284
FZUS63 KMQT 301401
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1001 AM EDT Tue Sep 30 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 30.5 inch high pressure over James Bay shifts southeast over
Quebec to New England through Thursday. This extends 30.1 to 30.3
inch ridging over Lake Superior during this timeframe. Ridging over
Lake Superior weakens to 30.0 inches by Friday morning as the high
settles south. A 29.9 inch shortwave low then moves across the
western end of Lake Superior Friday night into Saturday. This is
quickly followed up by another low pressure system lifting northeast
over the Midwest late in the day Saturday, continuing to extend
troughing over Lake Superior the remainder of the weekend.


LSZ162-302000-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1001 AM EDT Tue Sep 30 2025 /901 AM CDT Tue Sep 30 2025/

.REST OF TODAY...Northeast winds 15 to 25 knots. Waves 3 to
6 feet occasionally to 8 feet building to 4 to 7 feet
occasionally to 9 feet.
.TONIGHT...Northeast winds 10 to 20 knots becoming east 5 to
15 knots late. Waves subsiding to 1 to 3 feet.
.WEDNESDAY...East winds 5 to 15 knots increasing to 10 to
20 knots in the afternoon. Waves subsiding to calm to 2 feet.
.WEDNESDAY NIGHT...South winds 5 to 15 knots. Waves building to
1 to 3 feet.
.THURSDAY...South winds 5 to 15 knots. Waves subsiding to calm to
2 feet.
.THURSDAY NIGHT...South winds 5 to 15 knots veering southwest
after midnight. Waves calm to 2 feet.
.FRIDAY...Southwest winds 10 to 20 knots. A chance of
thunderstorms. Showers likely. Waves calm to 2 feet.
.SATURDAY...Southwest winds 10 to 20 knots backing east. A chance
of showers. Waves calm to 2 feet.

$$

LSZ263-302000-
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 Tue Sep 30 2025

.REST OF TODAY...East winds 15 to 25 knots. Waves 3 to 6 feet
occasionally to 8 feet.
.TONIGHT...East winds 10 to 20 knots veering southeast after
midnight, then diminishing to 5 to 15 knots late. Waves subsiding
to 2 to 4 feet.
.WEDNESDAY...Southeast winds 5 to 15 knots becoming east 10 to
20 knots late. Waves 2 to 4 feet.
.WEDNESDAY NIGHT...South winds 10 to 20 knots. Waves subsiding to
1 to 3 feet.
.THURSDAY...South winds 10 to 20 knots. Waves subsiding to calm
to 2 feet.
.THURSDAY NIGHT...South winds 10 to 20 knots veering southwest
after midnight. Waves building to 1 to 3 feet.
.FRIDAY...Southwest winds 10 to 20 knots diminishing to 5 to
15 knots. A chance of thunderstorms. Showers likely. Waves
subsiding to calm to 2 feet.
.SATURDAY...Southwest winds 5 to 15 knots backing southeast. A
chance of showers. Waves calm to 2 feet.

$$

LSZ264-302000-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
1001 AM EDT Tue Sep 30 2025

.REST OF TODAY...East winds 15 to 25 knots. Waves 3 to 6 feet
occasionally to 8 feet.
.TONIGHT...East winds 10 to 20 knots veering southeast after
midnight. Waves 3 to 5 feet occasionally to 7 feet.
.WEDNESDAY...Southeast winds 15 to 25 knots. Waves building to
3 to 6 feet occasionally to 8 feet.
.WEDNESDAY NIGHT...South winds 15 to 25 knots diminishing to
10 to 20 knots after midnight. Waves subsiding to 2 to 4 feet.
.THURSDAY...South winds 10 to 20 knots. Waves 2 to 4 feet.
.THURSDAY NIGHT...South winds 10 to 20 knots veering southwest
after midnight. Waves subsiding to 1 to 3 feet.
.FRIDAY...Southwest winds 10 to 20 knots diminishing to 5 to
15 knots. Showers likely and a chance of thunderstorms. Waves
subsiding to calm to 2 feet.
.SATURDAY...Southwest winds 5 to 15 knots backing south. A chance
of showers. Waves calm to 2 feet.

$$

LSZ265-302000-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1001 AM EDT Tue Sep 30 2025

.REST OF TODAY...East winds 10 to 20 knots increasing to 15 to
25 knots in the afternoon. Waves 3 to 5 feet occasionally to
7 feet.
.TONIGHT...East winds 10 to 20 knots veering southeast after
midnight. Waves subsiding to 2 to 4 feet.
.WEDNESDAY...Southeast winds 15 to 25 knots. Waves 2 to 4 feet.
.WEDNESDAY NIGHT...South winds 15 to 25 knots. Waves subsiding to
calm to 2 feet.
.THURSDAY...South winds 15 to 25 knots. Waves calm to 2 feet.
.THURSDAY NIGHT...South winds 15 to 25 knots becoming southwest
10 to 20 knots after midnight. Waves calm to 2 feet.
.FRIDAY...South winds 10 to 20 knots veering southwest. A chance
of showers. Waves calm to 2 feet.
.SATURDAY...Southwest winds 10 to 20 knots backing south. A
chance of showers. Waves calm to 2 feet.

$$

LSZ266-302000-
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 Tue Sep 30 2025

.REST OF TODAY...East winds 10 to 20 knots. Waves 3 to 6 feet
occasionally to 8 feet.
.TONIGHT...East winds 10 to 20 knots veering southeast after
midnight. Waves subsiding to 2 to 4 feet.
.WEDNESDAY...Southeast winds 10 to 20 knots increasing to 15 to
25 knots in the afternoon. Waves building to 3 to 6 feet
occasionally to 8 feet.
.WEDNESDAY NIGHT...South winds 15 to 25 knots. Waves subsiding to
2 to 4 feet.
.THURSDAY...South winds 15 to 25 knots. Waves building to 3 to
5 feet occasionally to 7 feet, then subsiding to 2 to 4 feet.
.THURSDAY NIGHT...South winds 15 to 25 knots. Waves subsiding to
2 to 4 feet.
.FRIDAY...South winds 10 to 20 knots. A chance of showers. Waves
subsiding to 1 to 3 feet.
.SATURDAY...Southwest winds 10 to 20 knots backing south. A
chance of showers. Waves subsiding to calm to 2 feet.

$$

LSZ267-302000-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1001 AM EDT Tue Sep 30 2025

.REST OF TODAY...East winds 10 to 20 knots. Waves 2 to 4 feet
subsiding to calm to 2 feet.
.TONIGHT...East winds 10 to 20 knots veering southeast after
midnight. Waves building to 2 to 4 feet.
.WEDNESDAY...Southeast winds 10 to 20 knots. Waves subsiding to
1 to 3 feet.
.WEDNESDAY NIGHT...Southeast winds 15 to 25 knots veering south
after midnight. Waves building to 2 to 4 feet.
.THURSDAY...South winds 15 to 25 knots. Waves 2 to 4 feet.
.THURSDAY NIGHT...South winds 15 to 25 knots. Waves 2 to 4 feet.
.FRIDAY...South winds 15 to 25 knots. A chance of showers. A
chance of thunderstorms. Waves subsiding to 1 to 3 feet.
.SATURDAY...South winds 10 to 20 knots. A chance of showers.
Waves subsiding to calm to 2 feet.

$$

LSZ261-302000-
MAFOR 3015/
Superior West 14130 11220 12210 11310. Waves 4 to 6 feet this
afternoon. Waves 4 to 7 feet subsiding to 3 to 6 feet tonight.
Waves 2 to 4 feet Wednesday morning.

Superior North Central 14230 12320 12330. Waves 3 to 6 feet.

Superior South Central 13230 11220 13320 11330. Waves 3 to 5 feet
this afternoon. Waves 3 to 5 feet subsiding to 2 to 3 feet
tonight. Waves 2 to 4 feet Wednesday morning.

Superior East 11230 14220 13320. Waves 2 to 4 feet this
afternoon. Waves 1 to 3 feet building to 2 to 4 feet tonight.
Waves 2 to 4 feet Wednesday 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