901
FZUS63 KMQT 170802
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
402 AM EDT Thu Jul 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...

Lake Superior is between a low pressure of 29.7 inches over Lake
Huron and a high of 30.1 inches over the Dakotas. As the low races
up the St Lawrence Seaway today, the high pressure will settle over
the Upper Great Lakes, remaining at 30.1 inches through late Friday.
Early Saturday, a weak 29.9 inch trough will sweep across the lake
before being replaced with another 30.1 inch high Sunday. As the low
shifts towards the Lower Great Lakes through Tuesday morning, it
builds to 30.2 inches. Meanwhile, a pair of lows will begin shifting
towards the Great Lakes, one over the Central Plains and one over
Hudson Bay, both at around 29.6 inches.


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

.EARLY THIS MORNING...North winds 5 to 15 knots. Waves calm to
2 feet.
.TODAY...Northwest winds 5 to 15 knots backing southwest in the
afternoon. Waves calm to 2 feet.
.TONIGHT...Southwest winds 5 to 15 knots. Waves calm to 2 feet.
.FRIDAY...Southwest winds 5 to 15 knots increasing to 10 to
20 knots late. A chance of showers. A slight chance of
thunderstorms by mid afternoon. Waves calm to 2 feet.
.FRIDAY NIGHT...East winds 5 to 15 knots backing northeast after
midnight. A chance of showers and a slight chance of
thunderstorms. Waves calm to 2 feet.
.SATURDAY...Northeast winds 5 to 15 knots veering southwest by
mid afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...West winds 5 to 15 knots veering north after
midnight. Waves calm to 2 feet.
.SUNDAY...East winds 5 to 15 knots. Waves calm to 2 feet.
.MONDAY...East winds 10 to 20 knots becoming northeast 5 to
15 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 Thu Jul 17 2025

.EARLY THIS MORNING...Northwest winds 5 to 15 knots. Waves calm
to 2 feet.
.TODAY...West winds 5 to 15 knots backing southwest in the
afternoon. Waves calm to 2 feet.
.TONIGHT...Southwest winds 5 to 15 knots. Waves calm to 2 feet.
.FRIDAY...Southwest winds 5 to 15 knots. A chance of showers.
Waves calm to 2 feet.
.FRIDAY NIGHT...Southwest winds 5 to 15 knots backing northeast
after midnight. A chance of showers. A slight chance of
thunderstorms after midnight. Waves calm to 2 feet.
.SATURDAY...Northeast winds 5 to 15 knots veering southwest by
mid afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...West winds 5 to 15 knots diminishing to less
than 10 knots after midnight. Waves calm to 2 feet.
.SUNDAY...East winds 5 to 15 knots. Waves calm to 2 feet.
.MONDAY...East winds 5 to 15 knots veering south. 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 Thu Jul 17 2025

.EARLY THIS MORNING...North winds 5 to 15 knots. Waves 1 to
3 feet subsiding to calm to 2 feet.
.TODAY...Northwest winds 5 to 15 knots backing southwest in the
afternoon. Waves calm to 2 feet.
.TONIGHT...Southwest winds 5 to 15 knots. Waves calm to 2 feet.
.FRIDAY...Southwest winds 5 to 15 knots. A slight chance of
showers by mid afternoon. Waves calm to 2 feet.
.FRIDAY NIGHT...Southwest winds 5 to 15 knots diminishing to less
than 10 knots after midnight. A chance of showers. Waves calm to
2 feet.
.SATURDAY...Southwest winds 5 to 15 knots. Waves calm to 2 feet.
.SATURDAY NIGHT...West winds 5 to 15 knots diminishing to less
than 10 knots after midnight. Waves calm to 2 feet.
.SUNDAY...South winds 5 to 15 knots backing southeast. Waves calm
to 2 feet.
.MONDAY...Southeast winds 5 to 15 knots veering south. 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 Thu Jul 17 2025

.EARLY THIS MORNING...North winds 10 to 20 knots. A slight chance
of showers. Waves 3 to 5 feet occasionally to 7 feet.
.TODAY...North winds 10 to 20 knots becoming west 5 to 15 knots
in the afternoon. Waves subsiding to calm to 2 feet.
.TONIGHT...West winds 5 to 15 knots backing southwest late. Waves
calm to 2 feet.
.FRIDAY...Southwest winds 10 to 20 knots backing south in the
afternoon. A slight chance of showers by mid afternoon. Waves
calm to 2 feet.
.FRIDAY NIGHT...South winds 5 to 15 knots. A chance of showers.
Waves calm to 2 feet.
.SATURDAY...Southeast winds 5 to 15 knots becoming east 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...West winds 5 to 15 knots. Waves calm to 2 feet.
.SUNDAY...East winds 5 to 15 knots veering southeast. Waves calm
to 2 feet.
.MONDAY...Southeast winds 10 to 20 knots veering south. 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 Thu Jul 17 2025

.EARLY THIS MORNING...North winds 15 to 25 knots. A chance of
showers. Waves 3 to 6 feet occasionally to 8 feet.
.TODAY...North winds 10 to 20 knots becoming northwest 5 to
15 knots in the afternoon, then backing west late. Waves
subsiding to calm to 2 feet.
.TONIGHT...West winds 5 to 15 knots becoming southwest 10 to
20 knots late. Waves calm to 2 feet.
.FRIDAY...Southwest winds 10 to 20 knots becoming south 5 to
15 knots late. Waves calm to 2 feet.
.FRIDAY NIGHT...South winds 5 to 15 knots. A chance of showers.
Waves calm to 2 feet.
.SATURDAY...South winds 5 to 15 knots backing northeast by mid
afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...Northwest winds 5 to 15 knots. Waves calm to
2 feet.
.SUNDAY...North winds 5 to 15 knots veering southeast. Waves calm
to 2 feet.
.MONDAY...Southeast winds 10 to 20 knots veering south. Waves
calm to 2 feet.

$$

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

.EARLY THIS MORNING...North winds 15 to 25 knots. A chance of
showers. Waves 3 to 6 feet occasionally to 8 feet.
.TODAY...North winds 15 to 25 knots becoming northwest 10 to
20 knots in the afternoon. Waves subsiding to calm to 2 feet.
.TONIGHT...West winds 5 to 15 knots backing southwest late. Waves
calm to 2 feet.
.FRIDAY...Southwest winds 5 to 15 knots backing southeast late.
Waves calm to 2 feet.
.FRIDAY NIGHT...South winds 5 to 15 knots. A chance of showers.
Waves calm to 2 feet.
.SATURDAY...South winds 5 to 15 knots becoming north 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...Northwest winds 10 to 20 knots diminishing to
5 to 15 knots after midnight. Waves calm to 2 feet.
.SUNDAY...Northwest winds 5 to 15 knots backing southeast. Waves
calm to 2 feet.
.MONDAY...Southeast winds 10 to 20 knots. A chance of showers.
Waves calm to 2 feet.

$$

LSZ261-171400-
MAFOR 1709/
Superior West 12700 11600 12510 13500. Waves 1 to 2 feet.

Superior North Central 11800 11700 11600 13610 12510. Waves 1 to
3 feet.

Superior South Central 12820 11710 11700 13600 11500. A chance of
showers early this morning. Waves 3 to 5 feet subsiding to 1 to 3
feet today. Waves 1 foot or less tonight.

Superior East 11830 11820 11720 12710 11610 11600 11500. A chance
of showers this morning. Waves 3 to 5 feet subsiding to 2 to 4
feet today. Waves 1 to 2 feet tonight.

$$

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