409
FZUS63 KMQT 042001
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
401 PM EDT Fri Sep 4 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...

High pressure ridging builds to 30.1 inches over Lake Superior by
Saturday afternoon, remaining through Sunday night. The ridge
briefly builds further to 30.2 inches on Monday as a 30.4 inch high
passes eastward over far northern Ontario. Meanwhile, a 29.6 inch
low develops off the northern Rockies. The low then tracks northeast
to James Bay, deepening to 29.3 inches by Wednesday afternoon. This
sends a 29.7 inch trough over Lake Superior Tuesday night and
Wednesday.



LSZ162-050800-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
401 PM EDT Fri Sep 4 2026 /301 PM CDT Fri Sep 4 2026/

.LATE THIS AFTERNOON...Northeast winds 15 to 25 knots. A slight
chance of showers. Waves 3 to 5 feet occasionally to 7 feet
subsiding to 2 to 4 feet.
.TONIGHT...Northeast winds 15 to 25 knots diminishing to 10 to
20 knots after midnight. Patchy fog after midnight. Waves
subsiding to calm to 2 feet.
.SATURDAY...Northeast winds 10 to 20 knots. Patchy fog through
early afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...Northeast winds 5 to 15 knots. Waves calm to
2 feet.
.SUNDAY...East winds 5 to 15 knots backing northeast by mid
afternoon. A slight chance of showers by mid afternoon. Waves
calm to 2 feet.
.SUNDAY NIGHT...Northeast winds 5 to 15 knots. Waves calm to
2 feet.
.MONDAY...East winds 10 to 20 knots increasing to gales to
35 knots by mid afternoon. A chance of showers. Waves building to
4 to 7 feet occasionally to 9 feet.
.MONDAY NIGHT...East gales to 35 knots becoming southeast 20 to
30 knots after midnight. Showers. Waves building to 5 to 8 feet
occasionally to 10 feet.
.TUESDAY...South winds 20 to 30 knots veering west. A chance of
showers and thunderstorms. Waves subsiding to 1 to 3 feet.
.WEDNESDAY...West gales to 40 knots becoming northwest 20 to
30 knots. Waves building to 3 to 5 feet occasionally to 7 feet,
then subsiding to calm to 2 feet.

$$

LSZ263-050800-
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 Fri Sep 4 2026

.LATE THIS AFTERNOON...Northeast winds 15 to 25 knots. A slight
chance of showers. Waves 2 to 4 feet.
.TONIGHT...Northeast winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. A slight chance of showers through
midnight. Patchy fog after midnight. Waves subsiding to calm to
2 feet.
.SATURDAY...Northeast winds 5 to 15 knots increasing to 10 to
20 knots late. Waves calm to 2 feet.
.SATURDAY NIGHT...East winds 5 to 15 knots becoming southeast
less than 10 knots late. Waves calm to 2 feet.
.SUNDAY...Southeast winds less than 10 knots becoming east 5 to
15 knots by mid afternoon. Waves calm to 2 feet.
.SUNDAY NIGHT...East winds 5 to 15 knots becoming south 10 to
20 knots after midnight. Waves calm to 2 feet.
.MONDAY...East winds 10 to 20 knots increasing to 15 to 25 knots
by mid afternoon. A chance of showers. Waves building to 3 to
6 feet occasionally to 8 feet.
.MONDAY NIGHT...East winds 20 to 30 knots becoming southeast
gales to 35 knots after midnight. A chance of showers through
midnight, then showers likely after midnight. Waves building to
4 to 7 feet occasionally to 9 feet.
.TUESDAY...South gales to 35 knots veering southwest. Showers. A
chance of showers. Waves building to 5 to 8 feet occasionally to
10 feet, then subsiding to 2 to 4 feet.
.WEDNESDAY...West gales to 40 knots veering northwest. Waves
building to 4 to 7 feet occasionally to 9 feet, then subsiding to
3 to 5 feet occasionally to 7 feet.

$$

LSZ264-050800-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
401 PM EDT Fri Sep 4 2026

.LATE THIS AFTERNOON...East winds 10 to 20 knots. A slight chance
of showers. Waves 1 to 3 feet.
.TONIGHT...Northeast winds 5 to 15 knots. Waves subsiding to calm
to 2 feet.
.SATURDAY...East winds 5 to 15 knots. Waves calm to 2 feet.
.SATURDAY NIGHT...East winds 5 to 15 knots becoming southeast
less than 10 knots after midnight. Waves calm to 2 feet.
.SUNDAY...Southeast winds less than 10 knots increasing to 5 to
15 knots by mid afternoon. Waves calm to 2 feet.
.SUNDAY NIGHT...Southeast winds 5 to 15 knots. Waves calm to
2 feet.
.MONDAY...East winds 5 to 15 knots increasing to 10 to 20 knots
by mid afternoon. Waves building to 2 to 4 feet.
.MONDAY NIGHT...East winds 15 to 25 knots becoming southeast
20 to 30 knots after midnight. A chance of showers through
midnight, then showers likely after midnight. Waves building to
4 to 7 feet occasionally to 9 feet.
.TUESDAY...South gales to 40 knots. Showers. A chance of showers.
Waves building to 8 to 11 feet occasionally to 14 feet, then
subsiding to 3 to 6 feet occasionally to 8 feet.
.WEDNESDAY...West gales to 45 knots becoming northwest gales to
40 knots. Waves building to 5 to 8 feet occasionally to 10 feet,
then subsiding to 3 to 5 feet occasionally to 7 feet.

$$

LSZ265-050800-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
401 PM EDT Fri Sep 4 2026

.LATE THIS AFTERNOON...East winds 10 to 20 knots. A slight chance
of showers. Waves 2 to 4 feet.
.TONIGHT...East winds 10 to 20 knots diminishing to 5 to 15 knots
after midnight, then backing northeast late. A slight chance of
showers. Waves subsiding to calm to 2 feet.
.SATURDAY...East winds 5 to 15 knots increasing to 10 to 20 knots
in the afternoon, then diminishing to 5 to 15 knots late. Waves
calm to 2 feet.
.SATURDAY NIGHT...East winds 5 to 15 knots veering southeast
after midnight. Waves calm to 2 feet.
.SUNDAY...Southeast winds 5 to 15 knots becoming east 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.SUNDAY NIGHT...Southeast winds 10 to 20 knots veering south
after midnight. Waves calm to 2 feet.
.MONDAY...South winds 5 to 15 knots becoming east 10 to 20 knots
by mid afternoon. Waves building to 2 to 4 feet.
.MONDAY NIGHT...Southeast winds 20 to 30 knots. A chance of
showers. Waves building to 4 to 7 feet occasionally to 9 feet.
.TUESDAY...South gales to 40 knots diminishing to 20 to 30 knots.
Showers. A chance of showers. Waves building to 7 to 10 feet
occasionally to 13 feet, then subsiding to 2 to 4 feet.
.WEDNESDAY...West gales to 45 knots becoming northwest gales to
40 knots. Waves building to 4 to 7 feet occasionally to 9 feet,
then subsiding to 3 to 6 feet occasionally to 8 feet.

$$

LSZ266-050800-
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 Fri Sep 4 2026

.LATE THIS AFTERNOON...East winds 10 to 20 knots. Waves 1 to
3 feet.
.TONIGHT...Northeast winds 10 to 20 knots diminishing to 5 to
15 knots after midnight, then veering east late. A slight chance
of showers through midnight. Waves subsiding to calm to 2 feet.
.SATURDAY...East winds 5 to 15 knots backing northeast late.
Waves calm to 2 feet.
.SATURDAY NIGHT...North winds 5 to 15 knots veering east late.
Waves calm to 2 feet.
.SUNDAY...Southeast winds 5 to 15 knots backing east by mid
afternoon. Waves calm to 2 feet.
.SUNDAY NIGHT...Southeast winds 5 to 15 knots veering south after
midnight. Waves calm to 2 feet.
.MONDAY...South winds 5 to 15 knots becoming east 10 to 20 knots
by mid afternoon. Waves building to 2 to 4 feet.
.MONDAY NIGHT...Southeast winds 15 to 25 knots increasing to
20 to 30 knots after midnight. A chance of showers. Waves
building to 4 to 7 feet occasionally to 9 feet.
.TUESDAY...South gales to 40 knots. Showers. A chance of showers.
Waves building to 8 to 11 feet occasionally to 14 feet, then
subsiding to 3 to 6 feet occasionally to 8 feet.
.WEDNESDAY...West gales to 40 knots veering northwest. Waves
building to 5 to 8 feet occasionally to 10 feet, then subsiding
to 3 to 6 feet occasionally to 8 feet.

$$

LSZ267-050800-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
401 PM EDT Fri Sep 4 2026

.LATE THIS AFTERNOON...Northeast winds 10 to 20 knots. Waves calm
to 2 feet.
.TONIGHT...Northeast winds 5 to 15 knots becoming east 10 to
20 knots after midnight. Waves calm to 2 feet.
.SATURDAY...East winds 5 to 15 knots backing north late. Waves
calm to 2 feet.
.SATURDAY NIGHT...North winds 5 to 15 knots veering northeast
after midnight, then veering southeast late. Waves calm to
2 feet.
.SUNDAY...Southeast winds 5 to 15 knots backing east by mid
afternoon. Waves calm to 2 feet.
.SUNDAY NIGHT...Southeast winds 5 to 15 knots veering south after
midnight. Waves calm to 2 feet.
.MONDAY...Southeast winds 5 to 15 knots backing east by mid
afternoon. Waves calm to 2 feet.
.MONDAY NIGHT...Southeast winds 10 to 20 knots increasing to
15 to 25 knots after midnight. A chance of showers after
midnight. Waves building to 3 to 5 feet occasionally to 7 feet.
.TUESDAY...Southeast winds 20 to 30 knots veering south. Showers.
Waves building to 4 to 7 feet occasionally to 9 feet, then
subsiding to 3 to 6 feet occasionally to 8 feet.
.WEDNESDAY...West gales to 35 knots veering northwest. Waves
building to 4 to 7 feet occasionally to 9 feet.

$$

LSZ261-050200-
MAFOR 0421/
Superior West 11140 11130 12120 14110. Waves 3 to 5 feet
subsiding to 2 to 3 feet tonight. Waves 1 to 2 feet Saturday.

Superior North Central 11220 11110 14100 12200. Waves 1 to 3
feet.

Superior South Central 11220 12210 11100 11110 13210. Waves 1 to
3 feet.

Superior East 11110 12100 13210 12100. Waves 2 feet 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