588
FZUS63 KMQT 311401
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1001 AM EDT Sun Aug 31 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 30.2 inch high remains over the Great Lakes today, merging with
another high of 30.2 inches over the Northeast US by Monday. A 29.8
inch low looks to move near or over Lake Superior late
Tuesday/Tuesday night; expect the low to progressively deepen to
around 29.5 inches Wednesday. On Wednesday and Thursday, this low
lifts north toward James Bay then retrogrades northwestward
over northern Ontario before lifting into Hudson Bay late Friday.


LSZ162-312000-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1001 AM EDT Sun Aug 31 2025 /901 AM CDT Sun Aug 31 2025/

.REST OF TODAY...Southwest winds 5 to 15 knots. Waves calm to
2 feet.
.TONIGHT...South winds 5 to 15 knots veering southwest after
midnight. A slight chance of showers and thunderstorms after
midnight. Waves calm to 2 feet.
.MONDAY...Southwest winds 5 to 15 knots. A slight chance of
showers and thunderstorms through early afternoon. Waves calm to
2 feet.
.MONDAY NIGHT...Southwest winds 5 to 15 knots. Waves calm to
2 feet.
.TUESDAY...Southwest winds 5 to 15 knots increasing to 10 to
20 knots by mid afternoon. A chance of showers. A slight chance
of thunderstorms by mid afternoon. Waves calm to 2 feet.
.TUESDAY NIGHT...West 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. A chance of showers.
Waves 2 to 4 feet.
.THURSDAY...Northwest winds 15 to 25 knots becoming west 10 to
20 knots. A chance of showers. Waves subsiding to calm to 2 feet,
then building to 1 to 3 feet.

$$

LSZ263-312000-
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 Sun Aug 31 2025

.REST OF TODAY...Southwest winds 5 to 15 knots. Patchy fog by
late morning. Waves calm to 2 feet.
.TONIGHT...South winds 5 to 15 knots veering southwest late. A
slight chance of showers and thunderstorms after midnight. Waves
calm to 2 feet.
.MONDAY...Southwest winds 5 to 15 knots. A slight chance of
showers through early afternoon. Waves calm to 2 feet.
.MONDAY NIGHT...Southwest winds 5 to 15 knots. Waves calm to
2 feet.
.TUESDAY...Southwest winds 10 to 20 knots. A chance of showers
and a slight chance of thunderstorms by mid afternoon. Waves
building to 1 to 3 feet.
.TUESDAY NIGHT...West winds 10 to 20 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. 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.
.THURSDAY...Northwest winds 15 to 25 knots becoming west 10 to
20 knots. A chance of showers. Waves subsiding to 2 to 4 feet.

$$

LSZ264-312000-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
1001 AM EDT Sun Aug 31 2025

.REST OF TODAY...Southwest winds 5 to 15 knots becoming south
less than 10 knots late. Patchy fog. Waves calm to 2 feet.
.TONIGHT...South winds 5 to 15 knots becoming southwest less than
10 knots late. Patchy fog. Waves calm to 2 feet.
.MONDAY...Southwest winds 5 to 15 knots. Waves calm to 2 feet.
.MONDAY NIGHT...Southwest winds 5 to 15 knots. Waves calm to
2 feet.
.TUESDAY...Southwest winds 5 to 15 knots increasing to 10 to
20 knots by mid afternoon. A slight chance of showers and
thunderstorms by mid afternoon. Waves calm to 2 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots becoming north 15 to
25 knots after midnight. A chance of showers through midnight. A
chance of thunderstorms. Showers after midnight. Waves building
to 2 to 4 feet.
.WEDNESDAY...North winds 20 to 30 knots. 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.
.THURSDAY...Northwest winds 15 to 25 knots becoming west 10 to
20 knots. A chance of showers. Waves subsiding to 2 to 4 feet.

$$

LSZ265-312000-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1001 AM EDT Sun Aug 31 2025

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

$$

LSZ266-312000-
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 Sun Aug 31 2025

.REST OF TODAY...Southwest winds 5 to 15 knots backing south in
the afternoon, then backing east late. Waves calm to 2 feet.
.TONIGHT...Southeast winds 5 to 15 knots veering south after
midnight. Waves calm to 2 feet.
.MONDAY...South winds 5 to 15 knots. Waves calm to 2 feet.
.MONDAY NIGHT...South winds 5 to 15 knots veering southwest after
midnight. Waves calm to 2 feet.
.TUESDAY...Southwest winds 5 to 15 knots backing south by mid
afternoon. A slight chance of showers and thunderstorms by mid
afternoon. Waves calm to 2 feet.
.TUESDAY NIGHT...South winds 10 to 20 knots veering southwest
after midnight. A chance of showers. Waves building to 2 to
4 feet.
.WEDNESDAY...Northwest winds 20 to 30 knots. Showers likely, then
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.
.THURSDAY...Northwest winds 15 to 25 knots becoming west 10 to
20 knots. A chance of showers. Waves subsiding to 2 to 4 feet.

$$

LSZ267-312000-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1001 AM EDT Sun Aug 31 2025

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

$$

LSZ261-312000-
MAFOR 3115/
Superior West 13510 12400 12500 11510. Waves 2 feet or less.

Superior North Central 11510 11500 14400 12500. Waves around 1
foot.

Superior South Central 11400 11300 11200 12300 13500. Waves 1
foot or less.

Superior East 12400 11200 12300 13400. Waves 1 foot or less.

$$

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