813
FZUS63 KMQT 220201
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1001 PM EDT Tue Jul 21 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...

Heights continue to rise over the lake tonight as a 29.3 inch low
pressure east of James Bay continues to track through northern
Quebec and ridging over the Northern Plains expands eastward. The
ridge over Lake Superior becomes maximized at 30.1 inches over the
western lake on Wednesday before the high flattens and moves east
towards New England Thursday into Friday morning. While ridging of
around 30.0 inches looks to remain over Lake Superior on Thursday, a
weak 29.9 to 30.0 inch low could move over the northwestern half of
the lake by Thursday night into Friday morning. As a low around 29.3
inches lifts from far northern Ontario into Hudson Bay Friday night
into Saturday morning, expect troughing of around 29.8 inches to
move into Lake Superior in response by Saturday morning. Troughing
of at least 29.8 inches looks to remain over the lake for the rest
of the day.



LSZ162-220800-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1001 PM EDT Tue Jul 21 2026 /901 PM CDT Tue Jul 21 2026/

.REST OF TONIGHT...Northwest winds 10 to 20 knots. Waves calm to
2 feet.
.WEDNESDAY...West winds 5 to 15 knots backing southwest in the
afternoon, then increasing to 10 to 20 knots late. Waves building
to 1 to 3 feet.
.WEDNESDAY NIGHT...Southwest winds 5 to 15 knots. Waves subsiding
to calm to 2 feet.
.THURSDAY...Southwest winds 10 to 20 knots. Waves building to
1 to 3 feet.
.THURSDAY NIGHT...Southwest winds 10 to 20 knots. A slight chance
of thunderstorms through midnight. A slight chance of showers.
Waves subsiding to calm to 2 feet.
.FRIDAY...Southwest winds 15 to 25 knots increasing to 20 to
30 knots by mid afternoon. Waves building to 3 to 5 feet
occasionally to 7 feet, then subsiding to 2 to 4 feet.
.FRIDAY NIGHT...Southwest winds 20 to 30 knots increasing to
gales to 35 knots after midnight. A chance of showers. Waves
building to 3 to 6 feet occasionally to 8 feet.
.SATURDAY...Southwest winds 20 to 30 knots becoming north 5 to
15 knots. A chance of showers. Waves subsiding to calm to 2 feet.
.SUNDAY...East winds 5 to 15 knots backing northeast. Waves calm
to 2 feet.

$$

LSZ263-220800-
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 Tue Jul 21 2026

.REST OF TONIGHT...Northwest winds 5 to 15 knots. Waves calm to
2 feet.
.WEDNESDAY...Northwest winds 5 to 15 knots backing west in the
afternoon, then becoming southwest 10 to 20 knots late. Waves
building to 1 to 3 feet.
.WEDNESDAY NIGHT...Southwest winds 10 to 20 knots becoming west
5 to 15 knots after midnight, then increasing to 10 to 20 knots
late. Waves subsiding to calm to 2 feet, then building to 1 to
3 feet.
.THURSDAY...Southwest winds 15 to 25 knots. Waves building to
2 to 4 feet.
.THURSDAY NIGHT...Southwest winds 10 to 20 knots increasing to
15 to 25 knots after midnight. A slight chance of showers and
thunderstorms. Waves subsiding to calm to 2 feet, then building
to 2 to 4 feet.
.FRIDAY...Southwest winds 20 to 30 knots. Waves building to 3 to
6 feet occasionally to 8 feet.
.FRIDAY NIGHT...Southwest winds 20 to 30 knots increasing to
gales to 35 knots after midnight. A chance of showers after
midnight. Waves subsiding to 2 to 4 feet, then building to 4 to
7 feet occasionally to 9 feet.
.SATURDAY...Southwest gales to 35 knots becoming north 5 to
15 knots. A chance of showers. Waves subsiding to calm to 2 feet.
.SUNDAY...East winds 5 to 15 knots. A chance of showers. Waves
calm to 2 feet.

$$

LSZ264-220800-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
1001 PM EDT Tue Jul 21 2026

.REST OF TONIGHT...Northwest winds 10 to 20 knots. Waves 2 to
4 feet subsiding to 1 to 3 feet.
.WEDNESDAY...Northwest winds 5 to 15 knots backing west in the
afternoon, then increasing to 10 to 20 knots late. Waves
subsiding to calm to 2 feet.
.WEDNESDAY NIGHT...West winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. Waves building to 1 to 3 feet.
.THURSDAY...Southwest winds 10 to 20 knots. Waves building to
2 to 4 feet.
.THURSDAY NIGHT...Southwest winds 10 to 20 knots increasing to
15 to 25 knots after midnight. A chance of showers and a slight
chance of thunderstorms. Waves subsiding to calm to 2 feet, then
building to 2 to 4 feet.
.FRIDAY...Southwest winds 15 to 25 knots. Waves building to 3 to
6 feet occasionally to 8 feet.
.FRIDAY NIGHT...South winds 20 to 30 knots veering southwest
after midnight. A chance of showers. Waves subsiding to 2 to
4 feet, then building to 4 to 7 feet occasionally to 9 feet.
.SATURDAY...Southwest winds 20 to 30 knots becoming north 5 to
15 knots. A chance of showers. Waves subsiding to calm to 2 feet.
.SUNDAY...Southeast winds 5 to 15 knots backing east. Waves calm
to 2 feet.

$$

LSZ265-220800-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1001 PM EDT Tue Jul 21 2026

.REST OF TONIGHT...Northwest winds 20 to 30 knots diminishing to
15 to 25 knots late. Waves 3 to 6 feet occasionally to 8 feet
subsiding to 2 to 4 feet.
.WEDNESDAY...Northwest winds 15 to 25 knots becoming west 10 to
20 knots late. Waves subsiding to calm to 2 feet.
.WEDNESDAY NIGHT...West winds 10 to 20 knots increasing to 15 to
25 knots late. Waves calm to 2 feet.
.THURSDAY...West winds 10 to 20 knots backing southwest by mid
afternoon. Waves building to 1 to 3 feet, then subsiding to calm
to 2 feet.
.THURSDAY NIGHT...South winds 10 to 20 knots becoming southwest
15 to 25 knots after midnight. A slight chance of showers and
thunderstorms after midnight. Waves building to 1 to 3 feet.
.FRIDAY...Southwest winds 10 to 20 knots backing south by mid
afternoon. Waves subsiding to calm to 2 feet.
.FRIDAY NIGHT...South winds 15 to 25 knots becoming southwest
20 to 30 knots after midnight. A chance of showers after
midnight. Waves building to 2 to 4 feet.
.SATURDAY...Southwest winds 15 to 25 knots becoming south 10 to
20 knots. A chance of showers. Waves subsiding to calm to 2 feet.
.SUNDAY...East winds 10 to 20 knots. A chance of showers. Waves
calm to 2 feet.

$$

LSZ266-220800-
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 Tue Jul 21 2026

.REST OF TONIGHT...Northwest winds 20 to 30 knots. Waves 4 to
7 feet occasionally to 9 feet subsiding to 3 to 5 feet
occasionally to 7 feet.
.WEDNESDAY...Northwest winds 15 to 25 knots backing west late.
Waves subsiding to 2 to 4 feet.
.WEDNESDAY NIGHT...West winds 10 to 20 knots. Waves subsiding to
1 to 3 feet.
.THURSDAY...West winds 10 to 20 knots backing southwest by mid
afternoon. Waves building to 2 to 4 feet, then subsiding to 1 to
3 feet.
.THURSDAY NIGHT...South winds 10 to 20 knots becoming southwest
15 to 25 knots after midnight. A chance of showers. A slight
chance of thunderstorms after midnight. Waves subsiding to calm
to 2 feet, then building to 1 to 3 feet.
.FRIDAY...Southwest winds 10 to 20 knots backing south by mid
afternoon. Waves building to 2 to 4 feet.
.FRIDAY NIGHT...South winds 20 to 30 knots. A chance of showers
after midnight. Waves building to 3 to 6 feet occasionally to
8 feet.
.SATURDAY...South winds 15 to 25 knots becoming southwest 5 to
15 knots. Showers likely. A chance of thunderstorms. A chance of
showers. Waves subsiding to calm to 2 feet.
.SUNDAY...North winds 5 to 15 knots veering southeast. Waves calm
to 2 feet.

$$

LSZ267-220800-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1001 PM EDT Tue Jul 21 2026

.REST OF TONIGHT...Northwest winds 20 to 30 knots. Waves 5 to
8 feet occasionally to 10 feet subsiding to 3 to 6 feet
occasionally to 8 feet.
.WEDNESDAY...Northwest winds 20 to 30 knots becoming west 15 to
25 knots late. Waves subsiding to 3 to 5 feet occasionally to
7 feet.
.WEDNESDAY NIGHT...West winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. Waves subsiding to 1 to 3 feet.
.THURSDAY...Southwest winds 5 to 15 knots. Waves subsiding to
calm to 2 feet.
.THURSDAY NIGHT...South winds 10 to 20 knots increasing to 15 to
25 knots after midnight. A slight chance of showers after
midnight. Waves building to 1 to 3 feet.
.FRIDAY...Southwest winds 5 to 15 knots backing south by mid
afternoon. Waves subsiding to calm to 2 feet.
.FRIDAY NIGHT...South winds 15 to 25 knots increasing to 20 to
30 knots after midnight. Waves building to 3 to 5 feet
occasionally to 7 feet.
.SATURDAY...South winds 15 to 25 knots becoming southwest 10 to
20 knots. A chance of showers. Waves subsiding to calm to 2 feet.
.SUNDAY...Northwest winds 10 to 20 knots becoming southeast 5 to
15 knots. Waves calm to 2 feet.

$$

LSZ261-220800-
MAFOR 2203/
Superior West 14710 11610 13520. Waves 2 feet or less.

Superior North Central 14720 11720 13620. Waves 2 to 4 feet
overnight. Waves 1 to 3 feet Wednesday and Wednesday evening.

Superior South Central 14730 12720 12610. Waves 3 to 6 feet
overnight. Waves 2 to 4 feet subsiding to 1 to 3 feet Wednesday.
Waves 1 to 2 feet Wednesday evening.

Superior East 15730 12630. Waves 4 to 7 feet subsiding to 3 to 5
feet overnight. Waves 3 to 5 feet Wednesday and Wednesday
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