174
FZUS63 KMQT 241401
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1001 AM EDT Sun Aug 24 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...

29.4 inch low pressure over James Bay this morning with a 29.8 inch
trough extending down over Lake Superior continues to spin near
James Bay and northern Quebec through Monday while weakening to 29.6
inches. As this happens, 30.2 inch high pressure stretches over the
Great Plains early next week, eventually bringing ridging of at
least 30.1 inches back over the western portions of Lake Superior
Monday and Tuesday. High pressure of 30.2 inches remains over the
Lower Midwest Wednesday, though a 29.9 inch trough is projected to
drop south over Lake Superior Wednesday evening. Behind the trough,
a 30.3 inch high drops down over northern Ontario Thursday and
arrives over the Upper Great Lakes by Friday morning.


LSZ162-242000-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1001 AM EDT Sun Aug 24 2025 /901 AM CDT Sun Aug 24 2025/

.REST OF TODAY...Northwest winds 20 to 30 knots. A slight chance
of waterspouts. A chance of showers. Waves 3 to 6 feet
occasionally to 8 feet.
.TONIGHT...Northwest winds 15 to 25 knots becoming north 10 to
20 knots after midnight. Waves subsiding to 1 to 3 feet.
.MONDAY...Northwest winds 10 to 20 knots. Waves subsiding to calm
to 2 feet.
.MONDAY NIGHT...Northwest winds 5 to 15 knots. Waves calm to
2 feet.
.TUESDAY...Northwest winds 5 to 15 knots becoming southwest 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.TUESDAY NIGHT...Southwest winds 10 to 20 knots veering west
after midnight. Waves calm to 2 feet.
.WEDNESDAY...Southwest winds 15 to 25 knots becoming northeast
10 to 20 knots. Waves building to 2 to 4 feet, then subsiding to
calm to 2 feet.
.THURSDAY...East winds 10 to 20 knots diminishing to 5 to
15 knots. Waves calm to 2 feet.

$$

LSZ263-242000-
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 24 2025

.REST OF TODAY...Northwest winds 15 to 25 knots. A slight chance
of waterspouts. A chance of showers. Waves 3 to 6 feet
occasionally to 8 feet building to 4 to 7 feet occasionally to
9 feet, then subsiding to 3 to 6 feet occasionally to 8 feet.
.TONIGHT...Northwest winds 15 to 25 knots becoming north 10 to
20 knots after midnight, then increasing to 15 to 25 knots late.
Sprinkles. Waves subsiding to 3 to 5 feet occasionally to 7 feet.
.MONDAY...North winds 15 to 25 knots becoming northwest 10 to
20 knots in the afternoon, then backing west late. Waves
subsiding to calm to 2 feet.
.MONDAY NIGHT...Northwest winds 5 to 15 knots veering north after
midnight. Waves calm to 2 feet.
.TUESDAY...Northwest winds 5 to 15 knots becoming southwest 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.TUESDAY NIGHT...Southwest winds 10 to 20 knots veering west
after midnight. Waves building to 1 to 3 feet.
.WEDNESDAY...West winds 20 to 30 knots becoming northeast 10 to
20 knots. Waves building to 3 to 5 feet occasionally to 7 feet,
then subsiding to 1 to 3 feet.
.THURSDAY...Northeast winds 5 to 15 knots veering east. Waves
subsiding to calm to 2 feet.

$$

LSZ264-242000-
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 24 2025

.REST OF TODAY...Northwest winds 15 to 25 knots. A chance of
showers. Waves 3 to 6 feet occasionally to 8 feet building to
4 to 7 feet occasionally to 9 feet, then subsiding to 3 to 6 feet
occasionally to 8 feet.
.TONIGHT...Northwest winds 15 to 25 knots veering north after
midnight. Sprinkles through midnight. Waves building to 4 to
7 feet occasionally to 9 feet, then subsiding to 3 to 6 feet
occasionally to 8 feet.
.MONDAY...Northwest winds 15 to 25 knots diminishing to 10 to
20 knots in the afternoon. Waves subsiding to 1 to 3 feet.
.MONDAY NIGHT...Northwest winds 5 to 15 knots. Waves subsiding to
calm to 2 feet.
.TUESDAY...Northwest winds 5 to 15 knots becoming west 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots. Waves building to
1 to 3 feet.
.WEDNESDAY...West winds 20 to 30 knots becoming northeast 15 to
25 knots. A chance of showers. Waves building to 3 to 5 feet
occasionally to 7 feet, then subsiding to 1 to 3 feet.
.THURSDAY...Northeast winds 5 to 15 knots veering east. Waves
subsiding to calm to 2 feet.

$$

LSZ265-242000-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1001 AM EDT Sun Aug 24 2025

.REST OF TODAY...Northwest winds 20 to 30 knots. A chance of
waterspouts. A chance of showers. Waves 3 to 6 feet occasionally
to 8 feet.
.TONIGHT...Northwest winds 20 to 30 knots. A slight chance of
waterspouts. 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.
.MONDAY...Northwest winds 20 to 30 knots diminishing to 15 to
25 knots late. Waves subsiding to 1 to 3 feet.
.MONDAY NIGHT...Northwest winds 10 to 20 knots. Waves subsiding
to calm to 2 feet.
.TUESDAY...Northwest winds 10 to 20 knots. Waves calm to 2 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots. Waves calm to 2 feet.
.WEDNESDAY...West winds 15 to 25 knots diminishing to 10 to
20 knots. Waves calm to 2 feet.
.THURSDAY...Northeast winds 10 to 20 knots becoming east 5 to
15 knots. Waves calm to 2 feet.

$$

LSZ266-242000-
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 24 2025

.REST OF TODAY...Northwest winds 20 to 30 knots increasing to
30 knots with a few gale force gusts to 35 knots possible late. A
chance of waterspouts. A chance of showers. Waves 3 to 6 feet
occasionally to 8 feet building to 5 to 8 feet occasionally to
10 feet.
.TONIGHT...Northwest winds 20 to 30 knots. A slight chance of
waterspouts through midnight. A chance of showers. Waves building
to 5 to 9 feet occasionally to 11 feet.
.MONDAY...Northwest winds 15 to 25 knots increasing to 20 to
30 knots in the afternoon, then diminishing to 15 to 25 knots
late. Waves subsiding to 3 to 6 feet occasionally to 8 feet.
.MONDAY NIGHT...Northwest winds 10 to 20 knots veering north
after midnight. Waves subsiding to 1 to 3 feet.
.TUESDAY...North winds 10 to 20 knots backing northwest by mid
afternoon. Waves 1 to 3 feet.
.TUESDAY NIGHT...West winds 5 to 15 knots increasing to 10 to
20 knots after midnight. Waves subsiding to calm to 2 feet, then
building to 1 to 3 feet.
.WEDNESDAY...West winds 10 to 20 knots veering north. A chance of
showers. Waves building to 3 to 5 feet occasionally to 7 feet,
then subsiding to 1 to 3 feet.
.THURSDAY...Northeast winds 10 to 20 knots becoming east 5 to
15 knots. Waves subsiding to calm to 2 feet.

$$

LSZ267-242000-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1001 AM EDT Sun Aug 24 2025

.REST OF TODAY...Northwest winds 15 to 25 knots increasing to
20 to 30 knots late. A chance of showers. A slight chance of
waterspouts by mid afternoon. Waves 3 to 6 feet occasionally to
8 feet building to 5 to 8 feet occasionally to 10 feet.
.TONIGHT...Northwest winds 20 to 30 knots. A chance of showers.
Waves building to 5 to 9 feet occasionally to 11 feet.
.MONDAY...Northwest winds 15 to 25 knots increasing to 20 to
30 knots in the afternoon. Waves subsiding to 4 to 7 feet
occasionally to 9 feet.
.MONDAY NIGHT...Northwest winds 15 to 25 knots becoming north
10 to 20 knots after midnight. Waves subsiding to 1 to 3 feet.
.TUESDAY...Northwest winds 10 to 20 knots. Waves 1 to 3 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots. Waves subsiding to
calm to 2 feet.
.WEDNESDAY...West winds 10 to 20 knots. A chance of showers.
Waves building to 1 to 3 feet, then subsiding to calm to 2 feet.
.THURSDAY...Northeast winds 10 to 20 knots veering east. Waves
building to 1 to 3 feet, then subsiding to calm to 2 feet.

$$

LSZ261-242000-
MAFOR 2415/
Superior West 11740 14730 11820 11830 11820. Waves 3 to 6 feet
this afternoon. Waves 3 to 5 feet subsiding to 2 to 4 feet
tonight. Waves 2 to 4 feet Monday morning.

Superior North Central 13740 12730 11830 12730. A chance of
showers this afternoon. Waves 4 to 7 feet this afternoon and
tonight. Waves 4 to 7 feet subsiding to 3 to 6 feet Monday
morning.

Superior South Central 11730 11740 11746 12740 13730. A chance of
waterspouts this afternoon. Waves 5 to 8 feet this afternoon and
tonight. Waves 4 to 7 feet subsiding to 3 to 6 feet Monday
morning.

Superior East 12730 11740 12730 12740 11730. A chance of showers
this afternoon and tonight. Waves 5 to 8 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