598
FZUS63 KMQT 090201
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1001 PM EDT Mon Sep 8 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...

30.1 inch ridging over Lake Superior shifts east as parent high
pushes east towards New England tonight. A 29.8 inch low over the
Canadian Prairies tracks east into northern Ontario and James Bay
while weakening to 29.9 inches by Tuesday, resulting in 29.9 inch
troughing over Lake Superior late tonight through Tuesday. Ridging
returns to Lake Superior on Wednesday as a 30.3 inch high pressure
builds over far northern Ontario. 30.2 inch ridging persists over
Lake Superior through Friday as the high shifts east to the St.
Lawrence Seaway and New England.


LSZ162-090800-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1001 PM EDT Mon Sep 8 2025 /901 PM CDT Mon Sep 8 2025/

.REST OF TONIGHT...South winds 10 to 20 knots increasing to 15 to
25 knots after midnight. Showers by midnight. A chance of
thunderstorms. A chance of showers after midnight. Waves 1 to
3 feet building to 3 to 5 feet occasionally to 7 feet, then
subsiding to 2 to 4 feet.
.TUESDAY...South winds 15 to 25 knots becoming southwest 10 to
20 knots in the afternoon, then diminishing to 5 to 15 knots
late. A chance of showers and a slight chance of thunderstorms.
Patchy fog by mid afternoon. Waves subsiding to calm to 2 feet.
.TUESDAY NIGHT...Northeast winds 5 to 15 knots. Patchy fog
through midnight. A slight chance of showers through midnight.
Waves calm to 2 feet.
.WEDNESDAY...Northeast winds 5 to 15 knots increasing to 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...East winds 5 to 15 knots backing northeast
after midnight. Waves calm to 2 feet.
.THURSDAY...East winds 5 to 15 knots increasing to 10 to 20 knots
by mid afternoon. Waves calm to 2 feet.
.THURSDAY NIGHT...Northeast winds 5 to 15 knots veering east
after midnight. Waves calm to 2 feet.
.FRIDAY...East winds 5 to 15 knots backing northeast. A chance of
showers. Waves calm to 2 feet.
.SATURDAY...Northeast winds 10 to 20 knots. Waves building to
1 to 3 feet.

$$

LSZ263-090800-
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 PM EDT Mon Sep 8 2025

.REST OF TONIGHT...South winds 10 to 20 knots increasing to 15 to
25 knots after midnight, then becoming southwest 20 to 30 knots
late. Showers and a chance of thunderstorms. Waves 1 to 3 feet
building to 3 to 5 feet occasionally to 7 feet, then subsiding to
2 to 4 feet.
.TUESDAY...Southwest winds 20 to 30 knots diminishing to 5 to
15 knots. A chance of showers and a slight chance of
thunderstorms. Waves building to 3 to 6 feet occasionally to
8 feet, then subsiding to calm to 2 feet.
.TUESDAY NIGHT...Southwest winds less than 10 knots veering north
after midnight, then becoming northeast 5 to 15 knots late.
Patchy fog through midnight. A slight chance of showers through
midnight. Waves calm to 2 feet.
.WEDNESDAY...Northeast 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...East winds 5 to 15 knots veering southeast
after midnight. Waves calm to 2 feet.
.FRIDAY...South winds 5 to 15 knots backing east. A chance of
showers. Waves calm to 2 feet.
.SATURDAY...Northeast winds 5 to 15 knots veering east. Waves
building to 1 to 3 feet.

$$

LSZ264-090800-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
1001 PM EDT Mon Sep 8 2025

.REST OF TONIGHT...Southeast winds 10 to 20 knots becoming south
15 to 25 knots after midnight, then increasing to 20 to 30 knots
late. Showers and a chance of thunderstorms. Patchy fog after
midnight. Waves 1 to 3 feet building to 3 to 5 feet occasionally
to 7 feet.
.TUESDAY...Southwest winds 20 to 30 knots diminishing to 10 to
20 knots. Patchy fog through early afternoon. A chance of
showers. Waves building to 3 to 6 feet occasionally to 8 feet,
then subsiding to 1 to 3 feet.
.TUESDAY NIGHT...Southwest winds less than 10 knots backing
northeast after midnight, then increasing to 5 to 15 knots late.
Patchy fog through midnight. A slight chance of showers through
midnight. Waves subsiding to calm to 2 feet.
.WEDNESDAY...Northeast winds 5 to 15 knots. Waves calm to 2 feet.
.WEDNESDAY NIGHT...East winds 5 to 15 knots diminishing to less
than 10 knots after midnight. Waves calm to 2 feet.
.THURSDAY...East winds 5 to 15 knots. Waves calm to 2 feet.
.THURSDAY NIGHT...Southeast winds 5 to 15 knots. Waves calm to
2 feet.
.FRIDAY...South winds 5 to 15 knots backing southeast. Waves calm
to 2 feet.
.SATURDAY...Northeast winds 5 to 15 knots. Waves calm to 2 feet.

$$

LSZ265-090800-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1001 PM EDT Mon Sep 8 2025

.REST OF TONIGHT...South winds 20 to 30 knots. A chance of
showers by midnight. A chance of thunderstorms. Showers after
midnight. Patchy fog after midnight. Waves 2 to 4 feet subsiding
to 1 to 3 feet.
.TUESDAY...Southwest winds 20 to 30 knots diminishing to 15 to
25 knots in the afternoon, then becoming south 10 to 20 knots
late. A chance of showers and a slight chance of thunderstorms.
Waves building to 3 to 5 feet occasionally to 7 feet, then
subsiding to calm to 2 feet.
.TUESDAY NIGHT...South winds 5 to 15 knots veering southwest
late. Patchy fog through midnight. A chance of showers. Waves
calm to 2 feet.
.WEDNESDAY...Northeast winds 5 to 15 knots increasing to 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...Northeast winds 5 to 15 knots veering east
after midnight. Waves calm to 2 feet.
.THURSDAY...East winds 5 to 15 knots. Waves calm to 2 feet.
.THURSDAY NIGHT...Southeast winds 5 to 15 knots veering south
after midnight. Waves calm to 2 feet.
.FRIDAY...Southeast winds 10 to 20 knots veering southwest. A
chance of showers. Waves calm to 2 feet.
.SATURDAY...Northeast winds 10 to 20 knots. Waves calm to 2 feet.

$$

LSZ266-090800-
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 PM EDT Mon Sep 8 2025

.REST OF TONIGHT...South winds 20 to 30 knots. A chance of
showers by midnight. A slight chance of thunderstorms. Showers
likely after midnight. Patchy fog after midnight. Waves 2 to
4 feet building to 3 to 6 feet occasionally to 8 feet, then
subsiding to 3 to 5 feet occasionally to 7 feet.
.TUESDAY...Southwest winds 20 to 30 knots diminishing to 15 to
25 knots in the afternoon, then becoming south 10 to 20 knots
late. Patchy fog through early afternoon. A chance of showers and
a slight chance of thunderstorms. Waves building to 4 to 7 feet
occasionally to 9 feet, then subsiding to 2 to 4 feet.
.TUESDAY NIGHT...South winds 5 to 15 knots veering southwest
late. Showers likely and a slight chance of thunderstorms through
midnight, then a chance of showers after midnight. Waves
subsiding to calm to 2 feet.
.WEDNESDAY...Northeast winds 5 to 15 knots. Waves calm to 2 feet.
.WEDNESDAY NIGHT...Northeast winds 5 to 15 knots. Waves calm to
2 feet.
.THURSDAY...East winds 5 to 15 knots. Waves calm to 2 feet.
.THURSDAY NIGHT...Southeast winds 5 to 15 knots veering south
after midnight. Waves calm to 2 feet.
.FRIDAY...South winds 10 to 20 knots. A chance of showers. Waves
calm to 2 feet.
.SATURDAY...North winds 10 to 20 knots veering northeast. Waves
calm to 2 feet.

$$

LSZ267-090800-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1001 PM EDT Mon Sep 8 2025

.REST OF TONIGHT...South winds 20 to 30 knots. A chance of
showers. A slight chance of thunderstorms after midnight. Waves
2 to 4 feet building to 3 to 5 feet occasionally to 7 feet, then
subsiding to 2 to 4 feet.
.TUESDAY...Southwest winds 20 to 30 knots becoming south 15 to
25 knots late. Showers likely and a slight chance of
thunderstorms through early afternoon, then a chance of showers
by mid afternoon. Waves building to 3 to 6 feet occasionally to
8 feet, then subsiding to 2 to 4 feet.
.TUESDAY NIGHT...South winds 10 to 20 knots diminishing to 5 to
15 knots late. Showers likely through midnight, then a chance of
showers after midnight. Waves subsiding to calm to 2 feet.
.WEDNESDAY...South winds 5 to 15 knots backing north by mid
afternoon. A slight chance of showers through early afternoon.
Waves calm to 2 feet.
.WEDNESDAY NIGHT...Northeast winds 5 to 15 knots becoming east
10 to 20 knots after midnight. Waves calm to 2 feet.
.THURSDAY...East winds 5 to 15 knots. Waves calm to 2 feet.
.THURSDAY NIGHT...East winds 5 to 15 knots becoming south 10 to
20 knots after midnight. Waves calm to 2 feet.
.FRIDAY...Southeast winds 10 to 20 knots veering south. A chance
of showers. Waves calm to 2 feet.
.SATURDAY...North winds 10 to 20 knots veering northeast. A
chance of showers. Waves calm to 2 feet.

$$

LSZ261-090800-
MAFOR 0903/
Superior West 12436 12430 11530 12510 11400. A chance of
thunderstorms overnight. Waves 1 to 3 feet building to 2 to 4
feet overnight. Waves 3 to 5 feet subsiding to 1 to 2 feet
Tuesday. Waves 2 feet or less Tuesday evening.

Superior North Central 13436 12530 11520 11510 11500. A chance of
thunderstorms overnight. Waves 1 to 3 feet building to 3 to 5
feet overnight. Waves 3 to 5 feet subsiding to 2 to 4 feet
Tuesday. Waves 1 to 3 feet Tuesday evening.

Superior South Central 11430 12436 11546 11530 11420 11410 11400.
A chance of thunderstorms overnight. Waves 2 to 4 feet building
to 3 to 5 feet, then subsiding to 2 to 4 feet overnight. Waves 2
to 4 feet subsiding to 1 to 3 feet Tuesday. Waves 2 feet or less
Tuesday evening.

Superior East 11440 13446 11540 11536 11420 11416. Waves 3 to 5
feet overnight. Waves 3 to 5 feet building to 4 to 7 feet
Tuesday. Waves 2 to 4 feet Tuesday evening.

$$

WFO MQT

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