725
FZUS63 KMQT 030201
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1001 PM EDT Tue Sep 2 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 29.9 inch trough deepens to 29.7 inches tonight over northern Lake
Superior. It further deepens to 29.5 inches Wednesday morning as it
lifts into Ontario. Thursday, the low will retrograde westward over
far northern Ontario as it deepens to 29.3 inches. While this low
remains in place Thursday night, a quick moving low will move
through Wisconsin at 29.4 inches. This low will lift northeast into
Ontario by Friday afternoon, then to near James Bay Friday night
while consolidating with the northern Ontario low. The low shifts
northeast through northern Quebec on Saturday as 30.1 inch high
pressure moves into the Midwest for the weekend, strengthening to
30.3 inches over the Lower Midwest on Sunday.


LSZ162-030800-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1001 PM EDT Tue Sep 2 2025 /901 PM CDT Tue Sep 2 2025/

.REST OF TONIGHT...West winds 10 to 20 knots becoming northwest
15 to 25 knots after midnight, then increasing to 20 to 30 knots
late. A slight chance of thunderstorms by midnight. A chance of
showers. Waves 1 to 3 feet building to 3 to 6 feet occasionally
to 8 feet.
.WEDNESDAY...North winds 20 to 30 knots backing northwest in the
afternoon. A chance of showers. A slight chance of waterspouts by
mid afternoon. Waves 3 to 6 feet occasionally to 8 feet.
.WEDNESDAY NIGHT...Northwest winds 20 to 30 knots diminishing to
15 to 25 knots after midnight. A slight chance of waterspouts. A
chance of showers. Waves subsiding to 3 to 6 feet occasionally to
8 feet.
.THURSDAY...West winds 15 to 25 knots. A slight chance of
waterspouts through early afternoon. A chance of showers. Waves
subsiding to 2 to 4 feet.
.THURSDAY NIGHT...West winds 10 to 20 knots veering northwest
after midnight. A chance of showers. Waves subsiding to calm to
2 feet, then building to 1 to 3 feet.
.FRIDAY...West winds 20 to 30 knots. A chance of showers. Waves
building to 3 to 5 feet occasionally to 7 feet.
.FRIDAY NIGHT...West winds 15 to 25 knots veering northwest after
midnight. Waves subsiding to 2 to 4 feet.
.SATURDAY...West winds 15 to 25 knots becoming northwest 10 to
20 knots. Waves subsiding to calm to 2 feet.
.SUNDAY...Southwest winds 10 to 20 knots. Waves calm to 2 feet.

$$

LSZ263-030800-
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 PM EDT Tue Sep 2 2025

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

$$

LSZ264-030800-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
1001 PM EDT Tue Sep 2 2025

.REST OF TONIGHT...South winds 5 to 15 knots becoming southwest
10 to 20 knots after midnight, then becoming northwest to
30 knots with a few gale force gusts to 35 knots possible late.
Showers likely and a slight chance of thunderstorms. Waves 1 to
3 feet building to 6 to 9 feet occasionally to 11 feet.
.WEDNESDAY...North winds 20 to 30 knots backing northwest in the
afternoon. A chance of showers through early afternoon, then
showers likely by mid afternoon. A slight chance of waterspouts
by mid afternoon. Waves building to 7 to 10 feet occasionally to
13 feet.
.WEDNESDAY NIGHT...Northwest winds 20 to 30 knots diminishing to
15 to 25 knots after midnight. A slight chance of waterspouts.
Showers likely and a slight chance of thunderstorms. Waves
subsiding to 5 to 8 feet occasionally to 10 feet.
.THURSDAY...West winds 15 to 25 knots. A slight chance of
waterspouts through early afternoon. A chance of showers. Waves
subsiding to 3 to 6 feet occasionally to 8 feet.
.THURSDAY NIGHT...West winds 10 to 20 knots. A chance of showers
through midnight. A slight chance of thunderstorms. Showers
likely after midnight. Waves subsiding to 1 to 3 feet.
.FRIDAY...Northwest winds 20 to 30 knots becoming west gales to
35 knots by mid afternoon. A chance of showers. Waves building to
5 to 8 feet occasionally to 10 feet.
.FRIDAY NIGHT...West winds 20 to 30 knots becoming northwest
15 to 25 knots after midnight. Waves subsiding to 3 to 6 feet
occasionally to 8 feet.
.SATURDAY...Northwest winds 15 to 25 knots diminishing to 10 to
20 knots. Waves subsiding to 1 to 3 feet.
.SUNDAY...Northwest winds 10 to 20 knots becoming southwest 5 to
15 knots. Waves subsiding to calm to 2 feet.

$$

LSZ265-030800-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1001 PM EDT Tue Sep 2 2025

.REST OF TONIGHT...South winds 10 to 20 knots veering southwest
after midnight, then becoming west 15 to 25 knots late. Showers
likely and a chance of thunderstorms. Waves calm to 2 feet
building to 3 to 5 feet occasionally to 7 feet.
.WEDNESDAY...Northwest winds to 30 knots with a few gale force
gusts to 35 knots possible. Showers likely and a slight chance of
thunderstorms. A slight chance of waterspouts by mid afternoon.
Waves building to 5 to 8 feet occasionally to 10 feet.
.WEDNESDAY NIGHT...Northwest winds 20 to 30 knots. A slight
chance of waterspouts. Showers likely and a slight chance of
thunderstorms. Waves subsiding to 4 to 7 feet occasionally to
9 feet.
.THURSDAY...West winds 20 to 30 knots diminishing to 15 to
25 knots by mid afternoon. A slight chance of waterspouts through
early afternoon. Showers likely through early afternoon, then a
slight chance of showers by mid afternoon. Waves subsiding to
2 to 4 feet.
.THURSDAY NIGHT...Southwest winds 10 to 20 knots. A chance of
showers through midnight. A slight chance of thunderstorms.
Showers likely after midnight. Waves subsiding to calm to 2 feet.
.FRIDAY...West winds 15 to 25 knots increasing to gales to
35 knots by mid afternoon. Showers likely through early
afternoon, then a chance of showers by mid afternoon. Waves
building to 2 to 4 feet.
.FRIDAY NIGHT...West winds 20 to 30 knots diminishing to 15 to
25 knots after midnight. A chance of showers. Waves subsiding to
1 to 3 feet.
.SATURDAY...Northwest winds 15 to 25 knots diminishing to 10 to
20 knots. Waves subsiding to calm to 2 feet.
.SUNDAY...Northwest winds 10 to 20 knots becoming southwest 5 to
15 knots. Waves calm to 2 feet.

$$

LSZ266-030800-
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 PM EDT Tue Sep 2 2025

.REST OF TONIGHT...South winds 10 to 20 knots increasing to 15 to
25 knots after midnight, then veering southwest late. A chance of
showers by midnight. A chance of thunderstorms. Showers likely
after midnight. Waves 3 to 5 feet occasionally to 7 feet building
to 5 to 8 feet occasionally to 10 feet.
.WEDNESDAY...Northwest winds 20 to 30 knots increasing to
30 knots with a few gale force gusts to 35 knots possible in the
afternoon. A chance of showers through early afternoon. A slight
chance of thunderstorms. Showers likely by mid afternoon. Waves
building to 8 to 11 feet occasionally to 14 feet.
.WEDNESDAY NIGHT...Northwest winds to 30 knots with a few gale
force gusts to 35 knots possible diminishing to 20 to 30 knots
after midnight, then backing west late. A slight chance of
waterspouts. Showers likely and a slight chance of thunderstorms.
Waves subsiding to 6 to 9 feet occasionally to 11 feet.
.THURSDAY...West winds 20 to 30 knots. A slight chance of
waterspouts through early afternoon. Showers likely through early
afternoon, then a chance of showers by mid afternoon. Waves
subsiding to 4 to 7 feet occasionally to 9 feet.
.THURSDAY NIGHT...Southwest winds 10 to 20 knots. A chance of
showers through midnight. A slight chance of thunderstorms.
Showers likely after midnight. Waves subsiding to 1 to 3 feet.
.FRIDAY...West 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 4 to 7 feet
occasionally to 9 feet.
.FRIDAY NIGHT...West winds 15 to 25 knots. A chance of showers.
Waves subsiding to 3 to 6 feet occasionally to 8 feet.
.SATURDAY...Northwest winds 15 to 25 knots diminishing to 10 to
20 knots. A chance of showers. Waves subsiding to 1 to 3 feet.
.SUNDAY...Northwest winds 10 to 20 knots becoming southwest 5 to
15 knots. Waves subsiding to calm to 2 feet.

$$

LSZ267-030800-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1001 PM EDT Tue Sep 2 2025

.REST OF TONIGHT...South winds 15 to 25 knots. A chance of
showers and thunderstorms after midnight. Waves 2 to 4 feet
building to 3 to 5 feet occasionally to 7 feet.
.WEDNESDAY...Southwest winds 15 to 25 knots becoming west 20 to
30 knots in the afternoon, then veering northwest late. Showers
and a chance of thunderstorms through early afternoon, then a
chance of showers by mid afternoon. Waves building to 7 to
10 feet occasionally to 13 feet.
.WEDNESDAY NIGHT...Northwest winds 20 to 30 knots backing west
after midnight. A chance of showers through midnight. A slight
chance of thunderstorms. Showers likely after midnight. A slight
chance of waterspouts after midnight. Waves subsiding to 6 to
9 feet occasionally to 11 feet.
.THURSDAY...West winds 20 to 30 knots. A slight chance of
waterspouts through early afternoon. Showers likely through early
afternoon, then a chance of showers and a slight chance of
thunderstorms by mid afternoon. Waves subsiding to 4 to 7 feet
occasionally to 9 feet.
.THURSDAY NIGHT...Southwest winds 10 to 20 knots backing south
after midnight. A chance of showers through midnight, then
showers and a slight chance of thunderstorms after midnight.
Waves subsiding to 2 to 4 feet.
.FRIDAY...West winds 15 to 25 knots increasing to 20 to 30 knots
by mid afternoon. Showers through early afternoon. A chance of
showers by mid afternoon. Waves building to 4 to 7 feet
occasionally to 9 feet.
.FRIDAY NIGHT...West winds 20 to 30 knots diminishing to 15 to
25 knots after midnight. Showers likely through midnight, then a
chance of showers after midnight. Waves building to 5 to 8 feet
occasionally to 10 feet, then subsiding to 3 to 6 feet
occasionally to 8 feet.
.SATURDAY...West winds 15 to 25 knots veering northwest. A chance
of showers. Waves subsiding to 1 to 3 feet.
.SUNDAY...Northwest winds 10 to 20 knots backing southwest. Waves
subsiding to calm to 2 feet.

$$

LSZ261-030800-
MAFOR 0303/
Superior West 11626 14730 11730 11740 11730. Waves 2 to 4 feet
building to 3 to 6 feet overnight. Waves 3 to 6 feet Wednesday
and Wednesday evening.

Superior North Central 11516 11636 11756 11750 14746. A chance of
thunderstorms overnight. Waves 2 to 4 feet building to 3 to 6
feet overnight. Waves 6 to 10 feet Wednesday and Wednesday
evening.

Superior South Central 11426 11526 11636 11746 11740 13746. A
chance of thunderstorms overnight. Waves 2 to 4 feet overnight.
Waves 3 to 5 feet building to 8 to 11 feet Wednesday. Waves 7 to
10 feet Wednesday evening.

Superior East 11430 11420 11526 11536 11640 13740. A chance of
thunderstorms overnight and Wednesday morning. Waves 3 to 6 feet
overnight. Waves 3 to 6 feet building to 5 to 9 feet Wednesday.
Waves 6 to 10 feet Wednesday evening.

$$

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