700
FZUS63 KMQT 150801
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
401 AM EDT Wed Oct 15 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...

30.4 inch high pressure over Lake Superior today gradually weakens
to 30.1 inches as it shifts eastward across the Great Lakes through
Thursday evening. A deepening 29.3 inch low develops over the
Northern Plains Thursday night and and lifts near Lake Winnipeg at
29.2 inches Friday morning. This will send 29.5 inch troughing over
Lake Superior Friday into Saturday as the low moves to Hudson Bay. A
secondary low deepens to 29.3 inches near the Straits of Mackinac
Sunday morning and moves over James Bay by Sunday night. 29.8 inch
ridging returns to Lake Superior on Monday.


LSZ162-152000-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
401 AM EDT Wed Oct 15 2025 /301 AM CDT Wed Oct 15 2025/

.EARLY THIS MORNING...East winds 5 to 15 knots. Waves calm to
2 feet.
.TODAY...East winds 5 to 15 knots. Waves calm to 2 feet.
.TONIGHT...East winds 5 to 15 knots veering southeast late. A
slight chance of rain after midnight. Waves calm to 2 feet.
.THURSDAY...Southeast winds 10 to 20 knots. A chance of rain
through early afternoon, then rain by mid afternoon. Waves calm
to 2 feet.
.THURSDAY NIGHT...Southeast winds 10 to 20 knots veering south
after midnight. Rain likely through midnight, then a chance of
rain after midnight. Waves building to 1 to 3 feet, then
subsiding to calm to 2 feet.
.FRIDAY...South winds 15 to 25 knots. A chance of showers. Waves
building to 3 to 5 feet occasionally to 7 feet, then subsiding to
2 to 4 feet.
.FRIDAY NIGHT...Southwest winds 15 to 25 knots diminishing to
10 to 20 knots after midnight. A chance of showers. Waves
subsiding to 1 to 3 feet.
.SATURDAY...West winds 10 to 20 knots increasing to 15 to
25 knots. Waves building to 2 to 4 feet, then subsiding to 1 to
3 feet.
.SUNDAY...West winds 15 to 25 knots diminishing to 10 to
20 knots. Waves subsiding to calm to 2 feet.

$$

LSZ263-152000-
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 Wed Oct 15 2025

.EARLY THIS MORNING...West winds less than 10 knots. Waves calm
to 2 feet.
.TODAY...West winds less than 10 knots becoming southwest 5 to
15 knots late. Waves calm to 2 feet.
.TONIGHT...Southwest winds less than 10 knots becoming southeast
5 to 15 knots after midnight, then veering south late. Waves calm
to 2 feet.
.THURSDAY...Southeast winds 5 to 15 knots increasing to 10 to
20 knots in the afternoon. A slight chance of rain through early
afternoon, then rain likely by mid afternoon. Waves calm to
2 feet.
.THURSDAY NIGHT...South winds 10 to 20 knots increasing to 15 to
25 knots after midnight. Rain through midnight, then a chance of
rain after midnight. Waves building to 2 to 4 feet.
.FRIDAY...South winds 20 to 30 knots diminishing to 15 to
25 knots by mid afternoon. A chance of showers. Waves building to
3 to 5 feet occasionally to 7 feet.
.FRIDAY NIGHT...Southwest winds 15 to 25 knots. A chance of
showers. Waves subsiding to 2 to 4 feet.
.SATURDAY...Southwest winds 20 to 30 knots veering west. Waves
building to 3 to 5 feet occasionally to 7 feet, then subsiding to
2 to 4 feet.
.SUNDAY...West gales to 35 knots diminishing to 15 to 25 knots.
Waves building to 4 to 7 feet occasionally to 9 feet, then
subsiding to 1 to 3 feet.

$$

LSZ264-152000-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
401 AM EDT Wed Oct 15 2025

.EARLY THIS MORNING...North winds less than 10 knots. Waves calm
to 2 feet.
.TODAY...West winds less than 10 knots increasing to 5 to
15 knots in the afternoon, then diminishing to less than 10 knots
late. Waves calm to 2 feet.
.TONIGHT...West winds less than 10 knots backing southwest after
midnight, then becoming south 5 to 15 knots late. Waves calm to
2 feet.
.THURSDAY...South winds 5 to 15 knots increasing to 10 to
20 knots in the afternoon, then backing southeast late. A chance
of rain by mid afternoon. Waves building to 1 to 3 feet.
.THURSDAY NIGHT...South winds 15 to 25 knots. Rain. Waves
building to 3 to 6 feet occasionally to 8 feet.
.FRIDAY...South winds 15 to 25 knots. A chance of showers. Waves
3 to 6 feet occasionally to 8 feet.
.FRIDAY NIGHT...South winds 15 to 25 knots veering southwest
after midnight. Showers likely through midnight, then a chance of
showers after midnight. Waves subsiding to 3 to 5 feet
occasionally to 7 feet.
.SATURDAY...Southwest winds 20 to 30 knots veering west. A chance
of showers. Waves subsiding to 2 to 4 feet, then building to 3 to
6 feet occasionally to 8 feet.
.SUNDAY...West gales to 35 knots diminishing to 15 to 25 knots. A
chance of showers. Waves building to 4 to 7 feet occasionally to
9 feet, then subsiding to 2 to 4 feet.

$$

LSZ265-152000-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
401 AM EDT Wed Oct 15 2025

.EARLY THIS MORNING...North winds 5 to 15 knots. Waves calm to
2 feet.
.TODAY...North winds 5 to 15 knots backing northwest in the
afternoon, then veering north late. Waves calm to 2 feet.
.TONIGHT...West winds less than 10 knots becoming south 5 to
15 knots after midnight. Waves calm to 2 feet.
.THURSDAY...South winds 5 to 15 knots becoming southeast 10 to
20 knots in the afternoon, then increasing to 15 to 25 knots
late. A chance of rain by mid afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...South winds 15 to 25 knots. Rain. Waves
building to 1 to 3 feet.
.FRIDAY...South winds 20 to 30 knots. A chance of showers. Waves
building to 2 to 4 feet.
.FRIDAY NIGHT...South winds 20 to 30 knots diminishing to 15 to
25 knots after midnight. Showers likely. Waves subsiding to calm
to 2 feet.
.SATURDAY...West winds 10 to 20 knots increasing to 15 to
25 knots. A chance of showers. Waves calm to 2 feet.
.SUNDAY...West winds 20 to 30 knots diminishing to 15 to
25 knots. A chance of showers. Waves building to 2 to 4 feet,
then subsiding to calm to 2 feet.

$$

LSZ266-152000-
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 Wed Oct 15 2025

.EARLY THIS MORNING...North winds 5 to 15 knots. Waves calm to
2 feet.
.TODAY...North winds 5 to 15 knots backing northwest in the
afternoon. Waves calm to 2 feet.
.TONIGHT...Northwest winds less than 10 knots increasing to 5 to
15 knots after midnight, then backing south late. Waves calm to
2 feet.
.THURSDAY...South winds 5 to 15 knots increasing to 10 to
20 knots in the afternoon, then becoming southeast 15 to 25 knots
late. A chance of rain by mid afternoon. Waves building to 1 to
3 feet.
.THURSDAY NIGHT...South winds 15 to 25 knots increasing to 20 to
30 knots after midnight. Rain. Waves building to 4 to 7 feet
occasionally to 9 feet.
.FRIDAY...South gales to 35 knots. A chance of showers. Waves
building to 5 to 8 feet occasionally to 10 feet.
.FRIDAY NIGHT...South gales to 35 knots diminishing to 20 to
30 knots after midnight. Showers. Waves building to 6 to 9 feet
occasionally to 11 feet, then subsiding to 3 to 6 feet
occasionally to 8 feet.
.SATURDAY...West winds 15 to 25 knots. Showers likely, then a
chance of showers. Waves subsiding to 2 to 4 feet, then building
to 3 to 5 feet occasionally to 7 feet.
.SUNDAY...West winds 20 to 30 knots. A chance of showers. Waves
building to 4 to 7 feet occasionally to 9 feet, then subsiding to
3 to 5 feet occasionally to 7 feet.

$$

LSZ267-152000-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
401 AM EDT Wed Oct 15 2025

.EARLY THIS MORNING...Northeast winds 5 to 15 knots. Waves calm
to 2 feet.
.TODAY...Northeast winds 5 to 15 knots backing northwest in the
afternoon. Waves calm to 2 feet.
.TONIGHT...Northwest winds 5 to 15 knots veering north late.
Waves calm to 2 feet.
.THURSDAY...East winds 5 to 15 knots veering southeast in the
afternoon. A slight chance of rain by mid afternoon. Waves calm
to 2 feet.
.THURSDAY NIGHT...South winds 10 to 20 knots increasing to 20 to
30 knots after midnight. Rain. Waves building to 3 to 5 feet
occasionally to 7 feet.
.FRIDAY...South winds 20 to 30 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 5 to 8 feet occasionally to 10 feet.
.FRIDAY NIGHT...South gales to 35 knots diminishing to 20 to
30 knots after midnight. Showers. Waves subsiding to 3 to 6 feet
occasionally to 8 feet.
.SATURDAY...South winds 15 to 25 knots becoming west 10 to
20 knots. Showers. Waves subsiding to calm to 2 feet, then
building to 1 to 3 feet.
.SUNDAY...Northwest winds 15 to 25 knots backing west. Showers
likely, then a chance of showers. Waves building to 5 to 8 feet
occasionally to 10 feet, then subsiding to 3 to 6 feet
occasionally to 8 feet.

$$

LSZ261-151400-
MAFOR 1509/
Superior West 11500 14300 11200 12300. Waves 1 foot or less.

Superior North Central 11800 14600 11600 12500. Waves 1 foot or
less.

Superior South Central 12800 12700 11800 11700 11500 11400. Waves
2 feet or less.

Superior East 11100 11800 15700. Waves 2 feet or less.

$$

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