092
FZUS63 KMQT 022001
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
401 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-
401 PM EDT Tue Sep 2 2025 /301 PM CDT Tue Sep 2 2025/

.LATE THIS AFTERNOON...Southwest winds 10 to 20 knots. A chance
of showers and thunderstorms. Waves calm to 2 feet.
.TONIGHT...West winds 10 to 20 knots becoming northwest 15 to
25 knots after midnight, then increasing to 20 to 30 knots late.
Showers likely and a chance of thunderstorms through midnight,
then a slight chance of showers after midnight. Waves 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 thunderstorms
by mid afternoon. 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-
401 PM EDT Tue Sep 2 2025

.LATE THIS AFTERNOON...Southwest winds 10 to 20 knots. A chance
of showers and thunderstorms. Waves 1 to 3 feet.
.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 through midnight. A chance of thunderstorms.
A chance of showers after midnight. Waves 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 rain
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 rain 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 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-
401 PM EDT Tue Sep 2 2025

.LATE THIS AFTERNOON...South winds 5 to 15 knots. A chance of
showers and a slight chance of thunderstorms. Waves 1 to 3 feet
subsiding to calm to 2 feet.
.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 chance of thunderstorms. Waves 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. 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-
401 PM EDT Tue Sep 2 2025

.LATE THIS AFTERNOON...Southeast winds 10 to 20 knots. A slight
chance of showers and thunderstorms. Waves calm to 2 feet.
.TONIGHT...Southwest winds 10 to 20 knots becoming west 15 to
25 knots late. Showers likely and a chance of thunderstorms.
Waves 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. A slight chance of thunderstorms
through early afternoon. Showers likely. 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. 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-
401 PM EDT Tue Sep 2 2025

.LATE THIS AFTERNOON...South winds 10 to 20 knots. A slight
chance of showers. Waves calm to 2 feet.
.TONIGHT...South winds 10 to 20 knots increasing to 15 to
25 knots after midnight, then veering southwest late. A chance of
showers through midnight. A chance of thunderstorms. Showers
likely after midnight. Waves 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 and a slight chance of
thunderstorms through early afternoon, then 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. 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 3 to 6 feet
occasionally to 8 feet.
.FRIDAY NIGHT...West winds 15 to 25 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.
.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-
401 PM EDT Tue Sep 2 2025

.LATE THIS AFTERNOON...Southeast winds 10 to 20 knots. Waves calm
to 2 feet.
.TONIGHT...South winds 15 to 25 knots. A chance of showers and
thunderstorms after midnight. Waves 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 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 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.

$$

LSZ261-030200-
MAFOR 0221/
Superior West 11520 11526 11626 14730 11730. A chance of
thunderstorms this evening. Waves 1 to 2 feet building to 3 to 6
feet tonight. Waves 3 to 6 feet Wednesday.

Superior North Central 12410 11516 11636 11756 11750 12746. A
chance of thunderstorms this evening. Waves 1 to 3 feet building
to 3 to 6 feet tonight. Waves 7 to 10 feet Wednesday.

Superior South Central 12420 11426 11526 11636 11746 11740 11746.
A chance of thunderstorms tonight and Wednesday morning. Waves 1
to 3 feet building to 2 to 4 feet tonight. Waves 3 to 5 feet
building to 8 to 11 feet Wednesday.

Superior East 11320 12430 11420 11526 11536 11640 11740. A chance
of thunderstorms overnight and Wednesday morning. Waves 1 to 3
feet building to 3 to 6 feet tonight. Waves 3 to 6 feet building
to 5 to 9 feet Wednesday.

$$

WFO MQT

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