658
FZUS63 KMQT 170803
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
401 AM EDT Tue Jun 17 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 currently over the northern lake moves into
northeastern Ontario this afternoon before deepening to 29.4 inches,
and to 29.2 inches over northern Quebec Wednesday morning.
Meanwhile, a weak 29.8 inch ridge builds over the lake this
afternoon into early Wednesday. By late Wednesday, a 29.6 inch low
approaches Lake Michigan from the southwest while another 29.7 inch
trough approaches Lake Superior from the northwest. These two
features merge into a 29.5 inch low over Georgian Bay Wednesday
night while a 30.0 inch high moves over northern Ontario. Weak 30.0
inch ridging then remains over Lake Superior until Friday. On
Saturday, a shortwave around 29.6 inches is expected to move through
the lake.


LSZ162-172000-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
402 AM EDT Tue Jun 17 2025 /302 AM CDT Tue Jun 17 2025/

...DENSE FOG ADVISORY IN EFFECT UNTIL 8 AM EDT /7 AM CDT/ THIS
MORNING...

.EARLY THIS MORNING...West winds 15 to 25 knots. Patchy dense
fog. Waves 1 to 3 feet.
.TODAY...West winds 10 to 20 knots backing southwest in the
afternoon. Waves 1 to 3 feet.
.TONIGHT...West winds 5 to 15 knots. Waves subsiding to calm to
2 feet.
.WEDNESDAY...West winds 5 to 15 knots backing south late. Waves
calm to 2 feet.
.WEDNESDAY NIGHT...Southwest winds 5 to 15 knots veering west
after midnight. A chance of showers. A slight chance of
thunderstorms after midnight. Waves calm to 2 feet.
.THURSDAY...East winds 10 to 20 knots backing northeast by mid
afternoon. A chance of showers through early afternoon. Showers
likely by mid afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...Northeast winds 5 to 15 knots. A chance of
showers. Waves calm to 2 feet.
.FRIDAY...Northeast winds 10 to 20 knots. A chance of showers,
then showers likely and a chance of thunderstorms. Waves calm to
2 feet.
.SATURDAY...Northeast winds 10 to 20 knots. A chance of showers.
Waves calm to 2 feet.

$$

LSZ263-172000-
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-
402 AM EDT Tue Jun 17 2025

...DENSE FOG ADVISORY IN EFFECT UNTIL 8 AM EDT THIS MORNING...

.EARLY THIS MORNING...West winds 15 to 25 knots. Patchy dense
fog. A slight chance of showers. Waves 1 to 3 feet building to
2 to 4 feet.
.TODAY...West winds 15 to 25 knots becoming southwest 10 to
20 knots in the afternoon. Waves subsiding to 1 to 3 feet.
.TONIGHT...Southwest winds 5 to 15 knots veering west after
midnight. Waves subsiding to calm to 2 feet.
.WEDNESDAY...West winds less than 10 knots becoming southwest
5 to 15 knots in the afternoon, then backing south late. Waves
calm to 2 feet.
.WEDNESDAY NIGHT...Southwest winds 5 to 15 knots veering west
after midnight. A slight chance of showers. A slight chance of
thunderstorms after midnight. Waves calm to 2 feet.
.THURSDAY...North winds 5 to 15 knots veering northeast by mid
afternoon. A chance of showers through early afternoon. Showers
likely by mid afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...Northeast winds 5 to 15 knots veering east
after midnight. A chance of showers. Waves calm to 2 feet.
.FRIDAY...East winds 5 to 15 knots. A chance of showers, then
showers likely and a chance of thunderstorms. Waves calm to
2 feet.
.SATURDAY...Northeast winds 5 to 15 knots veering east. A chance
of showers. Waves calm to 2 feet.

$$

LSZ264-172000-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
402 AM EDT Tue Jun 17 2025

...DENSE FOG ADVISORY IN EFFECT UNTIL 8 AM EDT THIS MORNING...

.EARLY THIS MORNING...Southwest winds 15 to 25 knots. Patchy
dense fog. A chance of showers and a slight chance of
thunderstorms. Waves 2 to 4 feet building to 3 to 5 feet
occasionally to 7 feet.
.TODAY...West winds 15 to 25 knots becoming southwest 10 to
20 knots late. Areas of dense fog through early afternoon. Waves
building to 3 to 6 feet occasionally to 8 feet, then subsiding to
1 to 3 feet.
.TONIGHT...Southwest winds 5 to 15 knots veering west after
midnight. Waves subsiding to calm to 2 feet.
.WEDNESDAY...West winds less than 10 knots becoming south 5 to
15 knots in the afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...South winds 5 to 15 knots veering west after
midnight. A slight chance of showers after midnight. Waves calm
to 2 feet.
.THURSDAY...North winds 5 to 15 knots. A chance of showers. Waves
calm to 2 feet.
.THURSDAY NIGHT...North winds 5 to 15 knots veering northeast
after midnight. Waves calm to 2 feet.
.FRIDAY...East winds 5 to 15 knots veering southeast. A chance of
showers. Waves calm to 2 feet.
.SATURDAY...East winds 5 to 15 knots veering southeast. A chance
of showers. Waves calm to 2 feet.

$$

LSZ265-172000-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
402 AM EDT Tue Jun 17 2025

.EARLY THIS MORNING...South winds 15 to 25 knots. A chance of
showers and a slight chance of thunderstorms. Waves 2 to 4 feet.
.TODAY...West winds 15 to 25 knots diminishing to 10 to 20 knots
late. Waves subsiding to calm to 2 feet.
.TONIGHT...Southwest winds 5 to 15 knots veering west late. Waves
calm to 2 feet.
.WEDNESDAY...West winds 5 to 15 knots backing east in the
afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...Southeast winds 5 to 15 knots veering west
after midnight. A slight chance of showers through midnight.
Waves calm to 2 feet.
.THURSDAY...Northwest winds 10 to 20 knots veering north by mid
afternoon. A chance of showers. Waves calm to 2 feet.
.THURSDAY NIGHT...Northwest winds 5 to 15 knots veering north
after midnight. A chance of showers. Waves calm to 2 feet.
.FRIDAY...East winds 10 to 20 knots veering southeast. A chance
of showers, then showers likely and a chance of thunderstorms.
Waves calm to 2 feet.
.SATURDAY...East winds 10 to 20 knots veering southeast. A chance
of showers. Waves calm to 2 feet.

$$

LSZ266-172000-
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-
402 AM EDT Tue Jun 17 2025

.EARLY THIS MORNING...South winds 20 to 30 knots. Patchy fog. A
chance of showers and thunderstorms. Waves 3 to 6 feet
occasionally to 8 feet.
.TODAY...West winds 15 to 25 knots diminishing to 10 to 20 knots
late. Patchy dense fog through early afternoon. A slight chance
of showers and thunderstorms through early afternoon. Waves
building to 4 to 7 feet occasionally to 9 feet, then subsiding to
2 to 4 feet.
.TONIGHT...Southwest winds 5 to 15 knots backing south after
midnight, then veering southwest late. Waves subsiding to calm to
2 feet.
.WEDNESDAY...West winds 5 to 15 knots veering northeast in the
afternoon, then veering east late. A slight chance of showers by
mid afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...East winds 5 to 15 knots backing northwest
after midnight. A chance of showers. Waves calm to 2 feet.
.THURSDAY...Northwest winds 10 to 20 knots. A chance of showers.
Waves calm to 2 feet.
.THURSDAY NIGHT...Northwest winds 5 to 15 knots veering north
after midnight. A chance of showers. Waves calm to 2 feet.
.FRIDAY...East winds 5 to 15 knots becoming southeast 10 to
20 knots. A chance of showers, then showers likely and a chance
of thunderstorms. Waves building to 1 to 3 feet.
.SATURDAY...East winds 10 to 20 knots veering southeast. A chance
of showers and thunderstorms. Waves subsiding to calm to 2 feet,
then building to 1 to 3 feet.

$$

LSZ267-172000-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
402 AM EDT Tue Jun 17 2025

.EARLY THIS MORNING...South winds 20 to 30 knots. A chance of
showers and thunderstorms. Waves 2 to 4 feet.
.TODAY...South winds 20 to 30 knots veering west in the
afternoon, then diminishing to 10 to 20 knots late. A chance of
showers and thunderstorms through early afternoon. Waves building
to 3 to 5 feet occasionally to 7 feet, then subsiding to 2 to
4 feet.
.TONIGHT...West winds 5 to 15 knots backing south after midnight.
Waves subsiding to calm to 2 feet.
.WEDNESDAY...South winds 5 to 15 knots backing north in the
afternoon, then veering northeast late. A slight chance of
showers by mid afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...North winds 5 to 15 knots becoming northwest
10 to 20 knots after midnight. A chance of showers. Waves calm to
2 feet.
.THURSDAY...Northwest winds 10 to 20 knots. A chance of showers.
Waves calm to 2 feet.
.THURSDAY NIGHT...Northwest winds 10 to 20 knots becoming north
5 to 15 knots after midnight. A chance of showers. Waves calm to
2 feet.
.FRIDAY...North winds 10 to 20 knots veering southeast. A chance
of showers, then showers likely. Waves calm to 2 feet.
.SATURDAY...Southeast winds 10 to 20 knots. A chance of showers
and thunderstorms. Waves building to 1 to 3 feet.

$$

LSZ261-171400-
MAFOR 1709/
Superior West 11630 19634 11630 11620 12520 11510 12610. Waves 1
to 3 feet.

Superior North Central 11530 19534 11644 12630 11620 12510 11610.
A chance of showers this morning. Waves 2 to 4 feet building to 3
to 6 feet, then subsiding to 2 to 4 feet today. Waves 2 to 4 feet
tonight.

Superior South Central 11430 12630 11620 11610 11500 11510 11500.
A chance of showers this morning. Waves 2 to 4 feet building to 3
to 5 feet, then subsiding to 2 to 3 feet today. Waves 2 feet or
less tonight.

Superior East 11446 11540 12630 11620 11610 12400. A chance of
thunderstorms this morning. Waves 3 to 6 feet today. Waves 3 to 5
feet subsiding to 1 to 3 feet tonight.

$$

WFO MQT

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weather.gov/mqt/glftable

Graphical marine forecasts are available online at:
weather.gov/greatlakes