947
FZUS63 KMQT 012001
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
401 PM EDT Mon Sep 1 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...

30.2 inch high pressure sprawled out over the Northeast is sending
ridging into the Great Lakes this afternoon. This feature continues
to weaken and slide eastward tonight into early Tuesday while a 30.0
inch trough drops out of Ontario deepening to 29.8 inches over Lake
Superior by the afternoon. The trough deepens to 29.6 inches by
Wednesday afternoon over the eastern half of the lake. By Thursday
morning, the trough will consolidate into a surface low of 29.4
inches over northeast Ontario. Thursday evening, the low will pivot
to far northeastern Ontario while a low of 29.5 inches moves into
Minnesota. The second low will pass near Lake Superior Friday at
around 29.5 inches before consolidating with the northern Ontario
low. The low will shift northeast as 30.1 inch high pressure moves
into the Midwest for the weekend.


LSZ162-020800-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
401 PM EDT Mon Sep 1 2025 /301 PM CDT Mon Sep 1 2025/

.LATE THIS AFTERNOON...Southwest winds 5 to 15 knots. A slight
chance of showers and thunderstorms. Waves calm to 2 feet.
.TONIGHT...South winds 5 to 15 knots veering southwest after
midnight. A slight chance of showers after midnight. Waves calm
to 2 feet.
.TUESDAY...Southwest winds 5 to 15 knots increasing to 10 to
20 knots in the afternoon. A chance of showers and thunderstorms.
Waves calm to 2 feet.
.TUESDAY NIGHT...Southwest winds 10 to 20 knots veering west
after midnight, then becoming northwest 15 to 25 knots late.
Showers through midnight. A chance of thunderstorms. A chance of
showers after midnight. Waves building to 2 to 4 feet.
.WEDNESDAY...North winds 20 to 30 knots backing northwest by mid
afternoon. A chance of showers. Waves building to 3 to 5 feet
occasionally to 7 feet.
.WEDNESDAY NIGHT...Northwest winds 15 to 25 knots. A chance of
showers. Waves subsiding to 2 to 4 feet.
.THURSDAY...West winds 15 to 25 knots diminishing to 10 to
20 knots by mid afternoon. A chance of showers. Waves subsiding
to 1 to 3 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...Northwest winds 15 to 25 knots. Waves building to 3 to
5 feet occasionally to 7 feet, then subsiding to 2 to 4 feet.
.SATURDAY...Northwest winds 15 to 25 knots diminishing to 5 to
15 knots. Waves subsiding to calm to 2 feet.

$$

LSZ263-020800-
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 Mon Sep 1 2025

.LATE THIS AFTERNOON...Southwest winds 5 to 15 knots. Waves calm
to 2 feet.
.TONIGHT...South winds 5 to 15 knots veering southwest after
midnight. Waves calm to 2 feet.
.TUESDAY...Southwest winds 5 to 15 knots. A chance of showers. A
slight chance of thunderstorms by mid afternoon. Waves building
to 1 to 3 feet, then subsiding to calm to 2 feet.
.TUESDAY NIGHT...Southwest winds 5 to 15 knots becoming west
10 to 20 knots after midnight, then becoming northwest 15 to
25 knots late. Showers and a chance of thunderstorms. Waves
building to 2 to 4 feet.
.WEDNESDAY...North winds 15 to 25 knots backing northwest by mid
afternoon. A chance of showers. Waves building to 3 to 6 feet
occasionally to 8 feet.
.WEDNESDAY NIGHT...Northwest winds 15 to 25 knots. A chance of
showers. Waves subsiding to 3 to 5 feet occasionally to 7 feet.
.THURSDAY...Northwest winds 15 to 25 knots becoming west 10 to
20 knots by mid 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 1 to
3 feet, then building to 2 to 4 feet.
.FRIDAY...Northwest winds 15 to 25 knots. A chance of showers.
Waves building 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 calm to 2 feet.

$$

LSZ264-020800-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
401 PM EDT Mon Sep 1 2025

.LATE THIS AFTERNOON...Southwest winds 5 to 15 knots. Waves calm
to 2 feet.
.TONIGHT...South winds 5 to 15 knots veering southwest late.
Waves calm to 2 feet.
.TUESDAY...Southwest winds 5 to 15 knots. A slight chance of
showers and thunderstorms by mid afternoon. Waves building to
1 to 3 feet, then subsiding to calm to 2 feet.
.TUESDAY NIGHT...South winds 5 to 15 knots veering southwest
after midnight, then becoming northwest 15 to 25 knots late.
Showers and a chance of thunderstorms. Waves building to 2 to
4 feet.
.WEDNESDAY...North winds 15 to 25 knots backing northwest by mid
afternoon. A chance of showers. Waves building to 3 to 6 feet
occasionally to 8 feet.
.WEDNESDAY NIGHT...Northwest winds 15 to 25 knots. A chance of
showers. Waves subsiding to 3 to 5 feet occasionally to 7 feet.
.THURSDAY...Northwest winds 15 to 25 knots becoming west 10 to
20 knots by mid afternoon. A chance of showers. Waves subsiding
to 2 to 4 feet.
.THURSDAY NIGHT...West winds 10 to 20 knots. A chance of showers.
Waves subsiding to 1 to 3 feet.
.FRIDAY...Northwest winds 20 to 30 knots. A chance of showers.
Waves building 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 calm to 2 feet.

$$

LSZ265-020800-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
401 PM EDT Mon Sep 1 2025

.LATE THIS AFTERNOON...Southeast winds 5 to 15 knots. Waves calm
to 2 feet.
.TONIGHT...Southeast winds 5 to 15 knots veering southwest late.
Waves calm to 2 feet.
.TUESDAY...Southwest winds 5 to 15 knots backing southeast in the
afternoon. A slight chance of showers by mid afternoon. Waves
calm to 2 feet.
.TUESDAY NIGHT...South winds 5 to 15 knots becoming southwest
10 to 20 knots after midnight. A chance of showers through
midnight. A chance of thunderstorms. Showers after midnight.
Waves calm to 2 feet.
.WEDNESDAY...Northwest winds 15 to 25 knots increasing to 20 to
30 knots by mid afternoon. Showers likely and a slight chance of
thunderstorms through early afternoon, then a chance of showers
by mid afternoon. Waves building to 3 to 5 feet occasionally to
7 feet.
.WEDNESDAY NIGHT...Northwest winds 20 to 30 knots. A chance of
showers. Waves 3 to 5 feet occasionally to 7 feet.
.THURSDAY...West winds 20 to 30 knots diminishing to 15 to
25 knots by mid afternoon. A chance of showers. Waves subsiding
to 1 to 3 feet.
.THURSDAY NIGHT...West winds 10 to 20 knots backing southwest
after midnight. A chance of showers. Waves subsiding to calm to
2 feet.
.FRIDAY...Northwest winds 15 to 25 knots backing west. A chance
of showers. Waves building to 3 to 5 feet occasionally to 7 feet,
then subsiding to 2 to 4 feet.
.SATURDAY...Northwest winds 15 to 25 knots diminishing to 10 to
20 knots. A chance of showers. Waves subsiding to calm to 2 feet.

$$

LSZ266-020800-
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 Mon Sep 1 2025

.LATE THIS AFTERNOON...Southeast winds 5 to 15 knots. Waves calm
to 2 feet.
.TONIGHT...South winds 5 to 15 knots increasing to 10 to 20 knots
after midnight, then becoming southwest 5 to 15 knots late. Waves
calm to 2 feet.
.TUESDAY...Southwest winds 5 to 15 knots backing south in the
afternoon. A slight chance of showers by mid afternoon. Waves
calm to 2 feet.
.TUESDAY NIGHT...South winds 10 to 20 knots. A slight chance of
showers through midnight. A chance of thunderstorms. Showers
likely after midnight. Waves building to 2 to 4 feet.
.WEDNESDAY...Northwest winds 15 to 25 knots increasing to 20 to
30 knots by mid afternoon. Showers likely through early
afternoon. A slight chance of thunderstorms. A chance of showers
by mid afternoon. Waves building to 3 to 6 feet occasionally to
8 feet.
.WEDNESDAY NIGHT...Northwest winds 20 to 30 knots. A chance of
showers. Waves 3 to 6 feet occasionally to 8 feet.
.THURSDAY...West winds 20 to 30 knots diminishing to 15 to
25 knots by mid afternoon. A chance of showers. Waves 3 to 6 feet
occasionally to 8 feet.
.THURSDAY NIGHT...West winds 15 to 25 knots becoming southwest
10 to 20 knots after midnight. A chance of showers. Waves
subsiding to 2 to 4 feet.
.FRIDAY...West winds 15 to 25 knots becoming northwest 20 to
30 knots. A chance of showers. Waves building to 4 to 7 feet
occasionally to 9 feet.
.SATURDAY...Northwest winds 15 to 25 knots diminishing to 10 to
20 knots. A chance of showers. Waves subsiding to 2 to 4 feet.

$$

LSZ267-020800-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
401 PM EDT Mon Sep 1 2025

.LATE THIS AFTERNOON...Southeast winds 5 to 15 knots. Waves calm
to 2 feet.
.TONIGHT...South winds 5 to 15 knots increasing to 10 to 20 knots
after midnight. Waves calm to 2 feet.
.TUESDAY...South winds 10 to 20 knots becoming southwest 5 to
15 knots in the afternoon, then backing southeast late. Waves
calm to 2 feet.
.TUESDAY NIGHT...South winds 10 to 20 knots increasing to 15 to
25 knots after midnight. A chance of showers and a slight chance
of thunderstorms after midnight. Waves building to 2 to 4 feet,
then subsiding to 1 to 3 feet.
.WEDNESDAY...South winds 15 to 25 knots becoming west 20 to
30 knots by mid afternoon. Showers and a chance of thunderstorms.
Waves building to 3 to 6 feet occasionally to 8 feet.
.WEDNESDAY NIGHT...Northwest winds 15 to 25 knots backing west
after midnight. A chance of showers. Waves subsiding to 3 to
5 feet occasionally to 7 feet.
.THURSDAY...West winds 15 to 25 knots increasing to 20 to
30 knots by mid afternoon. A chance of showers. Waves building to
3 to 6 feet occasionally to 8 feet.
.THURSDAY NIGHT...Southwest winds 15 to 25 knots diminishing to
10 to 20 knots after midnight. A chance of showers. Waves
subsiding to 2 to 4 feet.
.FRIDAY...West winds 15 to 25 knots increasing to 20 to 30 knots.
Showers likely, then a chance of showers. Waves building to 4 to
8 feet occasionally to 10 feet.
.SATURDAY...Northwest winds 15 to 25 knots. A chance of showers.
Waves subsiding to 2 to 4 feet.

$$

LSZ261-020200-
MAFOR 0121/
Superior West 11500 12400 14510 11510. A chance of showers
Tuesday afternoon. Waves 2 feet or less.

Superior North Central 11510 11410 11400 11500 14510. Waves 1 to
3 feet.

Superior South Central 12300 11410 11510 12500 11400 11310. Waves
2 feet or less.

Superior East 11300 11400 13410 11510 11500 11400. Waves 2 feet
or less.

$$

WFO MQT

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