401 AM EDT Mon Sep 1 2025

.EARLY THIS MORNING...Southwest winds 5 to 15 knots. Isolated
showers and thunderstorms. Waves calm to 2 feet.
.TODAY...Southwest winds 5 to 15 knots. Isolated showers and
thunderstorms through early afternoon. 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.
.TUESDAY NIGHT...Southwest winds 10 to 20 knots becoming north
15 to 25 knots after midnight. Showers and a chance of
thunderstorms. Waves subsiding to calm to 2 feet, then building
to 2 to 4 feet.
.WEDNESDAY...North winds 15 to 25 knots backing northwest by mid
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-
401 AM EDT Mon Sep 1 2025

.EARLY THIS MORNING...Southwest winds 5 to 15 knots. Waves calm
to 2 feet.
.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.
.TUESDAY NIGHT...Southwest winds 5 to 15 knots becoming north
15 to 25 knots after midnight. Showers and a chance of
thunderstorms. Waves subsiding to calm to 2 feet, then 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-
401 AM EDT Mon Sep 1 2025

.EARLY THIS MORNING...West winds 5 to 15 knots. Waves calm to
2 feet.
.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 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-
401 AM EDT Mon Sep 1 2025

.EARLY THIS MORNING...South winds 5 to 15 knots. Waves calm to
2 feet.
.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 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-
401 AM EDT Mon Sep 1 2025

.EARLY THIS MORNING...South winds 10 to 20 knots. Waves calm to
2 feet.
.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.

$$

LSZ261-011400-
MAFOR 0109/
Superior West 14510 11510 11400 11410 11510. Waves 2 feet or
less.

Superior North Central 11500 14510 12410 11500. Waves 1 to 2
feet.

Superior South Central 12500 11400 13300 12410. Waves 2 feet or
less.

Superior East 13410 11400 11300 13410. 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