476
FZUS63 KMQT 091402
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1001 AM EDT Thu Oct 9 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...

30.4 inch high pressure remains sprawled out over the Great Lakes
today, shifting east to New England by this evening at 30.5 inches.
This allows a 30.0 inch trough to move into the Upper Great Lakes as
a 29.4 inch low moves over Hudson Bay. Along this trough, a 29.9
inch low will develop near Thunder Bay, then move over Lake Superior
Friday afternoon and evening. The low continues into Lake Michigan
Friday night and Saturday while 30.1 inch ridging builds over the
lake. This ridge gradually weakens through the weekend as the next
system organizes upstream in the Northern Plains.


LSZ162-092000-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1001 AM EDT Thu Oct 9 2025 /901 AM CDT Thu Oct 9 2025/

.REST OF TODAY...South winds 10 to 20 knots. Waves 1 to 3 feet.
.TONIGHT...South winds 15 to 25 knots increasing to 20 to
30 knots after midnight, then becoming southwest 15 to 25 knots
late. A chance of showers. Waves building to 3 to 6 feet
occasionally to 8 feet.
.FRIDAY...Northwest winds 20 to 30 knots diminishing to 15 to
25 knots late. A chance of showers. Waves subsiding to 1 to
3 feet.
.FRIDAY NIGHT...North winds 10 to 20 knots. A slight chance of
showers through midnight. Waves 1 to 3 feet.
.SATURDAY...East winds 5 to 15 knots increasing to 10 to 20 knots
by mid afternoon. Waves subsiding to calm to 2 feet.
.SATURDAY NIGHT...East winds 10 to 20 knots veering southeast
after midnight. Waves building to 2 to 4 feet.
.SUNDAY...Southeast winds 15 to 25 knots becoming south 20 to
30 knots. A chance of showers, then showers likely. Waves
building to 3 to 6 feet occasionally to 8 feet.
.MONDAY...Southwest winds 20 to 30 knots becoming west 10 to
20 knots. A chance of showers. Waves subsiding to 1 to 3 feet.

$$

LSZ263-092000-
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 Thu Oct 9 2025

.REST OF TODAY...South winds 10 to 20 knots increasing to 15 to
25 knots in the afternoon, then diminishing to 10 to 20 knots
late. Waves 1 to 3 feet building to 2 to 4 feet, then subsiding
to 1 to 3 feet.
.TONIGHT...South winds 20 to 30 knots. Showers likely. Waves
building to 3 to 6 feet occasionally to 8 feet.
.FRIDAY...West winds 20 to 30 knots veering northwest in the
afternoon. A slight chance of thunderstorms through early
afternoon. Showers likely. Waves building to 4 to 7 feet
occasionally to 9 feet, then subsiding to 3 to 6 feet
occasionally to 8 feet.
.FRIDAY NIGHT...North winds 15 to 25 knots veering northeast
after midnight. A slight chance of showers through midnight.
Waves subsiding to 2 to 4 feet.
.SATURDAY...East winds 10 to 20 knots diminishing to 5 to
15 knots by mid afternoon. Waves subsiding to calm to 2 feet.
.SATURDAY NIGHT...Southeast winds 10 to 20 knots. Waves building
to 2 to 4 feet.
.SUNDAY...Southeast gales to 35 knots veering south. Showers
likely. Waves building to 4 to 7 feet occasionally to 9 feet.
.MONDAY...Southwest gales to 35 knots becoming west 20 to
30 knots. A chance of showers. Waves subsiding to 3 to 5 feet
occasionally to 7 feet.

$$

LSZ264-092000-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
1001 AM EDT Thu Oct 9 2025

.REST OF TODAY...Southwest winds 10 to 20 knots backing south in
the afternoon. Waves 1 to 3 feet building to 2 to 4 feet, then
subsiding to 1 to 3 feet.
.TONIGHT...South winds 15 to 25 knots becoming southwest 20 to
30 knots after midnight, then becoming south 15 to 25 knots late.
A slight chance of showers through midnight, then showers after
midnight. Waves building to 3 to 6 feet occasionally to 8 feet.
.FRIDAY...Southwest winds 20 to 30 knots veering west in the
afternoon, then veering north late. A slight chance of
thunderstorms through early afternoon. Showers. Waves building to
4 to 7 feet occasionally to 9 feet, then subsiding to 3 to 5 feet
occasionally to 7 feet.
.FRIDAY NIGHT...North winds 15 to 25 knots becoming northeast
10 to 20 knots after midnight. A slight chance of showers through
midnight. Waves subsiding to 2 to 4 feet.
.SATURDAY...East winds 10 to 20 knots diminishing to 5 to
15 knots by mid afternoon. Waves subsiding to calm to 2 feet.
.SATURDAY NIGHT...Southeast winds 5 to 15 knots increasing to
10 to 20 knots after midnight. Waves building to 2 to 4 feet.
.SUNDAY...Southeast gales to 35 knots veering south. A chance of
showers. Waves building to 7 to 10 feet occasionally to 13 feet.
.MONDAY...South gales to 35 knots becoming west 20 to 30 knots. A
chance of showers. Waves subsiding to 3 to 6 feet occasionally to
8 feet.

$$

LSZ265-092000-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1001 AM EDT Thu Oct 9 2025

.REST OF TODAY...Southwest winds 10 to 20 knots becoming south
15 to 25 knots in the afternoon. Waves calm to 2 feet building to
1 to 3 feet.
.TONIGHT...South winds 20 to 30 knots. Showers after midnight.
Waves building to 3 to 5 feet occasionally to 7 feet, then
subsiding to 2 to 4 feet.
.FRIDAY...Southwest winds 20 to 30 knots veering northwest late.
A slight chance of thunderstorms through early afternoon.
Showers. Waves subsiding to 1 to 3 feet.
.FRIDAY NIGHT...North winds 15 to 25 knots veering northeast
after midnight. A chance of showers. Waves building to 2 to
4 feet.
.SATURDAY...East winds 10 to 20 knots. Waves subsiding to calm to
2 feet.
.SATURDAY NIGHT...Southeast winds 10 to 20 knots. Waves calm to
2 feet.
.SUNDAY...Southeast winds 20 to 30 knots increasing to gales to
35 knots. A chance of showers. Waves building to 3 to 6 feet
occasionally to 8 feet.
.MONDAY...South gales to 35 knots becoming west 20 to 30 knots.
Showers likely. Waves subsiding to calm to 2 feet.

$$

LSZ266-092000-
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 Thu Oct 9 2025

.REST OF TODAY...South winds 10 to 20 knots increasing to 15 to
25 knots in the afternoon. Waves 2 to 4 feet.
.TONIGHT...South winds 20 to 30 knots increasing to 30 knots with
a few gale force gusts to 35 knots possible after midnight.
Showers after midnight. Waves building to 4 to 7 feet
occasionally to 9 feet.
.FRIDAY...South winds 20 to 30 knots veering southwest in the
afternoon, then becoming west 15 to 25 knots late. A slight
chance of thunderstorms through early afternoon. Showers. Waves
building to 5 to 8 feet occasionally to 10 feet, then subsiding
to 3 to 5 feet occasionally to 7 feet.
.FRIDAY NIGHT...Northeast winds 15 to 25 knots. A chance of
showers. Waves subsiding to 2 to 4 feet.
.SATURDAY...East winds 10 to 20 knots. A slight chance of showers
through early afternoon. Waves subsiding to calm to 2 feet.
.SATURDAY NIGHT...Southeast winds 5 to 15 knots increasing to
10 to 20 knots after midnight. Waves building to 1 to 3 feet.
.SUNDAY...Southeast winds 20 to 30 knots increasing to gales to
35 knots. A chance of showers. Waves building to 7 to 10 feet
occasionally to 13 feet.
.MONDAY...South gales to 35 knots becoming west 15 to 25 knots.
Showers likely. Waves subsiding to 3 to 6 feet occasionally to
8 feet.

$$

LSZ267-092000-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1001 AM EDT Thu Oct 9 2025

.REST OF TODAY...South winds 10 to 20 knots increasing to 15 to
25 knots late. Waves 1 to 3 feet.
.TONIGHT...South winds 15 to 25 knots increasing to 20 to
30 knots after midnight. A chance of showers after midnight.
Waves building to 3 to 6 feet occasionally to 8 feet.
.FRIDAY...South winds 20 to 30 knots diminishing to 15 to
25 knots late. Showers. Waves building to 4 to 7 feet
occasionally to 9 feet, then subsiding to 3 to 5 feet
occasionally to 7 feet.
.FRIDAY NIGHT...East winds 15 to 25 knots backing northeast after
midnight. Showers likely through midnight, then a slight chance
of showers after midnight. Waves subsiding to 2 to 4 feet.
.SATURDAY...East winds 10 to 20 knots. A slight chance of showers
by mid afternoon. Waves subsiding to calm to 2 feet.
.SATURDAY NIGHT...East winds 10 to 20 knots becoming southeast
15 to 25 knots after midnight. Waves building to 1 to 3 feet.
.SUNDAY...Southeast winds 15 to 25 knots increasing to 20 to
30 knots. A chance of showers. Waves building to 3 to 6 feet
occasionally to 8 feet.
.MONDAY...South winds 15 to 25 knots veering west. Showers
likely, then a chance of showers. Waves subsiding to 2 to 4 feet,
then building to 3 to 5 feet occasionally to 7 feet.

$$

LSZ261-092000-
MAFOR 0915/
Superior West 11420 11410 11420 11430 11446 12540 11640. Waves 1
to 3 feet this afternoon. Waves 1 to 2 feet building to 3 to 5
feet tonight. Waves 3 to 6 feet Friday morning.

Superior North Central 11520 12420 12430 11536 11436 11546. Waves
1 to 3 feet building to 2 to 4 feet this afternoon. Waves 2 to 4
feet building to 3 to 6 feet tonight. Waves 3 to 6 feet Friday
morning.

Superior South Central 12420 12430 11440 11430 11446 11546. Waves
1 to 3 feet this afternoon. Waves 2 to 4 feet building to 3 to 5
feet tonight. Waves 3 to 6 feet Friday morning.

Superior East 12420 11430 14440 11446. Waves 2 to 4 feet this
afternoon. Waves 2 to 4 feet building to 4 to 7 feet tonight.
Waves 5 to 8 feet Friday morning.

$$

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