891
FZUS63 KMQT 310801
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
400 AM EDT Mon Aug 31 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 29.4 inch low over Southern Saskatchewan will weaken to 29.6
inches as it moves to east-central Manitoba late tonight. This will
bring a weak, broad 29.9 inch trough over the Upper Great Lakes.
Weak troughing remains over the lake until ridging of around 29.9
inches builds over the lake on Wednesday and strengthens to 30.0
inches through Friday. Ridging will continue to build into the early
weekend, reaching 30.1 inches.



LSZ162-312000-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
401 AM EDT Mon Aug 31 2026 /301 AM CDT Mon Aug 31 2026/

.EARLY THIS MORNING...East winds 10 to 20 knots. Patchy fog. A
chance of showers and thunderstorms. Waves 2 to 4 feet subsiding
to 1 to 3 feet.
.TODAY...East winds 5 to 15 knots backing northeast in the
afternoon, then backing west late. Patchy fog through early
afternoon. A slight chance of showers and thunderstorms through
early afternoon. Waves subsiding to calm to 2 feet.
.TONIGHT...West winds 5 to 15 knots backing southwest after
midnight. Waves calm to 2 feet.
.TUESDAY...Southwest winds 10 to 20 knots increasing to 15 to
25 knots in the afternoon, then veering west late. Waves building
to 2 to 4 feet, then subsiding to 1 to 3 feet.
.TUESDAY NIGHT...West winds 5 to 15 knots. Waves subsiding to
calm to 2 feet.
.WEDNESDAY...West winds 5 to 15 knots backing south by mid
afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...Northeast winds 5 to 15 knots. Waves calm to
2 feet.
.THURSDAY...Northeast winds 15 to 25 knots diminishing to 10 to
20 knots. Waves building to 1 to 3 feet, then subsiding to calm
to 2 feet.
.FRIDAY...Northeast winds 15 to 25 knots diminishing to 10 to
20 knots. Waves calm to 2 feet.

$$

LSZ263-312000-
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 Mon Aug 31 2026

.EARLY THIS MORNING...East winds 10 to 20 knots. Patchy fog.
Showers likely and a chance of thunderstorms. Waves 1 to 3 feet.
.TODAY...Southeast winds 10 to 20 knots becoming east 5 to
15 knots in the afternoon, then veering west late. Patchy fog. A
chance of showers and a slight chance of thunderstorms. Waves
1 to 3 feet.
.TONIGHT...West winds 5 to 15 knots backing southwest after
midnight. Patchy fog. Waves subsiding to calm to 2 feet.
.TUESDAY...Southwest winds 10 to 20 knots increasing to 15 to
25 knots in the afternoon, then veering west late. Waves building
to 2 to 4 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. Waves subsiding to calm to 2 feet.
.WEDNESDAY...West winds 5 to 15 knots backing southwest by mid
afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...East winds less than 10 knots. Waves calm to
2 feet.
.THURSDAY...East winds 10 to 20 knots. Waves calm to 2 feet.
.FRIDAY...East winds 10 to 20 knots. Waves calm to 2 feet.

$$

LSZ264-312000-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
401 AM EDT Mon Aug 31 2026

.EARLY THIS MORNING...Southeast winds 10 to 20 knots. Patchy fog.
Showers likely and a slight chance of thunderstorms. Waves 1 to
3 feet.
.TODAY...Southeast winds 10 to 20 knots diminishing to 5 to
15 knots late. Patchy fog. A chance of showers. A slight chance
of thunderstorms by mid afternoon. Waves building to 2 to 4 feet,
then subsiding to 1 to 3 feet.
.TONIGHT...West winds 5 to 15 knots backing southwest late.
Patchy fog. Waves subsiding to calm to 2 feet.
.TUESDAY...Southwest winds 5 to 15 knots increasing to 15 to
25 knots. Patchy fog through early afternoon. Waves building to
2 to 4 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. Waves subsiding to calm to 2 feet.
.WEDNESDAY...Northwest winds 5 to 15 knots becoming west less
than 10 knots by mid afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...West winds less than 10 knots veering north
after midnight. Waves calm to 2 feet.
.THURSDAY...East winds 5 to 15 knots. Waves calm to 2 feet.
.FRIDAY...East winds 10 to 20 knots. Waves calm to 2 feet.

$$

LSZ265-312000-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
401 AM EDT Mon Aug 31 2026

.EARLY THIS MORNING...Southeast winds 15 to 25 knots. Patchy fog.
Showers likely and a slight chance of thunderstorms. Waves 1 to
3 feet.
.TODAY...Southeast winds 15 to 25 knots diminishing to 10 to
20 knots in the afternoon, then backing east late. Patchy fog
through early afternoon. A chance of showers. A slight chance of
thunderstorms by mid afternoon. Waves subsiding to calm to
2 feet.
.TONIGHT...West winds 10 to 20 knots backing southwest late.
Patchy fog. Waves calm to 2 feet.
.TUESDAY...South winds 10 to 20 knots veering west late. Patchy
fog through early afternoon. Waves building to 1 to 3 feet.
.TUESDAY NIGHT...West winds 15 to 25 knots diminishing to 10 to
20 knots after midnight. Waves subsiding to calm to 2 feet.
.WEDNESDAY...West winds 5 to 15 knots veering north by mid
afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...Northwest winds 5 to 15 knots. Waves calm to
2 feet.
.THURSDAY...East winds 5 to 15 knots veering southeast. Waves
calm to 2 feet.
.FRIDAY...East winds 10 to 20 knots veering southeast. Waves calm
to 2 feet.

$$

LSZ266-312000-
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 Mon Aug 31 2026

.EARLY THIS MORNING...Southeast winds 10 to 20 knots. Patchy fog.
Showers likely and a slight chance of thunderstorms. Waves calm
to 2 feet building to 1 to 3 feet.
.TODAY...Southeast winds 10 to 20 knots. Patchy fog. A chance of
showers and a slight chance of thunderstorms. Waves building to
2 to 4 feet, then subsiding to 1 to 3 feet.
.TONIGHT...Southeast winds 10 to 20 knots veering west after
midnight, then diminishing to 5 to 15 knots late. A slight chance
of showers and thunderstorms through midnight. Patchy fog through
midnight, then areas of dense fog after midnight. Waves subsiding
to calm to 2 feet.
.TUESDAY...South winds 5 to 15 knots increasing to 10 to 20 knots
in the afternoon, then veering southwest late. Patchy dense fog
through early afternoon. Waves building to 1 to 3 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots. Waves subsiding to
calm to 2 feet.
.WEDNESDAY...West winds 5 to 15 knots veering northwest by mid
afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...Northwest winds 5 to 15 knots. Waves calm to
2 feet.
.THURSDAY...North winds 5 to 15 knots veering east. Waves calm to
2 feet.
.FRIDAY...East winds 5 to 15 knots veering southeast. Waves calm
to 2 feet.

$$

LSZ267-312000-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
401 AM EDT Mon Aug 31 2026

.EARLY THIS MORNING...East winds 10 to 20 knots. Patchy fog. A
chance of showers and a slight chance of thunderstorms. Waves
calm to 2 feet building to 1 to 3 feet.
.TODAY...Southeast winds 15 to 25 knots diminishing to 10 to
20 knots late. Patchy fog. A chance of showers and a slight
chance of thunderstorms. Waves building to 2 to 4 feet, then
subsiding to 1 to 3 feet.
.TONIGHT...Southeast winds 10 to 20 knots veering west after
midnight, then diminishing to 5 to 15 knots late. A slight chance
of showers and thunderstorms through midnight. Patchy fog through
midnight, then areas of dense fog after midnight. Waves subsiding
to calm to 2 feet.
.TUESDAY...Southwest winds 5 to 15 knots backing south in the
afternoon, then increasing to 10 to 20 knots late. Widespread
dense fog through early afternoon. Waves calm to 2 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots. A slight chance of
showers through midnight. Waves calm to 2 feet.
.WEDNESDAY...West winds 10 to 20 knots diminishing to 5 to
15 knots by mid afternoon. 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 veering north. Waves
calm to 2 feet.
.FRIDAY...East winds 5 to 15 knots. Waves calm to 2 feet.

$$

LSZ261-311400-
MAFOR 3109/
Superior West 11220 11310 11300 11700 12610 11600 11500. A chance
of showers and thunderstorms this morning. Waves 2 to 4 feet
subsiding to 1 to 3 feet today. Waves 1 foot or less tonight.

Superior North Central 12326 11320 11310 11300 11500 11604 11600.
Waves 2 to 4 feet today. Waves 1 to 3 feet tonight.

Superior South Central 11326 13320 11310 13610. Waves 1 to 3
feet.

Superior East 11220 11326 19324 12320 12310 11514 11604. Waves 2
to 4 feet today. Waves 1 to 3 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