998
FZUS63 KMQT 110801
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
401 AM EDT Tue Aug 11 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...

This morning, Lake Superior is under weak 29.9 inch ridging broadly
associated with 30.1 inch high pressure over the Appalachians while
29.6 inch low pressure is over Labrador and 29.8 inch low pressure
is over the Central Plains. By tonight, the Labrador low descends to
the Gulf of St Lawrence and deepens to 29.5 inches while the Plains
low deepens to 29.7 inches, eroding the ridge over Lake Superior to
29.8 inches. This pattern holds until Thursday morning, when a 30.2
inch high over the Canadian Rockies begins to extend stronger
ridging over Lake Superior before eventually becoming centered over
the lake Friday afternoon. A 29.9 inch trough then moves over the
western end of the lake Saturday afternoon as the 30.2 inch high
moves over the Lower Great Lakes. This trough consolidates to a 29.8
inch low as it passes over the lake, reaching Ontario by Sunday
afternoon, with 30.1 inch ridging to follow.



LSZ162-112000-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
401 AM EDT Tue Aug 11 2026 /301 AM CDT Tue Aug 11 2026/

.EARLY THIS MORNING...North winds less than 10 knots. Waves calm
to 2 feet.
.TODAY...North winds less than 10 knots veering east in the
afternoon, then becoming southeast 5 to 15 knots late. A slight
chance of showers through early afternoon. Waves calm to 2 feet.
.TONIGHT...Southeast winds less than 10 knots veering west after
midnight, then becoming north 5 to 15 knots late. Waves calm to
2 feet.
.WEDNESDAY...North winds 5 to 15 knots veering south in the
afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...Northeast winds 5 to 15 knots backing
northwest after midnight. Waves calm to 2 feet.
.THURSDAY...Northwest winds 5 to 15 knots backing south by mid
afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...East winds 5 to 15 knots backing northeast
after midnight. Waves calm to 2 feet.
.FRIDAY...East winds 10 to 20 knots. Waves calm to 2 feet.
.SATURDAY...East winds 10 to 20 knots backing northeast. 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-
401 AM EDT Tue Aug 11 2026

.EARLY THIS MORNING...West winds less than 10 knots. Waves calm
to 2 feet.
.TODAY...West winds less than 10 knots becoming south 5 to
15 knots in the afternoon. A slight chance of showers. Waves calm
to 2 feet.
.TONIGHT...South winds 5 to 15 knots becoming west less than
10 knots after midnight, then backing southwest late. Waves calm
to 2 feet.
.WEDNESDAY...North winds less than 10 knots becoming northwest
5 to 15 knots in the afternoon, then backing south late. Waves
calm to 2 feet.
.WEDNESDAY NIGHT...West winds less than 10 knots increasing to
5 to 15 knots after midnight. Waves calm to 2 feet.
.THURSDAY...North winds 5 to 15 knots veering south by mid
afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...East winds less than 10 knots backing north
after midnight. Waves calm to 2 feet.
.FRIDAY...Northeast winds 5 to 15 knots veering southeast. Waves
calm to 2 feet.
.SATURDAY...East winds 5 to 15 knots. A chance of showers. Waves
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-
401 AM EDT Tue Aug 11 2026

.EARLY THIS MORNING...West winds less than 10 knots. Waves calm
to 2 feet.
.TODAY...West winds less than 10 knots backing south late. Waves
calm to 2 feet.
.TONIGHT...South winds less than 10 knots veering southwest after
midnight, then backing south late. Waves calm to 2 feet.
.WEDNESDAY...North winds less than 10 knots backing northwest in
the afternoon, then backing southwest late. Waves calm to 2 feet.
.WEDNESDAY NIGHT...West winds less than 10 knots. Waves calm to
2 feet.
.THURSDAY...Northwest winds 5 to 15 knots diminishing to less
than 10 knots by mid afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...Northwest winds 5 to 15 knots becoming north
less than 10 knots after midnight. Waves calm to 2 feet.
.FRIDAY...North winds less than 10 knots becoming south 5 to
15 knots. Waves calm to 2 feet.
.SATURDAY...Southeast winds 5 to 15 knots. A chance of showers.
Waves calm to 2 feet.

$$

LSZ265-112000-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
401 AM EDT Tue Aug 11 2026

.EARLY THIS MORNING...West winds 10 to 20 knots. Waves calm to
2 feet.
.TODAY...West winds 5 to 15 knots backing east in the afternoon.
A slight chance of showers. Waves calm to 2 feet.
.TONIGHT...South winds 5 to 15 knots. Waves calm to 2 feet.
.WEDNESDAY...South winds 5 to 15 knots backing north in the
afternoon, then veering northeast late. Waves calm to 2 feet.
.WEDNESDAY NIGHT...West winds 5 to 15 knots. Waves calm to
2 feet.
.THURSDAY...Northwest winds 10 to 20 knots veering north by mid
afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...North winds 5 to 15 knots. Waves calm to
2 feet.
.FRIDAY...Northeast winds 5 to 15 knots veering southeast. Waves
calm to 2 feet.
.SATURDAY...Southeast winds 10 to 20 knots. 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-
401 AM EDT Tue Aug 11 2026

.EARLY THIS MORNING...Southwest winds 5 to 15 knots. Patchy fog.
Waves calm to 2 feet.
.TODAY...West winds 5 to 15 knots backing south in the afternoon,
then backing east late. A slight chance of showers by mid
afternoon. Waves calm to 2 feet.
.TONIGHT...South winds less than 10 knots becoming north 5 to
15 knots after midnight, then veering east late. Waves calm to
2 feet.
.WEDNESDAY...Southeast winds 5 to 15 knots backing north in the
afternoon, then backing northwest late. Waves calm to 2 feet.
.WEDNESDAY NIGHT...Northwest winds 5 to 15 knots. Waves calm to
2 feet.
.THURSDAY...Northwest winds 5 to 15 knots. Waves calm to 2 feet.
.THURSDAY NIGHT...Northwest winds 10 to 20 knots becoming north
5 to 15 knots after midnight. Waves calm to 2 feet.
.FRIDAY...North winds 5 to 15 knots veering southeast. Waves calm
to 2 feet.
.SATURDAY...Southeast winds 10 to 20 knots. A chance of showers.
Waves calm to 2 feet.

$$

LSZ267-112000-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
401 AM EDT Tue Aug 11 2026

.EARLY THIS MORNING...South winds 5 to 15 knots. Patchy fog.
Waves calm to 2 feet.
.TODAY...Southeast winds 5 to 15 knots veering south in the
afternoon, then backing north late. Patchy dense fog through
early afternoon. Waves calm to 2 feet.
.TONIGHT...West winds 5 to 15 knots becoming northwest less than
10 knots after midnight, then veering north late. Waves calm to
2 feet.
.WEDNESDAY...North winds 5 to 15 knots backing northwest late.
Waves calm to 2 feet.
.WEDNESDAY NIGHT...Northwest winds 5 to 15 knots. Waves calm to
2 feet.
.THURSDAY...Northwest winds 5 to 15 knots increasing to 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...Northwest winds 10 to 20 knots veering north
after midnight. Waves calm to 2 feet.
.FRIDAY...Northwest winds 5 to 15 knots backing southeast. Waves
calm to 2 feet.
.SATURDAY...Southeast winds 5 to 15 knots increasing to 10 to
20 knots. A chance of showers. Waves calm to 2 feet.

$$

LSZ261-111400-
MAFOR 1109/
Superior West 12700 11800 11200 12300 12700. Waves 1 foot or
less.

Superior North Central 13600 13400 11500 11400. Waves 1 foot or
less.

Superior South Central 11500 11600 11700 12200 11300 11400 11200.
Waves 1 foot or less.

Superior East 11400 11300 19304 12400 11700 11600 11700 11800.
Waves 1 foot or less.

$$

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