842
FZUS63 KMQT 150803
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
403 AM EDT Tue Jul 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...

Today through tonight, a 29.7 inch low over the High Plains will
pass a 29.9 inch trough over Lake Superior. As the parent low
weakens to 29.8 inches and moves over Lakes Michigan and Huron
Wednesday, a 30.1 inch high pressure will build over the Northern
Plains. This high will maintain 30.1 inches as it slowly moves over
Lake Superior Thursday, briefly building to 30.2 inches over Lake
Huron Friday before reaching the Lower Great Lakes Saturday at 30.1
inches. Saturday evening, a 29.9 inch trough will move from the
Northern Plains over the lake before a 30.0 inch high is established
over Lake Superior Sunday.


LSZ162-152000-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
403 AM EDT Tue Jul 15 2025 /303 AM CDT Tue Jul 15 2025/

.EARLY THIS MORNING...Northeast winds 10 to 20 knots. Haze. A
chance of showers and thunderstorms. Waves calm to 2 feet.
.TODAY...Northeast winds 10 to 20 knots backing west late. Haze
through early afternoon. A chance of showers and thunderstorms
through early afternoon, then showers and thunderstorms likely by
mid afternoon. Waves calm to 2 feet.
.TONIGHT...North winds 10 to 20 knots veering northeast after
midnight, then increasing to 15 to 25 knots late. A chance of
showers and thunderstorms through midnight, then showers likely
after midnight. Waves building to 2 to 4 feet.
.WEDNESDAY...Northeast winds 15 to 25 knots becoming east 10 to
20 knots late. Showers likely and a slight chance of
thunderstorms through early afternoon, then a chance of showers
by mid afternoon. Waves building to 3 to 5 feet occasionally to
7 feet, then subsiding to 2 to 4 feet.
.WEDNESDAY NIGHT...Northeast winds 10 to 20 knots backing north
after midnight. A chance of showers. Waves subsiding to calm to
2 feet.
.THURSDAY...North winds 10 to 20 knots becoming southwest 5 to
15 knots by mid afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...Southwest winds 5 to 15 knots. Waves calm to
2 feet.
.FRIDAY...Southwest winds 5 to 15 knots backing east. A chance of
showers. Waves calm to 2 feet.
.SATURDAY...East winds 10 to 20 knots becoming northeast 5 to
15 knots. A chance of showers. Waves 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-
403 AM EDT Tue Jul 15 2025

.EARLY THIS MORNING...East winds 5 to 15 knots. Haze. A chance of
showers and thunderstorms. Waves calm to 2 feet.
.TODAY...South winds 5 to 15 knots veering west in the afternoon.
Haze. A chance of showers and thunderstorms through early
afternoon. Showers and thunderstorms likely by mid afternoon.
Waves calm to 2 feet.
.TONIGHT...North winds 5 to 15 knots becoming northeast 10 to
20 knots after midnight, then increasing to 15 to 25 knots late.
Haze through midnight. Showers likely and a chance of
thunderstorms through midnight, then a chance of showers after
midnight. Waves building to 2 to 4 feet.
.WEDNESDAY...Northeast winds 15 to 25 knots diminishing to 10 to
20 knots late. Showers likely through early afternoon. A slight
chance of thunderstorms. A chance of showers by mid afternoon.
Waves building to 3 to 5 feet occasionally to 7 feet, then
subsiding to 2 to 4 feet.
.WEDNESDAY NIGHT...Northeast winds 5 to 15 knots backing north
after midnight. A chance of showers. Waves subsiding to calm to
2 feet.
.THURSDAY...North winds 5 to 15 knots backing southwest by mid
afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...Southwest winds 5 to 15 knots. Waves calm to
2 feet.
.FRIDAY...Southwest winds 5 to 15 knots backing south. A chance
of showers. Waves calm to 2 feet.
.SATURDAY...East winds 5 to 15 knots backing northeast. A chance
of showers. Waves calm to 2 feet.

$$

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

.EARLY THIS MORNING...Southeast winds 5 to 15 knots. Haze and
areas of smoke. A chance of showers and a slight chance of
thunderstorms. Waves calm to 2 feet.
.TODAY...Southeast winds 5 to 15 knots veering southwest in the
afternoon, then veering west late. Areas of smoke through early
afternoon. Haze. Showers likely and a chance of thunderstorms.
Waves calm to 2 feet.
.TONIGHT...North winds 5 to 15 knots increasing to 10 to 20 knots
after midnight. Haze through midnight. A chance of thunderstorms
through midnight. A chance of showers. Waves building to 2 to
4 feet.
.WEDNESDAY...Northeast winds 10 to 20 knots. A chance of showers.
Waves subsiding to calm to 2 feet.
.WEDNESDAY NIGHT...North winds 5 to 15 knots. A chance of
showers. Waves calm to 2 feet.
.THURSDAY...North winds 5 to 15 knots backing west by mid
afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...West winds 5 to 15 knots backing southwest
after midnight. Waves calm to 2 feet.
.FRIDAY...Southwest winds 5 to 15 knots backing south. A chance
of showers. Waves calm to 2 feet.
.SATURDAY...East winds 5 to 15 knots backing north. A chance of
showers. Waves calm to 2 feet.

$$

LSZ265-152000-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
403 AM EDT Tue Jul 15 2025

.EARLY THIS MORNING...Southeast winds 10 to 20 knots. Areas of
smoke. A slight chance of showers and thunderstorms. Waves calm
to 2 feet.
.TODAY...South winds 10 to 20 knots backing north late. Haze
through early afternoon. A chance of thunderstorms through early
afternoon. A chance of showers. Thunderstorms likely by mid
afternoon. Waves calm to 2 feet.
.TONIGHT...North winds 10 to 20 knots. Showers likely and a
chance of thunderstorms through midnight, then a chance of
showers after midnight. Waves building to 1 to 3 feet.
.WEDNESDAY...North winds 10 to 20 knots becoming northeast 15 to
25 knots in the afternoon. Showers likely and a slight chance of
thunderstorms through early afternoon, then a chance of showers
by mid afternoon. Waves building to 2 to 4 feet, then subsiding
to 1 to 3 feet.
.WEDNESDAY NIGHT...North winds 10 to 20 knots. A chance of
showers and a slight chance of thunderstorms through midnight,
then showers likely after midnight. Waves subsiding to calm to
2 feet.
.THURSDAY...North winds 10 to 20 knots backing northwest by mid
afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...West winds 5 to 15 knots. Waves calm to 2 feet.
.FRIDAY...Southwest winds 5 to 15 knots becoming south 10 to
20 knots. A chance of showers. Waves calm to 2 feet.
.SATURDAY...Southeast winds 10 to 20 knots becoming northwest
5 to 15 knots. A chance of showers. Waves 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-
403 AM EDT Tue Jul 15 2025

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

$$

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

.EARLY THIS MORNING...Southeast winds 10 to 20 knots. Haze. Waves
calm to 2 feet.
.TODAY...South winds 10 to 20 knots veering southwest late. Haze
through early afternoon. A chance of showers and thunderstorms.
Waves calm to 2 feet.
.TONIGHT...West winds 10 to 20 knots becoming north 5 to 15 knots
late. A chance of showers and thunderstorms. Waves calm to
2 feet.
.WEDNESDAY...North winds 10 to 20 knots veering northeast late.
Showers likely and a slight chance of thunderstorms. Waves
building to 2 to 4 feet.
.WEDNESDAY NIGHT...Northeast winds 15 to 25 knots backing north
after midnight. A chance of showers through midnight. A slight
chance of thunderstorms. Showers likely after midnight. Waves
2 to 4 feet.
.THURSDAY...North winds 15 to 25 knots becoming northwest 10 to
20 knots by mid afternoon. A chance of showers through early
afternoon. Waves subsiding to calm to 2 feet.
.THURSDAY NIGHT...Northwest winds 10 to 20 knots becoming west
5 to 15 knots after midnight. Waves calm to 2 feet.
.FRIDAY...Southwest winds 5 to 15 knots backing south. Waves calm
to 2 feet.
.SATURDAY...Southeast winds 10 to 20 knots veering south. A
chance of showers. Waves calm to 2 feet.

$$

LSZ261-151400-
MAFOR 1509/
Superior West 12210 11110 11119 11619 11816 11126 11136. Waves 1
to 2 feet today. Waves 1 to 3 feet building to 2 to 4 feet
tonight.

Superior North Central 11310 11320 11416 11516 11606 11716 12820.
A chance of thunderstorms today and this evening. Waves 1 to 3
feet.

Superior South Central 11310 12410 11210 11819 11106 11800 11820.
Waves 1 to 2 feet.

Superior East 12310 12410 11516 11716 11600 11710. A chance of
thunderstorms this afternoon and tonight. Waves 1 to 2 feet.

$$

WFO MQT

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weather.gov/mqt/glftable

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