815
FZUS63 KMQT 071942
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
342 PM EDT Mon Apr 7 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 29.6 inch low over Georgian Bay this afternoon
continues pushing east this evening as a 30.4 inch high pressure
over northern Manitoba slides into northern Ontario by this
evening as it weakens to 30.3 inches. This high moves into the
Upper Great Lakes on Tuesday morning at 30.2 inches. Ridging of
around 30.1 inches remains over Lake Superior Wednesday and
Thursday while a 29.8 inch low moves into the Ohio River Valley.
Ridging builds to 30.3 inches Friday as high pressure from the
Plains moves in. The ridging weakens to 30.2 inches by Saturday as
29.7 inch troughing pushes in from the west.

LSZ162-080345-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
342 PM EDT Mon Apr 7 2025 /242 PM CDT Mon Apr 7 2025/

.LATE THIS AFTERNOON...North winds 10 to 20 knots. Waves 2 to
4 feet subsiding to 1 to 3 feet.
.TONIGHT...North winds 10 to 20 knots diminishing to 5 to
15 knots late. Waves subsiding to calm to 2 feet.
.TUESDAY...North winds 5 to 15 knots veering southeast in the
afternoon, then veering south late. Waves calm to 2 feet.
.TUESDAY NIGHT...Southeast winds 10 to 20 knots diminishing to
5 to 15 knots after midnight, then becoming east 10 to 20 knots
late. Waves calm to 2 feet.
.WEDNESDAY...East winds 10 to 20 knots. A chance of snow showers.
A chance of rain showers by mid afternoon. Waves building to 1 to
3 feet.
.WEDNESDAY NIGHT...East winds 10 to 20 knots backing northeast
after midnight. A chance of rain showers, possibly mixed with
snow. Waves subsiding to calm to 2 feet.
.THURSDAY...Northeast winds 10 to 20 knots diminishing to 5 to
15 knots by mid afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...Northeast winds 5 to 15 knots backing west
after midnight. Waves calm to 2 feet.
.FRIDAY...West winds 5 to 15 knots backing southwest. Waves calm
to 2 feet.
.SATURDAY...South winds 5 to 15 knots backing east. Waves calm to
2 feet.

$$

LSZ263-080345-
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-
342 PM EDT Mon Apr 7 2025

.LATE THIS AFTERNOON...North winds 15 to 25 knots. Waves 3 to
5 feet occasionally to 7 feet subsiding to 2 to 4 feet.
.TONIGHT...North winds 10 to 20 knots diminishing to 5 to
15 knots late. Isolated snow showers. Waves subsiding to 1 to
3 feet, then building to 2 to 4 feet.
.TUESDAY...North winds 5 to 15 knots veering south late. Waves
subsiding to calm to 2 feet.
.TUESDAY NIGHT...Southeast winds 5 to 15 knots. Waves calm to
2 feet.
.WEDNESDAY...Southeast winds 5 to 15 knots backing east by mid
afternoon. A slight chance of rain and snow showers. Waves calm
to 2 feet.
.WEDNESDAY NIGHT...East winds 5 to 15 knots. Waves calm to
2 feet.
.THURSDAY...East winds 5 to 15 knots backing northeast by mid
afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...North winds 5 to 15 knots becoming west less
than 10 knots after midnight. Waves calm to 2 feet.
.FRIDAY...West winds 5 to 15 knots backing southwest. Waves calm
to 2 feet.
.SATURDAY...South winds 5 to 15 knots. Waves calm to 2 feet.

$$

LSZ264-080345-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
342 PM EDT Mon Apr 7 2025

.LATE THIS AFTERNOON...North winds 15 to 25 knots. Freezing
spray. Isolated snow showers. Waves 4 to 7 feet occasionally to
9 feet.
.TONIGHT...North winds 15 to 25 knots diminishing to 10 to
20 knots late. Freezing spray through midnight. Isolated snow
showers. Waves subsiding to 2 to 4 feet.
.TUESDAY...North winds 5 to 15 knots backing northwest late.
Waves subsiding to calm to 2 feet.
.TUESDAY NIGHT...Southwest winds 5 to 15 knots backing south
after midnight. Waves calm to 2 feet.
.WEDNESDAY...Southeast winds 5 to 15 knots. Waves calm to 2 feet.
.WEDNESDAY NIGHT...East winds 5 to 15 knots. Waves calm to
2 feet.
.THURSDAY...East winds 5 to 15 knots. Waves calm to 2 feet.
.THURSDAY NIGHT...Northwest winds 5 to 15 knots backing west
after midnight. Waves calm to 2 feet.
.FRIDAY...West winds 5 to 15 knots backing southwest. Waves calm
to 2 feet.
.SATURDAY...South winds 5 to 15 knots. Waves calm to 2 feet.

$$

LSZ265-080345-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
342 PM EDT Mon Apr 7 2025

.LATE THIS AFTERNOON...North winds 20 to 30 knots. Freezing
spray. Isolated snow showers. Waves 5 to 9 feet occasionally to
11 feet.
.TONIGHT...North winds 20 to 30 knots diminishing to 15 to
25 knots after midnight. Freezing spray through midnight.
Isolated snow showers. Waves subsiding to 3 to 5 feet
occasionally to 7 feet.
.TUESDAY...North winds 15 to 25 knots diminishing to 5 to
15 knots. A slight chance of snow showers through early
afternoon. Waves subsiding to calm to 2 feet.
.TUESDAY NIGHT...Northwest winds 5 to 15 knots backing south
after midnight. Waves calm to 2 feet.
.WEDNESDAY...Southeast winds 10 to 20 knots backing east by mid
afternoon. A slight chance of snow showers through early
afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...Southeast winds 10 to 20 knots. Waves calm to
2 feet.
.THURSDAY...East winds 10 to 20 knots backing northeast by mid
afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...North winds 5 to 15 knots backing west after
midnight. Waves calm to 2 feet.
.FRIDAY...West winds 5 to 15 knots backing southwest. Waves calm
to 2 feet.
.SATURDAY...Southeast winds 5 to 15 knots becoming south 10 to
20 knots. Waves calm to 2 feet.

$$

LSZ266-080345-
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-
342 PM EDT Mon Apr 7 2025

.LATE THIS AFTERNOON...North winds to 30 knots with a few gale
force gusts to 35 knots possible. Freezing spray. Scattered snow
showers. Waves 8 to 11 feet occasionally to 14 feet subsiding to
7 to 10 feet occasionally to 13 feet.
.TONIGHT...North winds to 30 knots with a few gale force gusts to
35 knots possible diminishing to 15 to 25 knots. Freezing spray.
Scattered snow showers. Waves subsiding to 3 to 6 feet
occasionally to 8 feet.
.TUESDAY...North winds 15 to 25 knots diminishing to 10 to
20 knots in the afternoon, then backing northwest late. A slight
chance of snow showers through early afternoon. Waves subsiding
to 1 to 3 feet.
.TUESDAY NIGHT...Northwest winds 5 to 15 knots backing west after
midnight, then becoming south 10 to 20 knots late. Waves
subsiding to calm to 2 feet.
.WEDNESDAY...Southeast winds 10 to 20 knots backing east by mid
afternoon. A slight chance of snow showers through early
afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...Southeast winds 10 to 20 knots. Waves calm to
2 feet.
.THURSDAY...East winds 5 to 15 knots backing northeast by mid
afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...North winds 5 to 15 knots backing northwest
after midnight. Waves calm to 2 feet.
.FRIDAY...Northwest winds 5 to 15 knots backing west. Waves calm
to 2 feet.
.SATURDAY...South winds 5 to 15 knots increasing to 10 to
20 knots. Waves calm to 2 feet.

$$

LSZ267-080345-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
342 PM EDT Mon Apr 7 2025

.LATE THIS AFTERNOON...North winds to 30 knots with a few gale
force gusts to 35 knots possible. Freezing spray. Isolated snow
showers. Waves 6 to 9 feet occasionally to 11 feet.
.TONIGHT...North winds to 30 knots with a few gale force gusts to
35 knots possible diminishing to 15 to 25 knots. Freezing spray.
Isolated snow showers. Waves subsiding to 3 to 5 feet
occasionally to 7 feet.
.TUESDAY...North winds 15 to 25 knots backing northwest in the
afternoon. A slight chance of snow showers. Waves subsiding to
1 to 3 feet.
.TUESDAY NIGHT...Northwest winds 10 to 20 knots backing southwest
late. Waves subsiding to calm to 2 feet.
.WEDNESDAY...Southeast winds 10 to 20 knots backing east by mid
afternoon. A slight chance of snow showers through early
afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...Southeast winds 10 to 20 knots. Waves calm to
2 feet.
.THURSDAY...East winds 10 to 20 knots backing north by mid
afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...North winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. Waves calm to 2 feet.
.FRIDAY...Northwest winds 5 to 15 knots. Waves calm to 2 feet.
.SATURDAY...Northwest winds 5 to 15 knots becoming south 10 to
20 knots. Waves calm to 2 feet.

$$

LSZ261-080345-
MAFOR 0721/
Superior West 14820 12810 11100 11300. Waves 2 to 4 feet
subsiding to 1 to 3 feet tonight. Waves 2 feet or less Tuesday.

Superior North Central 13841 11830 12820 11810 11710. Waves 4 to
7 feet subsiding to 3 to 6 feet tonight. Waves 2 to 4 feet
subsiding to 1 to 3 feet Tuesday.

Superior South Central 11741 11841 19847 11841 11830 13820 11710.
Waves 5 to 9 feet subsiding to 3 to 6 feet tonight. Waves 3 to 5
feet subsiding to 2 to 4 feet Tuesday.

Superior East 13841 11830 13820 11720. Waves 5 to 9 feet
subsiding to 3 to 6 feet tonight. Waves 3 to 5 feet subsiding to
2 to 4 feet Tuesday.

$$

TAP

Experimental modernized open lake forecast is available online at
weather.gov/mqt/glftable

Graphical marine forecasts are available online at:
weather.gov/greatlakes