449
FZUS63 KMQT 041401
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1001 AM EDT Fri Jul 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...

30.0 inch ridging builds to 30.1 inches this morning as it shifts
over southern Ontario and the Lower Great Lakes while a 29.4 inch
low over northern Saskatchewan drapes a trough of 29.7 inches over
the Northern Great Plains. By Saturday, the ridge will shift over
the East Coast and the low moves over Hudson Bay, pressing troughing
of 29.7 inches over Lake Superior. The trough then lingers over the
lake through Sunday morning, with 30.1 inch high pressure building
over the Plains. This high moves over the Great Lakes basin late
Sunday, then migrates eastward Monday. Tuesday, another high builds
across Hudson Bay which will sustain 30.0 or 30.1 inch ridging
through at least early Thursday.


LSZ162-042000-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1001 AM EDT Fri Jul 4 2025 /901 AM CDT Fri Jul 4 2025/

.REST OF TODAY...East winds 10 to 20 knots. A slight chance of
showers and thunderstorms by late morning. Waves calm to 2 feet.
.TONIGHT...South winds 10 to 20 knots. A chance of showers and
thunderstorms. Waves calm to 2 feet.
.SATURDAY...Southwest winds 10 to 20 knots veering west late.
Showers and a chance of thunderstorms. Waves calm to 2 feet.
.SATURDAY NIGHT...North winds 10 to 20 knots. A slight chance of
thunderstorms through midnight. A chance of showers. Waves calm
to 2 feet.
.SUNDAY...Northeast winds 10 to 20 knots becoming east 5 to
15 knots by mid afternoon. Waves building to 1 to 3 feet, then
subsiding to calm to 2 feet.
.SUNDAY NIGHT...Northeast winds 5 to 15 knots backing northwest
after midnight. Waves calm to 2 feet.
.MONDAY...South winds 5 to 15 knots backing northeast. A chance
of showers. Waves calm to 2 feet.
.TUESDAY...East winds 5 to 15 knots backing northeast. A chance
of showers. Waves calm to 2 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-
1001 AM EDT Fri Jul 4 2025

.REST OF TODAY...South winds 5 to 15 knots. A chance of showers
and a slight chance of thunderstorms. Waves calm to 2 feet.
.TONIGHT...South winds 10 to 20 knots veering southwest after
midnight. A chance of showers and thunderstorms. Waves building
to 1 to 3 feet.
.SATURDAY...Southwest winds 5 to 15 knots veering west late.
Showers and a chance of thunderstorms. Waves subsiding to calm to
2 feet.
.SATURDAY NIGHT...North winds 5 to 15 knots increasing to 10 to
20 knots after midnight. Showers likely and a slight chance of
thunderstorms through midnight, then a slight chance of showers
after midnight. Waves building to 1 to 3 feet.
.SUNDAY...North winds 10 to 20 knots becoming northeast 5 to
15 knots by mid afternoon. Waves building to 2 to 4 feet, then
subsiding to calm to 2 feet.
.SUNDAY NIGHT...North winds 5 to 15 knots becoming west less than
10 knots after midnight. Waves calm to 2 feet.
.MONDAY...South winds 5 to 15 knots backing southeast. A chance
of showers. Waves calm to 2 feet.
.TUESDAY...East winds 5 to 15 knots backing northeast. A chance
of showers. Waves calm to 2 feet.

$$

LSZ264-042000-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
1001 AM EDT Fri Jul 4 2025

.REST OF TODAY...South winds 5 to 15 knots becoming southeast
10 to 20 knots in the afternoon, then diminishing to 5 to
15 knots late. A slight chance of showers and thunderstorms.
Waves 1 to 3 feet building to 2 to 4 feet, then subsiding to 1 to
3 feet.
.TONIGHT...South winds 5 to 15 knots increasing to 10 to 20 knots
after midnight, then veering southwest late. A slight chance of
showers and thunderstorms. Waves building to 2 to 4 feet, then
subsiding to 1 to 3 feet.
.SATURDAY...Southwest winds 10 to 20 knots diminishing to 5 to
15 knots in the afternoon. Showers and a chance of thunderstorms.
Waves subsiding to calm to 2 feet.
.SATURDAY NIGHT...North winds 5 to 15 knots increasing to 10 to
20 knots after midnight. Showers likely through midnight. A
slight chance of thunderstorms. A chance of showers after
midnight. Waves building to 2 to 4 feet.
.SUNDAY...North winds 10 to 20 knots diminishing to 5 to 15 knots
by mid afternoon. Waves subsiding to calm to 2 feet.
.SUNDAY NIGHT...North winds 5 to 15 knots diminishing to less
than 10 knots after midnight. Waves calm to 2 feet.
.MONDAY...Southwest winds 5 to 15 knots backing south. Waves calm
to 2 feet.
.TUESDAY...Southeast winds 5 to 15 knots backing east. A chance
of showers. Waves calm to 2 feet.

$$

LSZ265-042000-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1001 AM EDT Fri Jul 4 2025

.REST OF TODAY...Southeast winds 10 to 20 knots veering south
late. A slight chance of showers and thunderstorms. Waves 1 to
3 feet.
.TONIGHT...South winds 10 to 20 knots increasing to 15 to
25 knots after midnight, then diminishing to 10 to 20 knots late.
Waves subsiding to calm to 2 feet.
.SATURDAY...Southwest winds 10 to 20 knots backing south in the
afternoon. A chance of showers through early afternoon. A chance
of thunderstorms. Showers by mid afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...West winds 10 to 20 knots becoming northwest
15 to 25 knots after midnight. Showers and a chance of
thunderstorms through midnight, then a chance of showers after
midnight. Waves building to 1 to 3 feet.
.SUNDAY...North winds 15 to 25 knots diminishing to 10 to
20 knots by mid afternoon. Waves building to 2 to 4 feet, then
subsiding to 1 to 3 feet.
.SUNDAY NIGHT...North winds 5 to 15 knots. Waves subsiding to
calm to 2 feet.
.MONDAY...Northeast winds 5 to 15 knots veering southeast. Waves
calm to 2 feet.
.TUESDAY...East winds 10 to 20 knots becoming southeast 5 to
15 knots. A chance of showers. 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-
1001 AM EDT Fri Jul 4 2025

.REST OF TODAY...Southeast winds 10 to 20 knots increasing to
15 to 25 knots in the afternoon, then veering south late. A
slight chance of showers. A slight chance of thunderstorms by mid
afternoon. Waves 1 to 3 feet building to 2 to 4 feet, then
subsiding to 1 to 3 feet.
.TONIGHT...South winds 15 to 25 knots. A slight chance of
thunderstorms through midnight. A slight chance of showers. Waves
2 to 4 feet.
.SATURDAY...South winds 10 to 20 knots. A slight chance of
showers through early afternoon. A chance of thunderstorms.
Showers likely by mid afternoon. Waves subsiding to calm to
2 feet.
.SATURDAY NIGHT...Southwest winds 10 to 20 knots becoming north
15 to 25 knots after midnight. Showers through midnight. A chance
of thunderstorms. A chance of showers after midnight. Waves
building to 2 to 4 feet.
.SUNDAY...North winds 15 to 25 knots diminishing to 10 to
20 knots by mid afternoon. A slight chance of showers through
early afternoon. Waves 2 to 4 feet.
.SUNDAY NIGHT...North winds 5 to 15 knots. Waves subsiding to
calm to 2 feet.
.MONDAY...North winds 5 to 15 knots veering south. Waves calm to
2 feet.
.TUESDAY...Southeast winds 5 to 15 knots. A chance of showers.
Waves calm to 2 feet.

$$

LSZ267-042000-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1001 AM EDT Fri Jul 4 2025

.REST OF TODAY...Southeast winds 10 to 20 knots veering south
late. Waves calm to 2 feet building to 1 to 3 feet.
.TONIGHT...South winds 15 to 25 knots. A slight chance of showers
and thunderstorms. Waves building to 2 to 4 feet, then subsiding
to 1 to 3 feet.
.SATURDAY...South winds 10 to 20 knots. A chance of showers. A
chance of thunderstorms by mid afternoon. Waves subsiding to calm
to 2 feet.
.SATURDAY NIGHT...Southwest winds 10 to 20 knots veering west
after midnight. Showers and a chance of thunderstorms. Waves
building to 1 to 3 feet.
.SUNDAY...North winds 15 to 25 knots. A chance of showers and a
slight chance of thunderstorms through early afternoon. Waves
building to 2 to 4 feet.
.SUNDAY NIGHT...North winds 10 to 20 knots. Waves subsiding to
calm to 2 feet.
.MONDAY...North winds 10 to 20 knots becoming northwest 5 to
15 knots. Waves calm to 2 feet.
.TUESDAY...North winds 5 to 15 knots becoming east 10 to
20 knots. A chance of showers. Waves calm to 2 feet.

$$

LSZ261-042000-
MAFOR 0415/
Superior West 13310 11410 11520 11420 11410 11516. A chance of
thunderstorms overnight and Saturday morning. Waves 2 feet or
less.

Superior North Central 13320 12420 11520 11510 11516. A chance of
thunderstorms Saturday morning. Waves 1 to 3 feet building to 2
to 4 feet this afternoon and tonight. Waves 1 to 3 feet Saturday
morning.

Superior South Central 12320 14420 12410. Waves 2 to 3 feet this
afternoon. Waves 2 to 4 feet subsiding to 1 to 3 feet tonight.
Waves 1 to 2 feet Saturday morning.

Superior East 11310 11320 15420. Waves 2 to 4 feet.

$$

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