864
FZUS63 KMQT 170201
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1001 PM EDT Sun Aug 16 2026

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 30.1 inch high pressure expands over the Midwest tonight,
extending a 30.0 inch ridge over Lake Superior. This high weakens to
30.0 inches on Monday and shifts south as a 29.8 inch trough,
associated with a 29.6 inch low over the Hudson Bay, builds over
Lake Superior. Troughing lingers until Tuesday afternoon when weak
29.9 inch ridging returns to Lake Superior. 30.0 inch high pressure
settles over the Northern Plains Tuesday afternoon and night,
eventually moving over Lake Superior Wednesday evening before
expanding to cover much of the Great Lakes by Thursday afternoon.
Friday into the weekend, a low pressure of around 29.8 inches
transits across northern Ontario.



LSZ162-170800-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1001 PM EDT Sun Aug 16 2026 /901 PM CDT Sun Aug 16 2026/

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

$$

LSZ263-170800-
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 PM EDT Sun Aug 16 2026

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

$$

LSZ264-170800-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
1001 PM EDT Sun Aug 16 2026

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

$$

LSZ265-170800-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1001 PM EDT Sun Aug 16 2026

.REST OF TONIGHT...West winds 10 to 20 knots. Waves calm to
2 feet.
.MONDAY...West winds 10 to 20 knots becoming southwest 5 to
15 knots late. Waves calm to 2 feet.
.MONDAY NIGHT...South winds 10 to 20 knots veering southwest
after midnight, then becoming west 15 to 25 knots late. A chance
of showers. Waves calm to 2 feet.
.TUESDAY...West winds 15 to 25 knots. Waves building to 2 to
4 feet, then 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 veering north by mid
afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...Southwest winds 5 to 15 knots veering west
after midnight. Waves calm to 2 feet.
.THURSDAY...Southeast winds 5 to 15 knots becoming south 10 to
20 knots. Waves calm to 2 feet.
.FRIDAY...Southwest winds 10 to 20 knots veering northwest. A
chance of showers. Waves calm to 2 feet.

$$

LSZ266-170800-
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 PM EDT Sun Aug 16 2026

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

$$

LSZ267-170800-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1001 PM EDT Sun Aug 16 2026

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

$$

LSZ261-170800-
MAFOR 1703/
Superior West 12710 12600 11510 11520 11420 11520. A chance of
showers Monday evening. Waves 2 feet or less.

Superior North Central 14600 11610 13520. Waves 1 to 3 feet.

Superior South Central 11720 14610 11610 11510 11410. Waves 1 to
3 feet overnight and Monday. Waves 1 foot or less Monday evening.

Superior East 11720 12710 11700 12600 11500 11400. Waves 3 to 5
feet subsiding to 2 to 3 feet overnight. Waves 1 to 3 feet Monday
and Monday evening.

$$

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