030
FZUS63 KMQT 120801
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
401 AM EDT Wed Aug 12 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, 29.5 inch low pressure is over the Gulf of St Lawrence
and deepens to 29.5 inches while a Plains low of 29.7 inches is only
separated from the first low by weak 29.8-29.9 inch ridging over
Lake Superior. 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 Lower 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.



LSZ162-122000-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
401 AM EDT Wed Aug 12 2026 /301 AM CDT Wed Aug 12 2026/

.EARLY THIS MORNING...North winds less than 10 knots. Patchy fog.
Waves calm to 2 feet.
.TODAY...Northwest winds less than 10 knots becoming south 5 to
15 knots in the afternoon. Patchy dense fog through early
afternoon. Waves calm to 2 feet.
.TONIGHT...Northeast winds 5 to 15 knots backing north after
midnight, then veering northeast late. A chance of showers. Waves
calm to 2 feet.
.THURSDAY...Northeast winds 5 to 15 knots veering east late.
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 2 to 4 feet, then
subsiding to 1 to 3 feet.
.FRIDAY NIGHT...Northeast winds 15 to 25 knots diminishing to
5 to 15 knots after midnight. Waves subsiding to calm to 2 feet.
.SATURDAY...Northeast winds 5 to 15 knots backing north. A chance
of showers. Waves calm to 2 feet.
.SUNDAY...West winds 5 to 15 knots veering northwest. Waves calm
to 2 feet.

$$

LSZ263-122000-
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 Wed Aug 12 2026

.EARLY THIS MORNING...Northwest winds less than 10 knots. Waves
calm to 2 feet.
.TODAY...Northwest winds less than 10 knots increasing to 5 to
15 knots in the afternoon, then backing south late. Waves calm to
2 feet.
.TONIGHT...East winds less than 10 knots backing north after
midnight, then veering northeast late. A slight chance of showers
after midnight. Waves calm to 2 feet.
.THURSDAY...Northeast winds less than 10 knots increasing to 5 to
15 knots in the afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...Northeast winds less than 10 knots increasing
to 5 to 15 knots after midnight. Waves calm to 2 feet.
.FRIDAY...Northeast 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 diminishing to 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.

$$

LSZ264-122000-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
401 AM EDT Wed Aug 12 2026

.EARLY THIS MORNING...West winds less than 10 knots. Waves calm
to 2 feet.
.TODAY...West winds less than 10 knots veering northwest in the
afternoon, then backing southwest late. Waves calm to 2 feet.
.TONIGHT...Southwest winds less than 10 knots veering northwest
late. Waves calm to 2 feet.
.THURSDAY...North winds less than 10 knots veering northeast in
the afternoon, then veering southwest late. Waves calm to 2 feet.
.THURSDAY NIGHT...North winds less than 10 knots increasing to
5 to 15 knots after midnight. 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 becoming northwest
5 to 15 knots. A chance of showers. Waves calm to 2 feet.
.SUNDAY...Northwest winds 5 to 15 knots backing west. Waves calm
to 2 feet.

$$

LSZ265-122000-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
401 AM EDT Wed Aug 12 2026

.EARLY THIS MORNING...West winds 5 to 15 knots. Waves calm to
2 feet.
.TODAY...West winds 5 to 15 knots veering northeast in the
afternoon, then veering east late. Waves calm to 2 feet.
.TONIGHT...Southeast winds 5 to 15 knots backing north late. A
slight chance of showers after midnight. Waves calm to 2 feet.
.THURSDAY...North winds 5 to 15 knots veering east late. A slight
chance of showers through early 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. Waves calm to 2 feet.
.FRIDAY NIGHT...Southeast winds 5 to 15 knots. Waves calm to
2 feet.
.SATURDAY...Southeast winds 15 to 25 knots diminishing to 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 15 to 25 knots becoming west 10 to
20 knots. Waves building to 1 to 3 feet, then subsiding to calm
to 2 feet.

$$

LSZ266-122000-
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 Wed Aug 12 2026

.EARLY THIS MORNING...West winds 5 to 15 knots. Waves calm to
2 feet.
.TODAY...West winds 5 to 15 knots veering north late. Waves calm
to 2 feet.
.TONIGHT...West winds 5 to 15 knots veering northwest late. Waves
calm to 2 feet.
.THURSDAY...Northwest winds 5 to 15 knots veering north in the
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 backing north 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 becoming south 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 15 to 25 knots diminishing to 10 to
20 knots. Waves building to 2 to 4 feet, then subsiding to calm
to 2 feet.

$$

LSZ267-122000-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
401 AM EDT Wed Aug 12 2026

.EARLY THIS MORNING...Northwest winds less than 10 knots. Waves
calm to 2 feet.
.TODAY...Northwest winds 5 to 15 knots. Waves calm to 2 feet.
.TONIGHT...Northwest winds 5 to 15 knots backing west late. 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. 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. Showers likely. Waves
calm to 2 feet.
.SUNDAY...Northwest winds 10 to 20 knots diminishing to 5 to
15 knots. Waves building to 1 to 3 feet, then subsiding to calm
to 2 feet.

$$

LSZ261-121400-
MAFOR 1209/
Superior West 12700 11600 12400 11200 11100 11800. A chance of
showers overnight. Waves 1 foot or less.

Superior North Central 12600 12700 12500 11600 11700. Waves 1
foot or less.

Superior South Central 11700 11600 11700 11100 11200 11300 12400.
Waves 1 foot or less.

Superior East 15700 11700 11600. 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