812
FZUS63 KMQT 220202
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1002 PM EDT Mon Jul 21 2025

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 30.1 inch high pressure near Sault Ste. Marie moves into the Lower
Great Lakes this evening and then into New England by Tuesday
afternoon as it builds to 30.2 inches. Low pressure pushes out of
the Rockies on Tuesday while another moves through Hudson Bay.
Between these, 29.8 to 29.9 inch troughing is expected to persist
over Lake Superior late Tuesday into Thursday night. Weak 30.0 inch
ridging builds back over the Upper Great Lakes on Friday before
weakening to 29.9 inches on Saturday.


LSZ162-220800-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1002 PM EDT Mon Jul 21 2025 /902 PM CDT Mon Jul 21 2025/

.REST OF TONIGHT...Northeast winds 10 to 20 knots diminishing to
5 to 15 knots after midnight. A slight chance of showers. Waves
calm to 2 feet.
.TUESDAY...South winds 5 to 15 knots backing east in the
afternoon, then increasing to 10 to 20 knots late. A chance of
showers. A chance of thunderstorms by mid afternoon. Waves calm
to 2 feet.
.TUESDAY NIGHT...Northeast winds 10 to 20 knots veering south
after midnight, then veering southwest late. Thunderstorms likely
through midnight. Showers likely. A chance of thunderstorms after
midnight. Waves calm to 2 feet.
.WEDNESDAY...Southwest winds 10 to 20 knots. A chance of showers
through early afternoon. A chance of thunderstorms. Showers
likely by mid afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...Southwest winds 5 to 15 knots veering
northwest after midnight. Showers likely through midnight. A
chance of thunderstorms. A chance of showers after midnight.
Waves calm to 2 feet.
.THURSDAY...West winds 5 to 15 knots backing southwest by mid
afternoon. A chance of showers. Waves calm to 2 feet.
.THURSDAY NIGHT...West winds 5 to 15 knots veering northwest
after midnight. Waves calm to 2 feet.
.FRIDAY...Southeast winds 5 to 15 knots backing east. Waves calm
to 2 feet.
.SATURDAY...East winds 5 to 15 knots veering west. 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-
1002 PM EDT Mon Jul 21 2025

.REST OF TONIGHT...Southeast winds 5 to 15 knots veering south
after midnight. A slight chance of showers. Waves calm to 2 feet.
.TUESDAY...South winds 5 to 15 knots backing east late. A chance
of showers. A slight chance of thunderstorms by mid afternoon.
Waves calm to 2 feet.
.TUESDAY NIGHT...East winds 5 to 15 knots veering south after
midnight, then veering southwest late. Showers likely and a
chance of thunderstorms. Waves calm to 2 feet.
.WEDNESDAY...Southwest winds 5 to 15 knots veering west by mid
afternoon. A chance of showers through early afternoon. A chance
of thunderstorms. Showers likely by mid afternoon. Waves calm to
2 feet.
.WEDNESDAY NIGHT...Southwest winds 5 to 15 knots veering
northwest after midnight. Showers likely through midnight. A
chance of thunderstorms. A chance of showers after midnight.
Waves calm to 2 feet.
.THURSDAY...West winds 5 to 15 knots. A chance of showers. Waves
calm to 2 feet.
.THURSDAY NIGHT...West winds 5 to 15 knots diminishing to less
than 10 knots after midnight. Waves calm to 2 feet.
.FRIDAY...South winds 5 to 15 knots becoming southeast less than
10 knots. Waves calm to 2 feet.
.SATURDAY...South winds 5 to 15 knots veering southwest. 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-
1002 PM EDT Mon Jul 21 2025

.REST OF TONIGHT...Southeast winds 5 to 15 knots veering south
late. A slight chance of showers. Waves calm to 2 feet building
to 1 to 3 feet.
.TUESDAY...South winds 5 to 15 knots backing southeast late. A
chance of showers and a slight chance of thunderstorms by mid
afternoon. Waves subsiding to calm to 2 feet.
.TUESDAY NIGHT...Southeast winds 5 to 15 knots veering south
after midnight. Showers and a chance of thunderstorms. Waves
building to 2 to 4 feet, then subsiding to 1 to 3 feet.
.WEDNESDAY...Southwest winds 5 to 15 knots. A chance of showers
and thunderstorms. Waves subsiding to calm to 2 feet.
.WEDNESDAY NIGHT...West winds 5 to 15 knots. Showers likely
through midnight. A chance of thunderstorms. A chance of showers
after midnight. Waves calm to 2 feet.
.THURSDAY...Northwest winds 5 to 15 knots backing west by mid
afternoon. A chance of showers. Waves calm to 2 feet.
.THURSDAY NIGHT...West winds less than 10 knots. Waves calm to
2 feet.
.FRIDAY...West winds less than 10 knots backing south. Waves calm
to 2 feet.
.SATURDAY...South winds 5 to 15 knots. Waves calm to 2 feet.

$$

LSZ265-220800-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1002 PM EDT Mon Jul 21 2025

.REST OF TONIGHT...Southeast winds 10 to 20 knots veering south
after midnight. Waves calm to 2 feet.
.TUESDAY...South winds 10 to 20 knots backing southeast in the
afternoon, then increasing to 15 to 25 knots late. A slight
chance of showers and thunderstorms by mid afternoon. Waves
building to 1 to 3 feet.
.TUESDAY NIGHT...South winds 15 to 25 knots diminishing to 10 to
20 knots after midnight. A chance of showers through midnight. A
chance of thunderstorms. Showers after midnight. Waves subsiding
to calm to 2 feet.
.WEDNESDAY...South winds 10 to 20 knots. A chance of showers
through early afternoon. A chance of thunderstorms. Showers
likely by mid afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...West winds 5 to 15 knots. Showers likely
through midnight. A chance of thunderstorms. A chance of showers
after midnight. Waves calm to 2 feet.
.THURSDAY...West winds 5 to 15 knots veering north by mid
afternoon. A chance of showers and thunderstorms. Waves calm to
2 feet.
.THURSDAY NIGHT...Northwest winds 5 to 15 knots backing west
after midnight. Waves calm to 2 feet.
.FRIDAY...East winds 5 to 15 knots veering southeast. Waves calm
to 2 feet.
.SATURDAY...Southeast winds 5 to 15 knots veering southwest.
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-
1002 PM EDT Mon Jul 21 2025

.REST OF TONIGHT...Southeast winds 10 to 20 knots veering south
after midnight. Waves calm to 2 feet building to 1 to 3 feet.
.TUESDAY...South winds 10 to 20 knots increasing to 15 to
25 knots late. A slight chance of showers by mid afternoon. Waves
subsiding to calm to 2 feet, then building to 1 to 3 feet.
.TUESDAY NIGHT...South winds 15 to 25 knots. A chance of showers
through midnight. A chance of thunderstorms. Showers after
midnight. Waves building to 2 to 4 feet.
.WEDNESDAY...South winds 10 to 20 knots. Showers likely and a
chance of thunderstorms. Waves subsiding to calm to 2 feet.
.WEDNESDAY NIGHT...Southwest winds 5 to 15 knots veering west
after midnight. Showers likely through midnight. A chance of
thunderstorms. A chance of showers after midnight. Waves calm to
2 feet.
.THURSDAY...West winds 5 to 15 knots veering northwest by mid
afternoon. A chance of showers and thunderstorms. Waves calm to
2 feet.
.THURSDAY NIGHT...Northwest winds 5 to 15 knots. Waves calm to
2 feet.
.FRIDAY...West winds 5 to 15 knots backing southeast. Waves calm
to 2 feet.
.SATURDAY...Southeast winds 5 to 15 knots veering south. 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-
1002 PM EDT Mon Jul 21 2025

.REST OF TONIGHT...Southeast winds 5 to 15 knots becoming south
10 to 20 knots late. Waves calm to 2 feet.
.TUESDAY...South winds 10 to 20 knots. Waves calm to 2 feet.
.TUESDAY NIGHT...South winds 15 to 25 knots. A slight chance of
showers through midnight. A chance of thunderstorms. Showers
likely after midnight. Waves building to 2 to 4 feet.
.WEDNESDAY...South winds 15 to 25 knots diminishing to 10 to
20 knots by mid afternoon. Showers likely through early
afternoon. A chance of thunderstorms. A chance of showers by mid
afternoon. Waves subsiding to calm to 2 feet.
.WEDNESDAY NIGHT...Southwest winds 10 to 20 knots veering west
after midnight. Showers likely and a chance of thunderstorms.
Waves calm to 2 feet.
.THURSDAY...Southwest winds 10 to 20 knots veering northwest by
mid afternoon. Showers likely and a chance of thunderstorms.
Waves calm to 2 feet.
.THURSDAY NIGHT...Northwest winds 5 to 15 knots. Waves calm to
2 feet.
.FRIDAY...Northwest winds 5 to 15 knots backing southeast. Waves
calm to 2 feet.
.SATURDAY...Southeast winds 5 to 15 knots veering south. Waves
calm to 2 feet.

$$

LSZ261-220800-
MAFOR 2203/
Superior West 13310 11410 12300 11210 11219. Waves 2 feet or
less.

Superior North Central 11310 14410 12310 11316. A chance of
thunderstorms Tuesday evening. Waves 1 to 3 feet.

Superior South Central 11310 14410 13320. A chance of showers and
thunderstorms Tuesday evening. Waves 1 to 3 feet.

Superior East 11300 14410 11310 12420. Waves 2 feet or less
overnight and Tuesday. Waves 2 to 3 feet Tuesday 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