994
FZUS63 KMQT 021401
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1001 AM EDT Tue Sep 2 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 29.9 inch trough over northern Ontario this morning moves over
Lake Superior by this evening as it deepens to 29.7 inches. The
trough becomes a low pressure and deepens to 29.5 inches by
Wednesday afternoon as it lifts back northeast into northern
Ontario. By Thursday morning, the low begins to retrograde as it
deepens to 29.4 inches over far northern Ontario near Hudson Bay,
eventually strengthening to 29.3 inches by Thursday evening. By
Thursday evening, a low of 29.5 inches moves into Minnesota as well,
eventually passing near Lake Superior Friday at around 29.5 inches
before consolidating with the northern Ontario low. The low shifts
northeast into 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 Lower Midwest on Sunday.


LSZ162-022000-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1001 AM EDT Tue Sep 2 2025 /901 AM CDT Tue Sep 2 2025/

.REST OF TODAY...Southwest winds 10 to 20 knots. A chance of
showers and thunderstorms. Waves calm to 2 feet.
.TONIGHT...Southwest winds 10 to 20 knots becoming west 15 to
25 knots after midnight, then veering northwest late. Showers
likely and a chance of thunderstorms through midnight, then a
chance of showers after midnight. Waves building to 3 to 5 feet
occasionally to 7 feet.
.WEDNESDAY...North winds 20 to 30 knots. A chance of showers. A
chance of waterspouts by mid afternoon. Waves building to 3 to
6 feet occasionally to 8 feet.
.WEDNESDAY NIGHT...Northwest winds 15 to 25 knots. A chance of
waterspouts. A chance of showers. Waves subsiding to 2 to 4 feet.
.THURSDAY...West winds 15 to 25 knots. A chance of waterspouts. A
chance of showers. Waves subsiding to 1 to 3 feet.
.THURSDAY NIGHT...West winds 10 to 20 knots veering northwest
after midnight. A chance of showers. Waves building to 2 to
4 feet, then subsiding to calm to 2 feet.
.FRIDAY...Northwest winds 15 to 25 knots. A chance of showers.
Waves building to 3 to 6 feet occasionally to 8 feet, then
subsiding to 2 to 4 feet.
.SATURDAY...Northwest winds 15 to 25 knots diminishing to 10 to
20 knots. A chance of showers. Waves subsiding to calm to 2 feet.

$$

LSZ263-022000-
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 Tue Sep 2 2025

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

$$

LSZ264-022000-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
1001 AM EDT Tue Sep 2 2025

.REST OF TODAY...Southwest winds 5 to 15 knots backing south
late. A slight chance of showers and thunderstorms by mid
afternoon. Waves calm to 2 feet building to 1 to 3 feet, then
subsiding to calm to 2 feet.
.TONIGHT...South winds 5 to 15 knots becoming southwest 10 to
20 knots after midnight, then becoming northwest 20 to 30 knots
late. Showers and a chance of thunderstorms. Waves building to
3 to 6 feet occasionally to 8 feet.
.WEDNESDAY...North winds 20 to 30 knots backing northwest late. A
slight chance of thunderstorms through early afternoon. A chance
of showers. Waves building to 5 to 8 feet occasionally to
10 feet.
.WEDNESDAY NIGHT...Northwest winds 20 to 30 knots diminishing to
15 to 25 knots after midnight. A chance of waterspouts. A chance
of showers through midnight. Showers likely after midnight. Waves
subsiding to 3 to 6 feet occasionally to 8 feet.
.THURSDAY...Northwest winds 15 to 25 knots backing west by mid
afternoon. A chance of waterspouts. A chance of showers. Waves
subsiding to 3 to 5 feet occasionally to 7 feet.
.THURSDAY NIGHT...West winds 10 to 20 knots. A chance of showers.
Waves subsiding to 2 to 4 feet.
.FRIDAY...West winds 20 to 30 knots veering northwest. A chance
of showers. Waves building to 4 to 7 feet occasionally to 9 feet,
then subsiding to 3 to 6 feet occasionally to 8 feet.
.SATURDAY...Northwest winds 15 to 25 knots diminishing to 10 to
20 knots. A chance of showers. Waves subsiding to 2 to 4 feet.

$$

LSZ265-022000-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1001 AM EDT Tue Sep 2 2025

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

$$

LSZ266-022000-
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 Tue Sep 2 2025

.REST OF TODAY...Southwest winds 10 to 20 knots backing southeast
late. Waves calm to 2 feet.
.TONIGHT...South winds 15 to 25 knots veering southwest late. A
slight chance of showers through midnight. A chance of
thunderstorms. Showers after midnight. Waves building to 2 to
4 feet.
.WEDNESDAY...Northwest winds 15 to 25 knots increasing to 20 to
30 knots in the afternoon. A slight chance of thunderstorms
through early afternoon. A chance of showers. Waves building to
5 to 8 feet occasionally to 10 feet.
.WEDNESDAY NIGHT...Northwest winds 20 to 30 knots diminishing to
15 to 25 knots after midnight. A chance of waterspouts. A chance
of showers. Waves subsiding to 3 to 6 feet occasionally to
8 feet.
.THURSDAY...West winds 15 to 25 knots. A chance of waterspouts.
Showers likely through early afternoon. A chance of showers by
mid afternoon. Waves 3 to 6 feet occasionally to 8 feet.
.THURSDAY NIGHT...Southwest winds 10 to 20 knots. Showers likely
after midnight. Waves subsiding to 2 to 4 feet.
.FRIDAY...West winds 20 to 30 knots diminishing to 15 to
25 knots. A chance of showers. Waves building to 4 to 7 feet
occasionally to 9 feet.
.SATURDAY...Northwest winds 15 to 25 knots. A chance of showers.
Waves subsiding to 3 to 5 feet occasionally to 7 feet.

$$

LSZ267-022000-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1001 AM EDT Tue Sep 2 2025

.REST OF TODAY...South winds 10 to 20 knots becoming southwest
5 to 15 knots in the afternoon, then becoming southeast 10 to
20 knots late. Waves calm to 2 feet.
.TONIGHT...South winds 15 to 25 knots. A chance of showers and a
slight chance of thunderstorms after midnight. Waves building to
2 to 4 feet, then subsiding to 1 to 3 feet.
.WEDNESDAY...Southwest winds 15 to 25 knots becoming west 20 to
30 knots in the afternoon, then veering northwest late. Showers
through early afternoon. A chance of thunderstorms. A chance of
showers by mid afternoon. Waves building to 5 to 8 feet
occasionally to 10 feet.
.WEDNESDAY NIGHT...Northwest winds 15 to 25 knots backing west
after midnight. A chance of showers. A slight chance of
waterspouts after midnight. Waves subsiding to 3 to 6 feet
occasionally to 8 feet.
.THURSDAY...West winds 15 to 25 knots. A chance of waterspouts. A
chance of showers through early afternoon. Showers likely by mid
afternoon. Waves 3 to 6 feet occasionally to 8 feet.
.THURSDAY NIGHT...Southwest winds 15 to 25 knots. A chance of
showers through midnight, then showers likely after midnight.
Waves subsiding to 2 to 4 feet.
.FRIDAY...West winds 20 to 30 knots. A chance of showers. Waves
building to 4 to 8 feet occasionally to 10 feet.
.SATURDAY...West winds 15 to 25 knots veering northwest. A chance
of showers. Waves subsiding to 3 to 5 feet occasionally to
7 feet.

$$

LSZ261-022000-
MAFOR 0215/
Superior West 13520 11526 11620 11630 12730. A chance of
thunderstorms this afternoon and evening. Waves 1 to 2 feet this
afternoon. Waves 1 to 3 feet building to 2 to 4 feet tonight.
Waves 3 to 5 feet Wednesday morning.

Superior North Central 12520 12410 12526 11746 11740. A chance of
thunderstorms tonight. Waves 1 to 3 feet this afternoon and
tonight. Waves 5 to 8 feet Wednesday morning.

Superior South Central 11410 11310 11320 12420 11526 11536 11730.
A chance of thunderstorms overnight and Wednesday morning. Waves
2 feet or less this afternoon. Waves 1 to 3 feet tonight. Waves 2
to 4 feet building to 3 to 5 feet Wednesday morning.

Superior East 11510 11400 11310 11420 12430 11436 11526. A chance
of thunderstorms overnight and Wednesday morning. Waves 1 to 2
feet this afternoon. Waves 1 to 3 feet building to 2 to 4 feet
tonight. Waves 2 to 4 feet Wednesday morning.

$$

WFO MQT

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