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FZUS63 KMQT 031401
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1001 AM EDT Wed Sep 3 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 29.5 inch low over Lake Superior this morning lifts back into
northern Ontario today. This low then retrogrades westward over far
northern Ontario on Thursday as it deepens to 29.3 inches. While
this low remains in place Thursday night, a quick moving low
traverses through Wisconsin at 29.4 inches. This low then lifts
northeast into Ontario by Friday afternoon, then to near James Bay
Friday night while consolidating with the northern Ontario low. The
consolidated low then shifts northeast through far northern Quebec
on Saturday as 30.1 inch high pressure moves into the Midwest for
the weekend, strengthening to 30.3 inches over the Upper Mississippi
Valley on Sunday. This high brings 30.2 inch ridging over Lake
Superior Sunday night. Ridging begins to dissipate over the Upper
Great Lakes on Monday as the high continues east towards New
England.


LSZ162-032000-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1001 AM EDT Wed Sep 3 2025 /901 AM CDT Wed Sep 3 2025/

.REST OF TODAY...North winds 20 to 30 knots backing northwest
late. A slight chance of showers. A slight chance of waterspouts
by mid afternoon. Waves 3 to 6 feet occasionally to 8 feet.
.TONIGHT...Northwest winds 20 to 30 knots diminishing to 15 to
25 knots after midnight. A slight chance of waterspouts. A slight
chance of showers. Waves building to 3 to 6 feet occasionally to
8 feet.
.THURSDAY...West winds 15 to 25 knots. A slight chance of
waterspouts through early afternoon. A slight chance of showers.
Waves subsiding to 2 to 4 feet.
.THURSDAY NIGHT...West winds 10 to 20 knots veering northwest
after midnight. A slight chance of waterspouts. A chance of
showers. Waves subsiding to 1 to 3 feet, then building to 2 to
4 feet.
.FRIDAY...West winds 20 to 30 knots. A slight chance of
waterspouts. A slight chance of showers. Waves building to 3 to
6 feet occasionally to 8 feet.
.FRIDAY NIGHT...West winds 15 to 25 knots veering northwest after
midnight. Waves subsiding to 2 to 4 feet.
.SATURDAY...Northwest winds 15 to 25 knots diminishing to 10 to
20 knots. Waves subsiding to calm to 2 feet.
.SUNDAY...Southwest winds 10 to 20 knots. Waves calm to 2 feet.

$$

LSZ263-032000-
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 AM EDT Wed Sep 3 2025

.REST OF TODAY...North winds 20 to 30 knots. A chance of showers.
A slight chance of waterspouts by mid afternoon. Waves 4 to
8 feet occasionally to 10 feet.
.TONIGHT...Northwest winds 20 to 30 knots diminishing to 15 to
25 knots late. A slight chance of waterspouts. A chance of rain
showers. Waves subsiding to 3 to 6 feet occasionally to 8 feet.
.THURSDAY...Northwest winds 15 to 25 knots backing west in the
afternoon. A slight chance of waterspouts. A chance of rain
showers. Waves building to 4 to 7 feet occasionally to 9 feet,
then subsiding to 3 to 6 feet occasionally to 8 feet.
.THURSDAY NIGHT...West winds 15 to 25 knots becoming northwest
10 to 20 knots after midnight. A slight chance of waterspouts. A
chance of showers. Waves subsiding to 2 to 4 feet.
.FRIDAY...Northwest winds 20 to 30 knots backing west by mid
afternoon. A slight chance of waterspouts. A chance of showers.
Waves building to 5 to 8 feet occasionally to 10 feet.
.FRIDAY NIGHT...Northwest winds 20 to 30 knots diminishing to
15 to 25 knots after midnight. Waves subsiding to 3 to 5 feet
occasionally to 7 feet.
.SATURDAY...Northwest winds 10 to 20 knots. Waves subsiding to
1 to 3 feet.
.SUNDAY...Northwest winds 10 to 20 knots becoming southwest 5 to
15 knots. Waves subsiding to calm to 2 feet.

$$

LSZ264-032000-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
1001 AM EDT Wed Sep 3 2025

...GALE WARNING IN EFFECT UNTIL 8 PM EDT THIS EVENING...

.REST OF TODAY...North gales to 35 knots becoming northwest 20 to
30 knots late. A chance of showers. A slight chance of
waterspouts by mid afternoon. Waves 6 to 10 feet occasionally to
13 feet, then building to 7 to 10 feet occasionally to 13 feet.
.TONIGHT...Northwest winds 20 to 30 knots. A slight chance of
waterspouts. Showers. Waves subsiding to 5 to 8 feet occasionally
to 10 feet.
.THURSDAY...Northwest winds 15 to 25 knots backing west in the
afternoon. A slight chance of waterspouts. A chance of showers.
Waves subsiding to 3 to 6 feet occasionally to 8 feet, then
building to 4 to 7 feet occasionally to 9 feet.
.THURSDAY NIGHT...West winds 10 to 20 knots. A chance of showers.
A slight chance of thunderstorms after midnight. A slight chance
of waterspouts after midnight. Waves subsiding to 2 to 4 feet.
.FRIDAY...Northwest winds 20 to 30 knots backing west by mid
afternoon. A slight chance of waterspouts. A chance of showers.
Waves building to 5 to 8 feet occasionally to 10 feet.
.FRIDAY NIGHT...Northwest winds 20 to 30 knots diminishing to
15 to 25 knots after midnight. Waves subsiding to 3 to 6 feet
occasionally to 8 feet.
.SATURDAY...Northwest winds 10 to 20 knots. Waves subsiding to
1 to 3 feet.
.SUNDAY...Northwest winds 10 to 20 knots becoming southwest 5 to
15 knots. Waves subsiding to calm to 2 feet.

$$

LSZ265-032000-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1001 AM EDT Wed Sep 3 2025

.REST OF TODAY...Northwest winds to 30 knots with a few gale
force gusts to 35 knots possible. A chance of showers. A slight
chance of waterspouts by mid afternoon. Waves 5 to 9 feet
occasionally to 11 feet.
.TONIGHT...Northwest winds to 30 knots with a few gale force
gusts to 35 knots possible diminishing to 20 to 30 knots after
midnight. A slight chance of waterspouts. A chance of showers
through midnight. Showers likely after midnight. Waves subsiding
to 4 to 7 feet occasionally to 9 feet.
.THURSDAY...Northwest winds 20 to 30 knots backing west in the
afternoon, then diminishing to 15 to 25 knots late. A slight
chance of waterspouts. Showers likely through early afternoon. A
chance of showers by mid afternoon. Waves subsiding to 3 to
6 feet occasionally to 8 feet.
.THURSDAY NIGHT...Southwest winds 15 to 25 knots becoming west
10 to 20 knots after midnight. A slight chance of waterspouts. A
chance of showers through midnight. Showers likely after
midnight. Waves subsiding to calm to 2 feet.
.FRIDAY...West winds 15 to 25 knots increasing to gales to
35 knots by mid afternoon. A slight chance of waterspouts. A
chance of showers. Waves building to 3 to 6 feet occasionally to
8 feet.
.FRIDAY NIGHT...West winds 20 to 30 knots veering northwest after
midnight. A chance of showers. Waves subsiding to 2 to 4 feet.
.SATURDAY...Northwest winds 15 to 25 knots diminishing to 10 to
20 knots. Waves subsiding to calm to 2 feet.
.SUNDAY...Northwest winds 10 to 20 knots becoming southwest 5 to
15 knots. Waves calm to 2 feet.

$$

LSZ266-032000-
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 AM EDT Wed Sep 3 2025

.REST OF TODAY...Northwest winds to 30 knots with a few gale
force gusts to 35 knots possible. A chance of showers. A slight
chance of waterspouts by mid afternoon. Waves 7 to 10 feet
occasionally to 13 feet.
.TONIGHT...Northwest winds to 30 knots with a few gale force
gusts to 35 knots possible diminishing to 20 to 30 knots after
midnight. A slight chance of waterspouts. Showers. Waves
subsiding to 6 to 9 feet occasionally to 11 feet.
.THURSDAY...West winds 20 to 30 knots diminishing to 15 to
25 knots late. A slight chance of waterspouts. Showers likely.
Waves subsiding to 4 to 7 feet occasionally to 9 feet.
.THURSDAY NIGHT...Southwest winds 10 to 20 knots. A chance of
showers through midnight, then showers likely and a slight chance
of thunderstorms after midnight. Waves subsiding to 2 to 4 feet.
.FRIDAY...West winds 15 to 25 knots increasing to 20 to 30 knots
by mid afternoon. A slight chance of waterspouts. Showers likely
through early afternoon. A chance of showers by mid afternoon.
Waves building to 5 to 8 feet occasionally to 10 feet.
.FRIDAY NIGHT...West winds 20 to 30 knots becoming northwest
15 to 25 knots after midnight. A chance of showers. Waves
subsiding to 4 to 7 feet occasionally to 9 feet.
.SATURDAY...Northwest winds 15 to 25 knots diminishing to 10 to
20 knots. A chance of showers. Waves subsiding to 1 to 3 feet.
.SUNDAY...Northwest winds 10 to 20 knots becoming southwest 5 to
15 knots. Waves subsiding to calm to 2 feet.

$$

LSZ267-032000-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1001 AM EDT Wed Sep 3 2025

.REST OF TODAY...West winds 20 to 30 knots veering northwest in
the afternoon. A slight chance of thunderstorms by late morning.
A chance of showers. Waves 3 to 5 feet occasionally to 7 feet
building to 6 to 9 feet occasionally to 11 feet.
.TONIGHT...Northwest winds 20 to 30 knots backing west late. A
slight chance of waterspouts. A chance of showers through
midnight. Showers likely after midnight. Waves subsiding to 5 to
8 feet occasionally to 10 feet, then building to 6 to 9 feet
occasionally to 11 feet.
.THURSDAY...West winds 20 to 30 knots. A slight chance of
waterspouts. Showers likely. Waves subsiding to 4 to 7 feet
occasionally to 9 feet.
.THURSDAY NIGHT...Southwest winds 15 to 25 knots backing south
after midnight. A slight chance of waterspouts through midnight.
A chance of showers through midnight, then showers after
midnight. Waves subsiding to 2 to 4 feet.
.FRIDAY...West winds 15 to 25 knots increasing to gales to
35 knots by mid afternoon. A slight chance of waterspouts.
Showers through early afternoon. A chance of showers by mid
afternoon. Waves building to 5 to 8 feet occasionally to 10 feet.
.FRIDAY NIGHT...West winds 20 to 30 knots. Showers likely through
midnight, then a chance of showers after midnight. Waves
subsiding to 4 to 7 feet occasionally to 9 feet.
.SATURDAY...Northwest winds 15 to 25 knots. A chance of showers.
Waves subsiding to 2 to 4 feet.
.SUNDAY...Northwest winds 10 to 20 knots backing west. Waves
subsiding to calm to 2 feet.

$$

LSZ261-032000-
MAFOR 0315/
Superior West 11840 11830 15730. Waves 3 to 6 feet.

Superior North Central...GALE WARNING IN EFFECT...11850 11856
11756 14746 11740. Waves 7 to 10 feet this afternoon. Waves 6 to
10 feet subsiding to 5 to 8 feet tonight. Waves 5 to 8 feet
Thursday morning.

Superior South Central 12740 11746 11740 13746 11736. Waves 6 to
10 feet this afternoon and tonight. Waves 5 to 8 feet Thursday
morning.

Superior East 14740 13736 11636. Waves 5 to 8 feet building to 6
to 9 feet this afternoon. Waves 5 to 9 feet tonight and Thursday
morning.

$$

WFO MQT

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