657
FZUS63 KMQT 112001
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
401 PM 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...

Lake Superior remains under weak 29.9 inch ridging broadly
associated with 30.1 inch high pressure over the Southern
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 at 30.2 inches 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 Eastern
Great Lakes. This trough consolidates to a 29.8 inch low as it
passes over Lake Superior, reaching Ontario by Sunday afternoon,
with 30.1 inch ridging to follow.



LSZ162-120800-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
401 PM EDT Tue Aug 11 2026 /301 PM CDT Tue Aug 11 2026/

.LATE THIS AFTERNOON...South winds 5 to 15 knots. Waves calm to
2 feet.
.TONIGHT...East winds 5 to 15 knots backing northeast after
midnight, then becoming northwest less than 10 knots late. Patchy
fog after midnight. Waves calm to 2 feet.
.WEDNESDAY...Northwest winds less than 10 knots becoming
southwest 5 to 15 knots in the afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...Northeast winds 5 to 15 knots. A slight chance
of showers after midnight. Waves calm to 2 feet.
.THURSDAY...Northeast winds 5 to 15 knots veering east by mid
afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...Northeast winds 5 to 15 knots. Waves calm to
2 feet.
.FRIDAY...Northeast winds 10 to 20 knots increasing to 15 to
25 knots by mid afternoon. Waves building to 1 to 3 feet.
.FRIDAY NIGHT...East winds 15 to 25 knots diminishing to 10 to
20 knots after midnight. Waves subsiding to calm to 2 feet.
.SATURDAY...East winds 10 to 20 knots becoming northwest 5 to
15 knots. A chance of showers. Waves calm to 2 feet.
.SUNDAY...West winds 5 to 15 knots. Waves calm to 2 feet.

$$

LSZ263-120800-
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 PM EDT Tue Aug 11 2026

.LATE THIS AFTERNOON...South winds 5 to 15 knots. Waves calm to
2 feet.
.TONIGHT...East winds 5 to 15 knots becoming southwest less than
10 knots after midnight, then veering west late. Waves calm to
2 feet.
.WEDNESDAY...West winds less than 10 knots increasing to 5 to
15 knots in the afternoon, then backing south late. Waves calm to
2 feet.
.WEDNESDAY NIGHT...East winds 5 to 15 knots becoming northeast
less than 10 knots after midnight. A slight chance of showers
after midnight. Waves calm to 2 feet.
.THURSDAY...Northeast winds 5 to 15 knots veering east by mid
afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...Northeast winds 5 to 15 knots. Waves calm to
2 feet.
.FRIDAY...East winds 5 to 15 knots increasing to 15 to 25 knots
by mid afternoon. Waves calm to 2 feet.
.FRIDAY NIGHT...East winds 10 to 20 knots becoming southeast 5 to
15 knots after midnight. Waves calm to 2 feet.
.SATURDAY...East winds 5 to 15 knots backing northwest. A chance
of showers. Waves calm to 2 feet.
.SUNDAY...West winds 5 to 15 knots. Waves calm to 2 feet.

$$

LSZ264-120800-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
401 PM EDT Tue Aug 11 2026

.LATE THIS AFTERNOON...South winds less than 10 knots. Waves calm
to 2 feet.
.TONIGHT...Southwest winds less than 10 knots veering west late.
Waves calm to 2 feet.
.WEDNESDAY...West winds less than 10 knots veering northwest
late. Waves calm to 2 feet.
.WEDNESDAY NIGHT...West winds less than 10 knots veering
northwest late. Waves calm to 2 feet.
.THURSDAY...North winds less than 10 knots. Waves calm to 2 feet.
.THURSDAY NIGHT...North winds less than 10 knots. Waves calm to
2 feet.
.FRIDAY...Northeast winds 5 to 15 knots veering east by mid
afternoon. Waves calm to 2 feet.
.FRIDAY NIGHT...Southeast winds 5 to 15 knots. Waves calm to
2 feet.
.SATURDAY...Southeast winds 10 to 20 knots. A chance of showers.
Waves building to 1 to 3 feet, then subsiding to calm to 2 feet.
.SUNDAY...Northwest winds 5 to 15 knots backing west. Waves calm
to 2 feet.

$$

LSZ265-120800-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
401 PM EDT Tue Aug 11 2026

.LATE THIS AFTERNOON...East winds 5 to 15 knots. Waves calm to
2 feet.
.TONIGHT...Southeast winds 5 to 15 knots veering southwest late.
Waves calm to 2 feet.
.WEDNESDAY...West winds 5 to 15 knots veering northeast in the
afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...East winds 5 to 15 knots veering west after
midnight. A slight chance of showers after midnight. Waves calm
to 2 feet.
.THURSDAY...North winds 5 to 15 knots. 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 becoming east 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.FRIDAY NIGHT...Southeast winds 5 to 15 knots increasing to 10 to
20 knots after midnight. Waves calm to 2 feet.
.SATURDAY...Southeast winds 15 to 25 knots veering south. A
chance of showers, then showers likely. Waves building to 2 to
4 feet, then subsiding to calm to 2 feet.
.SUNDAY...Northwest winds 10 to 20 knots backing west. Waves calm
to 2 feet.

$$

LSZ266-120800-
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 PM EDT Tue Aug 11 2026

.LATE THIS AFTERNOON...Northeast winds 5 to 15 knots. Waves calm
to 2 feet.
.TONIGHT...Southwest winds 5 to 15 knots backing south late.
Waves calm to 2 feet.
.WEDNESDAY...South winds 5 to 15 knots veering west in the
afternoon, then veering 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...North winds 5 to 15 knots. Waves calm to
2 feet.
.FRIDAY...North winds 5 to 15 knots veering northeast by mid
afternoon. Waves calm to 2 feet.
.FRIDAY NIGHT...East winds 5 to 15 knots veering southeast after
midnight. Waves calm to 2 feet.
.SATURDAY...Southeast winds 15 to 25 knots veering south. A
chance of showers, then showers likely. Waves building to 1 to
3 feet, then subsiding to calm to 2 feet.
.SUNDAY...Northwest winds 10 to 20 knots. Waves calm to 2 feet.

$$

LSZ267-120800-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
401 PM EDT Tue Aug 11 2026

.LATE THIS AFTERNOON...Northwest winds 5 to 15 knots. Waves calm
to 2 feet.
.TONIGHT...Northwest winds 5 to 15 knots becoming west less than
10 knots after midnight. Waves calm to 2 feet.
.WEDNESDAY...South 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...North winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. Waves calm to 2 feet.
.FRIDAY...North winds 5 to 15 knots backing northwest by mid
afternoon. Waves calm to 2 feet.
.FRIDAY NIGHT...North winds 5 to 15 knots veering southeast after
midnight. Waves calm to 2 feet.
.SATURDAY...Southeast winds 10 to 20 knots. A chance of showers.
Waves calm to 2 feet.
.SUNDAY...Northwest winds 10 to 20 knots. Waves calm to 2 feet.

$$

LSZ261-120200-
MAFOR 1121/
Superior West 11400 12200 13700 11600 11500. Waves 1 foot or
less.

Superior North Central 11400 14500 12600 11700. Waves 1 foot or
less.

Superior South Central 11200 11300 12400 12500 11600 11800. Waves
1 foot or less.

Superior East 12700 13600 11500 11400 11500. 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