478
FZUS63 KMQT 040801
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
401 AM EDT Sat Oct 4 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 29.6 inch low over the Dakotas will lift towards Lake Winnipeg by
late morning, then later in the day a 29.4 inch low develops off of
the Colorado Rockies. This second low lifts northeast on Sunday to
northwestern Ontario, quickly reaching far northern Quebec by Monday
morning as it deepens to at least 29.2 inches. This results in at
least 29.8 inch troughing over Lake Superior more towards sunrise
today, which holds until Monday morning. In its wake, a 30.3 inch
high pressure moving across the Northern Plains brings ridging of
30.1 inches back over Lake Superior by Monday. A reinforcing 30.3
inch high pressure dropping down from the Canadian Prairies into the
Northern Plains on Tuesday brings 30.2 inch ridging to Lake Superior
by Tuesday evening. The high then strengthens to around 30.4 inches
close to the lake Tuesday night into Wednesday. This becomes
centered over New England by Thursday afternoon as low pressure
moves towards Hudson Bay, bringing 29.8 inch  troughing to the lake
by Thursday night.


LSZ162-042000-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
401 AM EDT Sat Oct 4 2025 /301 AM CDT Sat Oct 4 2025/

...GALE WATCH IN EFFECT FROM SUNDAY AFTERNOON THROUGH LATE SUNDAY
NIGHT...

.EARLY THIS MORNING...East winds 5 to 15 knots. Patchy dense fog.
Waves calm to 2 feet.
.TODAY...South winds 10 to 20 knots backing east in the
afternoon, then becoming south 15 to 25 knots late. Patchy dense
fog through early afternoon. Waves building to 1 to 3 feet.
.TONIGHT...South winds 15 to 25 knots increasing to 20 to
30 knots late. Waves building to 3 to 5 feet occasionally to
7 feet.
.SUNDAY...South winds 20 to 30 knots increasing to gales to
35 knots in the afternoon, then veering southwest late. A slight
chance of showers and thunderstorms by mid afternoon. Waves
building to 5 to 8 feet occasionally to 10 feet.
.SUNDAY NIGHT...West gales to 35 knots becoming northwest 15 to
25 knots after midnight. A slight chance of showers and
thunderstorms through midnight. Waves subsiding to 1 to 3 feet.
.MONDAY...Northwest winds 10 to 20 knots backing southwest by mid
afternoon. Waves subsiding to calm to 2 feet.
.MONDAY NIGHT...West winds 10 to 20 knots increasing to 15 to
25 knots after midnight. Waves building to 2 to 4 feet.
.TUESDAY...West winds 10 to 20 knots becoming north 5 to
15 knots. Waves subsiding to calm to 2 feet.
.WEDNESDAY...South winds 5 to 15 knots increasing to 10 to
20 knots. Waves building to 2 to 4 feet.

$$

LSZ263-042000-
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 AM EDT Sat Oct 4 2025

...GALE WATCH IN EFFECT FROM SUNDAY AFTERNOON THROUGH LATE SUNDAY
NIGHT...

.EARLY THIS MORNING...South winds 10 to 20 knots. Patchy dense
fog. Waves calm to 2 feet.
.TODAY...South winds 10 to 20 knots increasing to 15 to 25 knots
in the afternoon. Patchy dense fog through early afternoon. Waves
building to 2 to 4 feet, then subsiding to 1 to 3 feet.
.TONIGHT...South winds 15 to 25 knots increasing to 20 to
30 knots late. Waves building to 3 to 6 feet occasionally to
8 feet.
.SUNDAY...South winds 20 to 30 knots increasing to gales to
40 knots in the afternoon. A slight chance of showers and
thunderstorms by mid afternoon. Waves building to 5 to 8 feet
occasionally to 10 feet.
.SUNDAY NIGHT...Southwest gales to 40 knots becoming west 20 to
30 knots after midnight. A chance of showers and a slight chance
of thunderstorms through midnight. Waves subsiding to 3 to 5 feet
occasionally to 7 feet.
.MONDAY...Northwest winds 10 to 20 knots backing west by mid
afternoon. Waves subsiding to calm to 2 feet, then building to
1 to 3 feet.
.MONDAY NIGHT...West winds 10 to 20 knots increasing to 15 to
25 knots after midnight. Waves building to 3 to 5 feet
occasionally to 7 feet.
.TUESDAY...West winds 15 to 25 knots becoming north 5 to
15 knots. Waves building to 3 to 6 feet occasionally to 8 feet,
then subsiding to calm to 2 feet.
.WEDNESDAY...Southwest winds 5 to 15 knots becoming south 15 to
25 knots. Waves building to 2 to 4 feet.

$$

LSZ264-042000-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
401 AM EDT Sat Oct 4 2025

...GALE WATCH IN EFFECT FROM SUNDAY AFTERNOON THROUGH LATE SUNDAY
NIGHT...

.EARLY THIS MORNING...South winds 10 to 20 knots. Patchy dense
fog. Waves 1 to 3 feet.
.TODAY...South winds 10 to 20 knots increasing to 15 to 25 knots
in the afternoon. Patchy dense fog through early afternoon. Waves
building to 2 to 4 feet.
.TONIGHT...South winds 15 to 25 knots increasing to 20 to
30 knots late. Waves building to 3 to 6 feet occasionally to
8 feet.
.SUNDAY...South winds 20 to 30 knots increasing to gales to
35 knots late. A slight chance of showers by mid afternoon. Waves
building to 5 to 8 feet occasionally to 10 feet.
.SUNDAY NIGHT...Southwest gales to 35 knots becoming west 20 to
30 knots after midnight. A chance of showers and a slight chance
of thunderstorms through midnight. Waves subsiding to 4 to 7 feet
occasionally to 9 feet.
.MONDAY...Northwest winds 10 to 20 knots backing west by mid
afternoon. Waves subsiding to calm to 2 feet.
.MONDAY NIGHT...West winds 10 to 20 knots increasing to 15 to
25 knots after midnight. Waves building to 3 to 5 feet
occasionally to 7 feet.
.TUESDAY...Northwest winds 20 to 30 knots becoming north 5 to
15 knots. Waves building to 3 to 6 feet occasionally to 8 feet,
then subsiding to calm to 2 feet.
.WEDNESDAY...West winds 5 to 15 knots becoming south 15 to
25 knots. Waves building to 2 to 4 feet.

$$

LSZ265-042000-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
401 AM EDT Sat Oct 4 2025

...GALE WATCH IN EFFECT FROM SUNDAY AFTERNOON THROUGH LATE SUNDAY
NIGHT...

.EARLY THIS MORNING...South winds 10 to 20 knots. Patchy fog.
Waves calm to 2 feet.
.TODAY...South winds 15 to 25 knots. Waves building to 1 to
3 feet.
.TONIGHT...South winds 20 to 30 knots diminishing to 15 to
25 knots after midnight. Waves building to 2 to 4 feet, then
subsiding to 1 to 3 feet.
.SUNDAY...South winds 20 to 30 knots increasing to gales to
35 knots in the afternoon. Waves building to 3 to 5 feet
occasionally to 7 feet.
.SUNDAY NIGHT...South gales to 35 knots becoming west 20 to
30 knots after midnight. A slight chance of thunderstorms through
midnight. A chance of showers. Waves subsiding to 2 to 4 feet.
.MONDAY...Northwest winds 15 to 25 knots diminishing to 10 to
20 knots by mid afternoon. Waves subsiding to calm to 2 feet.
.MONDAY NIGHT...West winds 10 to 20 knots increasing to 15 to
25 knots after midnight. Waves calm to 2 feet.
.TUESDAY...Northwest winds 15 to 25 knots diminishing to 10 to
20 knots. Waves building to 2 to 4 feet, then subsiding to calm
to 2 feet.
.WEDNESDAY...Northwest winds 10 to 20 knots backing south. Waves
calm to 2 feet.

$$

LSZ266-042000-
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 AM EDT Sat Oct 4 2025

...GALE WATCH IN EFFECT FROM SUNDAY AFTERNOON THROUGH LATE SUNDAY
NIGHT...

.EARLY THIS MORNING...South winds 10 to 20 knots. Patchy fog.
Waves 1 to 3 feet.
.TODAY...South winds 15 to 25 knots increasing to 20 to 30 knots
late. Patchy fog through early afternoon. Waves building to 3 to
5 feet occasionally to 7 feet.
.TONIGHT...South winds 20 to 30 knots diminishing to 15 to
25 knots after midnight. Waves building to 3 to 6 feet
occasionally to 8 feet.
.SUNDAY...South winds 20 to 30 knots increasing to gales to
35 knots late. Waves building to 6 to 9 feet occasionally to
11 feet.
.SUNDAY NIGHT...South gales to 40 knots becoming west 20 to
30 knots after midnight. A chance of showers and a slight chance
of thunderstorms. Waves building to 7 to 10 feet occasionally to
13 feet, then subsiding to 4 to 7 feet occasionally to 9 feet.
.MONDAY...Northwest winds 15 to 25 knots diminishing to 10 to
20 knots by mid afternoon. Waves subsiding to 2 to 4 feet.
.MONDAY NIGHT...West winds 5 to 15 knots increasing to 15 to
25 knots after midnight. Waves subsiding to 1 to 3 feet, then
building to 3 to 5 feet occasionally to 7 feet.
.TUESDAY...Northwest winds 15 to 25 knots becoming north 10 to
20 knots. Waves building to 4 to 7 feet occasionally to 9 feet,
then subsiding to 1 to 3 feet.
.WEDNESDAY...Northwest winds 10 to 20 knots backing south. Waves
subsiding to calm to 2 feet, then building to 2 to 4 feet.

$$

LSZ267-042000-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
401 AM EDT Sat Oct 4 2025

.EARLY THIS MORNING...Southeast winds 10 to 20 knots. Waves calm
to 2 feet.
.TODAY...South winds 10 to 20 knots increasing to 15 to 25 knots
in the afternoon. Waves building to 2 to 4 feet.
.TONIGHT...South winds 20 to 30 knots diminishing to 15 to
25 knots after midnight. Waves building to 3 to 5 feet
occasionally to 7 feet, then subsiding to 2 to 4 feet.
.SUNDAY...South winds 15 to 25 knots increasing to 30 knots with
a few gale force gusts to 35 knots possible. Waves building to
5 to 8 feet occasionally to 10 feet.
.SUNDAY NIGHT...South gales to 35 knots becoming west 20 to
30 knots after midnight. A chance of showers through midnight. A
slight chance of thunderstorms. Showers after midnight. Waves
subsiding to 3 to 6 feet occasionally to 8 feet.
.MONDAY...Northwest winds 15 to 25 knots diminishing to 10 to
20 knots by mid afternoon. A chance of showers through early
afternoon. Waves subsiding to 2 to 4 feet.
.MONDAY NIGHT...West winds 10 to 20 knots. A chance of showers.
Waves subsiding to calm to 2 feet, then building to 1 to 3 feet.
.TUESDAY...West winds 15 to 25 knots becoming north 10 to
20 knots. Waves building to 4 to 7 feet occasionally to 9 feet,
then subsiding to 1 to 3 feet.
.WEDNESDAY...Northwest winds 10 to 20 knots backing south. Waves
subsiding to calm to 2 feet, then building to 1 to 3 feet.

$$

LSZ261-041400-
MAFOR 0409/
Superior West 11410 12420 19424 11320 13430 11440. Waves 1 to 3
feet today. Waves 2 to 4 feet tonight.

Superior North Central 11420 19424 13420 13430 11440. Waves 1 to
3 feet building to 2 to 4 feet today. Waves 2 to 4 feet building
to 3 to 5 feet tonight.

Superior South Central 11410 13420 13430 11420. Waves 1 to 3 feet
building to 2 to 4 feet today. Waves 2 to 4 feet tonight.

Superior East 11310 13420 14440. Waves 1 to 3 feet building to 2
to 4 feet today. Waves 3 to 6 feet tonight.

$$

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