658
FZUS63 KMQT 042003
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
402 PM EDT Fri Jul 4 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...

30.0 inch ridge breaks down this evening as low pressure currently
moving into Northern Ontario sends a 29.8 inch trough over the lake.
This may deepen further to 29.7 inches Saturday afternoon. The
trough then lingers over the lake through Sunday morning, with 30.1
inch high pressure building over the Plains. This high moves over
the Great Lakes basin late Sunday, then migrates eastward Monday.
Tuesday, another high builds across Hudson Bay which will sustain
30.0 or 30.1 inch ridging through at least early Thursday.


LSZ162-050800-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
402 PM EDT Fri Jul 4 2025 /302 PM CDT Fri Jul 4 2025/

.LATE THIS AFTERNOON...Northeast winds 10 to 20 knots. Waves calm
to 2 feet.
.TONIGHT...Southwest winds 10 to 20 knots becoming south 5 to
15 knots after midnight. A chance of showers and thunderstorms.
Waves building to 1 to 3 feet, then subsiding to calm to 2 feet.
.SATURDAY...Southwest winds 5 to 15 knots increasing to 10 to
20 knots in the afternoon, then veering northwest late. Patchy
fog. Showers likely and a chance of thunderstorms. Waves calm to
2 feet.
.SATURDAY NIGHT...Northwest winds 10 to 20 knots veering north
late. A slight chance of thunderstorms through midnight. A slight
chance of showers. Waves calm to 2 feet.
.SUNDAY...Northeast winds 10 to 20 knots becoming east 5 to
15 knots by mid afternoon. Waves building to 1 to 3 feet, then
subsiding to calm to 2 feet.
.SUNDAY NIGHT...Northeast winds 5 to 15 knots. Waves calm to
2 feet.
.MONDAY...East winds 5 to 15 knots. Waves calm to 2 feet.
.MONDAY NIGHT...Northeast winds 5 to 15 knots. A chance of
showers and thunderstorms. Waves calm to 2 feet.
.TUESDAY...Northeast winds 5 to 15 knots. A chance of showers.
Waves calm to 2 feet.
.WEDNESDAY...East winds 5 to 15 knots backing northeast. Waves
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-
402 PM EDT Fri Jul 4 2025

.LATE THIS AFTERNOON...South winds 5 to 15 knots. Isolated
showers and thunderstorms. Waves calm to 2 feet.
.TONIGHT...Southwest winds 10 to 20 knots diminishing to 5 to
15 knots late. A chance of showers and thunderstorms. Waves
building to 1 to 3 feet, then subsiding to calm to 2 feet.
.SATURDAY...Southwest winds 5 to 15 knots veering north late.
Patchy fog. Showers and a chance of thunderstorms. Waves
subsiding to calm to 2 feet.
.SATURDAY NIGHT...North winds 5 to 15 knots backing northwest
after midnight, then becoming north 10 to 20 knots late. A slight
chance of thunderstorms through midnight. A chance of showers.
Waves building to 1 to 3 feet.
.SUNDAY...Northeast winds 10 to 20 knots diminishing to 5 to
15 knots by mid afternoon. Waves subsiding to calm to 2 feet.
.SUNDAY NIGHT...Northeast winds 5 to 15 knots becoming east less
than 10 knots after midnight. Waves calm to 2 feet.
.MONDAY...East winds 5 to 15 knots. Waves calm to 2 feet.
.MONDAY NIGHT...East winds 5 to 15 knots. A chance of showers.
Waves calm to 2 feet.
.TUESDAY...Northeast winds 5 to 15 knots. A chance of showers.
Waves calm to 2 feet.
.WEDNESDAY...Northeast winds 5 to 15 knots veering east. Waves
calm to 2 feet.

$$

LSZ264-050800-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
402 PM EDT Fri Jul 4 2025

.LATE THIS AFTERNOON...South winds 10 to 20 knots. Isolated
showers and thunderstorms. Waves 2 to 4 feet.
.TONIGHT...South winds 10 to 20 knots veering southwest after
midnight, then becoming south 5 to 15 knots late. A chance of
showers and a slight chance of thunderstorms. Waves subsiding to
1 to 3 feet.
.SATURDAY...Southwest winds 5 to 15 knots veering north late.
Patchy fog. A chance of showers through early afternoon. A chance
of thunderstorms. Showers likely by mid afternoon. Waves
subsiding to calm to 2 feet.
.SATURDAY NIGHT...North winds 5 to 15 knots increasing to 10 to
20 knots late. A slight chance of thunderstorms through midnight.
A chance of showers. Waves building to 2 to 4 feet.
.SUNDAY...North winds 10 to 20 knots diminishing to 5 to 15 knots
by mid afternoon. Waves subsiding to calm to 2 feet.
.SUNDAY NIGHT...Northwest winds 5 to 15 knots veering east after
midnight. Waves calm to 2 feet.
.MONDAY...East winds 5 to 15 knots veering southeast by mid
afternoon. Waves calm to 2 feet.
.MONDAY NIGHT...Southeast winds 5 to 15 knots. A chance of
showers. Waves calm to 2 feet.
.TUESDAY...East winds 5 to 15 knots backing northeast. Waves calm
to 2 feet.
.WEDNESDAY...Northeast winds 5 to 15 knots veering east. Waves
calm to 2 feet.

$$

LSZ265-050800-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
402 PM EDT Fri Jul 4 2025

.LATE THIS AFTERNOON...South winds 10 to 20 knots. Isolated
showers and thunderstorms. Waves 1 to 3 feet building to 2 to
4 feet.
.TONIGHT...South winds 10 to 20 knots veering southwest after
midnight. Waves subsiding to calm to 2 feet.
.SATURDAY...South winds 10 to 20 knots becoming west 5 to
15 knots late. A chance of showers through early afternoon. A
chance of thunderstorms. Showers likely by mid afternoon. Patchy
fog by mid afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...Northwest winds 10 to 20 knots becoming north
15 to 25 knots late. Showers likely and a chance of thunderstorms
through midnight, then a chance of showers after midnight. Waves
building to 1 to 3 feet.
.SUNDAY...North winds 15 to 25 knots diminishing to 10 to
20 knots by mid afternoon. A slight chance of showers through
early afternoon. Waves building to 2 to 4 feet, then subsiding to
1 to 3 feet.
.SUNDAY NIGHT...Northwest winds 10 to 20 knots becoming north
5 to 15 knots after midnight. Waves subsiding to calm to 2 feet.
.MONDAY...East winds 5 to 15 knots. Waves calm to 2 feet.
.MONDAY NIGHT...Southeast winds 5 to 15 knots veering south after
midnight. A chance of showers after midnight. Waves calm to
2 feet.
.TUESDAY...East winds 5 to 15 knots backing north. Waves calm to
2 feet.
.WEDNESDAY...Northeast winds 5 to 15 knots veering east. Waves
calm to 2 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-
402 PM EDT Fri Jul 4 2025

.LATE THIS AFTERNOON...South winds 15 to 25 knots. Isolated
showers and thunderstorms. Waves 2 to 4 feet.
.TONIGHT...South winds 15 to 25 knots diminishing to 10 to
20 knots late. Isolated showers and thunderstorms through
midnight. Waves building to 3 to 5 feet occasionally to 7 feet,
then subsiding to 2 to 4 feet.
.SATURDAY...South winds 10 to 20 knots. A chance of showers
through early afternoon. A chance of thunderstorms. Showers
likely by mid afternoon. Patchy fog by mid afternoon. Waves
subsiding to calm to 2 feet.
.SATURDAY NIGHT...Northwest winds 10 to 20 knots becoming north
15 to 25 knots late. Showers through midnight. A chance of
thunderstorms. A chance of showers after midnight. Waves building
to 2 to 4 feet.
.SUNDAY...North winds 15 to 25 knots. A slight chance of showers
through early afternoon. Waves 2 to 4 feet.
.SUNDAY NIGHT...North winds 10 to 20 knots. Waves subsiding to
calm to 2 feet.
.MONDAY...Northeast winds 10 to 20 knots becoming east 5 to
15 knots by mid afternoon. Waves calm to 2 feet.
.MONDAY NIGHT...Southeast winds 5 to 15 knots veering south after
midnight. Waves calm to 2 feet.
.TUESDAY...Southeast winds 5 to 15 knots backing northeast. Waves
calm to 2 feet.
.WEDNESDAY...North winds 5 to 15 knots. Waves calm to 2 feet.

$$

LSZ267-050800-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
402 PM EDT Fri Jul 4 2025

.LATE THIS AFTERNOON...South winds 15 to 25 knots. Waves 1 to
3 feet.
.TONIGHT...South winds 15 to 25 knots. Isolated showers and
thunderstorms through midnight. Waves building to 2 to 4 feet.
.SATURDAY...South winds 15 to 25 knots diminishing to 10 to
20 knots in the afternoon. A chance of showers and a slight
chance of thunderstorms by mid afternoon. Waves subsiding to calm
to 2 feet.
.SATURDAY NIGHT...Southwest winds 10 to 20 knots veering
northwest after midnight, then veering north late. Showers and a
chance of thunderstorms. Waves building to 1 to 3 feet.
.SUNDAY...North winds 15 to 25 knots. A slight chance of
thunderstorms through early afternoon. A chance of showers. Waves
building to 2 to 4 feet.
.SUNDAY NIGHT...North winds 10 to 20 knots veering northeast
after midnight. Waves subsiding to calm to 2 feet.
.MONDAY...Northeast winds 10 to 20 knots backing northwest by mid
afternoon. Waves calm to 2 feet.
.MONDAY NIGHT...West winds 5 to 15 knots backing southwest after
midnight. Waves calm to 2 feet.
.TUESDAY...East winds 5 to 15 knots increasing to 10 to 20 knots.
Waves calm to 2 feet.
.WEDNESDAY...North winds 10 to 20 knots diminishing to 5 to
15 knots. Waves calm to 2 feet.

$$

LSZ261-050200-
MAFOR 0421/
Superior West 11210 12520 11420 11510 12516 11616. A chance of
thunderstorms overnight and Saturday. Waves 1 to 3 feet.

Superior North Central 12420 11510 11520 11420 12510 11406. A
chance of thunderstorms Saturday afternoon. Waves 2 to 4 feet
tonight. Waves 1 to 3 feet Saturday.

Superior South Central 13430 11520 13420 11326. A chance of
thunderstorms Saturday afternoon. Waves 2 to 4 feet subsiding to
1 to 3 feet tonight. Waves 1 to 3 feet Saturday.

Superior East 11420 13430 14420. A chance of showers Saturday
afternoon. Waves 2 to 4 feet.

$$

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