211
FZUS63 KMQT 111402
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1002 AM EDT Mon Aug 11 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 29.9 inch trough remains over Lake Superior as a 29.6 inch low
moving into Hudson Bay weakens and a 29.5 inch low over northern
Manitoba digs southeast early this week. This second low moves into
northern Ontario and Hudson Bay late tonight and Tuesday, pulling a
29.7 inch trough through Lake Superior. A 30.1 inch high pressure
then moves out of Manitoba Wednesday while stretching 30.0 inch
ridging into the Upper Great Lakes. This builds to 30.1 inches on
Thursday as the high transits Ontario into Quebec. By Friday, a 29.5
inch low moving over northern Ontario into Hudson Bay is expected to
bring 29.9 inch troughing back over Lake Superior.


LSZ162-112000-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1002 AM EDT Mon Aug 11 2025 /902 AM CDT Mon Aug 11 2025/

.REST OF TODAY...Southwest winds 10 to 20 knots diminishing to
5 to 15 knots in the afternoon, then backing south late. Waves
calm to 2 feet.
.TONIGHT...South winds 10 to 20 knots veering southwest after
midnight, then increasing to 15 to 25 knots late. Haze. A slight
chance of showers. A slight chance of thunderstorms after
midnight. Waves building to 2 to 4 feet.
.TUESDAY...Southwest winds 15 to 25 knots veering west late. A
slight chance of showers. A slight chance of thunderstorms by mid
afternoon. Waves subsiding to 1 to 3 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots veering northwest
after midnight. Waves subsiding to calm to 2 feet.
.WEDNESDAY...Northwest winds 10 to 20 knots becoming south 5 to
15 knots by mid afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...East winds 5 to 15 knots increasing to 10 to
20 knots after midnight. Waves calm to 2 feet.
.THURSDAY...East winds 10 to 20 knots veering south. A chance of
showers and thunderstorms. Waves calm to 2 feet.
.FRIDAY...Southwest winds 10 to 20 knots veering west. A chance
of showers. Waves calm to 2 feet.

$$

LSZ263-112000-
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-
1002 AM EDT Mon Aug 11 2025

.REST OF TODAY...West winds 5 to 15 knots becoming southwest
10 to 20 knots in the afternoon. Waves calm to 2 feet.
.TONIGHT...South winds 5 to 15 knots increasing to 10 to 20 knots
after midnight, then veering southwest late. Haze. A slight
chance of showers and thunderstorms after midnight. Waves
building to 2 to 4 feet.
.TUESDAY...Southwest winds 15 to 25 knots veering west late. A
slight chance of showers and thunderstorms. Waves building to
3 to 5 feet occasionally to 7 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots veering northwest
after midnight. Waves subsiding to 1 to 3 feet.
.WEDNESDAY...Northwest winds 5 to 15 knots backing southwest by
mid afternoon. Waves subsiding to calm to 2 feet.
.WEDNESDAY NIGHT...East winds 5 to 15 knots. Waves calm to
2 feet.
.THURSDAY...Southeast winds 10 to 20 knots veering south. A
chance of showers. Waves building to 1 to 3 feet.
.FRIDAY...Southwest winds 10 to 20 knots becoming west 5 to
15 knots. A chance of showers. Waves subsiding to calm to 2 feet.

$$

LSZ264-112000-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
1002 AM EDT Mon Aug 11 2025

.REST OF TODAY...West winds 5 to 15 knots backing southwest in
the afternoon. Waves calm to 2 feet.
.TONIGHT...South winds 5 to 15 knots increasing to 10 to 20 knots
late. Haze. Waves building to 1 to 3 feet.
.TUESDAY...Southwest winds 15 to 25 knots veering west late. A
slight chance of showers and thunderstorms. Waves building to
3 to 5 feet occasionally to 7 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots veering northwest
after midnight. Waves subsiding to 1 to 3 feet.
.WEDNESDAY...Northwest winds 5 to 15 knots backing west by mid
afternoon. Waves subsiding to calm to 2 feet.
.WEDNESDAY NIGHT...North winds 5 to 15 knots veering east after
midnight. Waves calm to 2 feet.
.THURSDAY...Southeast winds 10 to 20 knots veering south. A
chance of showers. Waves building to 1 to 3 feet.
.FRIDAY...Southwest winds 10 to 20 knots becoming west 5 to
15 knots. A chance of showers. Waves subsiding to calm to 2 feet.

$$

LSZ265-112000-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1002 AM EDT Mon Aug 11 2025

.REST OF TODAY...West winds 5 to 15 knots increasing to 10 to
20 knots in the afternoon, then diminishing to 5 to 15 knots
late. Waves calm to 2 feet.
.TONIGHT...Southeast winds 5 to 15 knots veering south after
midnight, then increasing to 10 to 20 knots late. Haze after
midnight. Waves calm to 2 feet.
.TUESDAY...Southwest winds 10 to 20 knots becoming west 15 to
25 knots in the afternoon, then diminishing to 10 to 20 knots
late. A chance of showers and thunderstorms. Waves calm to
2 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots increasing to 15 to
25 knots after midnight. Waves calm to 2 feet.
.WEDNESDAY...Northwest winds 10 to 20 knots veering north by mid
afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...North winds 5 to 15 knots veering east after
midnight. Waves calm to 2 feet.
.THURSDAY...Southeast winds 10 to 20 knots veering south. A
chance of showers. Waves calm to 2 feet.
.FRIDAY...South winds 10 to 20 knots veering southwest. A chance
of showers. Waves calm to 2 feet.

$$

LSZ266-112000-
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-
1002 AM EDT Mon Aug 11 2025

.REST OF TODAY...West winds 5 to 15 knots. Waves calm to 2 feet.
.TONIGHT...Southeast winds 5 to 15 knots veering south after
midnight, then increasing to 10 to 20 knots late. Haze after
midnight. Waves calm to 2 feet.
.TUESDAY...South winds 15 to 25 knots veering southwest in the
afternoon, then becoming west 10 to 20 knots late. A chance of
showers and thunderstorms. Waves building to 3 to 5 feet
occasionally to 7 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots becoming northwest
15 to 25 knots after midnight. Waves subsiding to 1 to 3 feet.
.WEDNESDAY...Northwest winds 10 to 20 knots. Waves 1 to 3 feet.
.WEDNESDAY NIGHT...North winds 5 to 15 knots veering northeast
after midnight. Waves subsiding to calm to 2 feet.
.THURSDAY...East winds 5 to 15 knots becoming south 10 to
20 knots. Waves building to 1 to 3 feet.
.FRIDAY...South winds 15 to 25 knots becoming southwest 10 to
20 knots. A chance of showers. Waves subsiding to calm to 2 feet.

$$

LSZ267-112000-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1002 AM EDT Mon Aug 11 2025

.REST OF TODAY...Southwest winds 10 to 20 knots veering west in
the afternoon, then diminishing to 5 to 15 knots late. A slight
chance of thunderstorms by late morning. A chance of showers.
Waves calm to 2 feet.
.TONIGHT...South winds 5 to 15 knots increasing to 10 to 20 knots
after midnight. Patchy fog through midnight. A slight chance of
showers through midnight. Waves calm to 2 feet.
.TUESDAY...South winds 10 to 20 knots veering west late. A slight
chance of showers through early afternoon, then showers likely
and a chance of thunderstorms by mid afternoon. Waves calm to
2 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots. A slight chance of
showers and thunderstorms through midnight. Waves building to
1 to 3 feet.
.WEDNESDAY...Northwest winds 10 to 20 knots. Waves 1 to 3 feet.
.WEDNESDAY NIGHT...Northwest winds 10 to 20 knots veering
northeast after midnight. Waves subsiding to calm to 2 feet.
.THURSDAY...East winds 10 to 20 knots veering south. Waves calm
to 2 feet.
.FRIDAY...South winds 10 to 20 knots. A chance of showers. Waves
building to 1 to 3 feet, then subsiding to calm to 2 feet.

$$

LSZ261-112000-
MAFOR 1115/
Superior West 12510 12410 11420 11520 12530. Waves 1 to 3 feet
this afternoon and tonight. Waves 2 to 4 feet Tuesday morning.

Superior North Central 11610 13510 12410 11420 11520. Waves 1 to
3 feet.

Superior South Central 11610 11710 11800 11300 11400 13410. Waves
2 feet or less.

Superior East 11500 11600 11500 12400 12410 11420. Waves 1 to 2
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