151
FZUS63 KMQT 180201
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1001 PM EDT Wed Sep 17 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 30.3 inch high over Manitoba gradually shifts over northern
Ontario tonight through Friday and strengthens to 30.4 inches on
Saturday over eastern Ontario and Quebec. The 30.4 inch high will
move to New England by Sunday morning. This brings 30.2 inch ridging
back over Lake Superior Thursday and Friday, weakening to 30.0
inches by the end of the day Saturday. Troughing then begins to
spread over Lake Superior Sunday into the beginning of next week as
low pressure deepens over the Canadian Prairie to around 29.5 inches.


LSZ162-180800-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1001 PM EDT Wed Sep 17 2025 /901 PM CDT Wed Sep 17 2025/

.REST OF TONIGHT...Northeast winds 5 to 15 knots becoming east
10 to 20 knots after midnight, then backing northeast late. A
slight chance of showers after midnight. Waves calm to 2 feet
building to 1 to 3 feet.
.THURSDAY...Northeast winds 15 to 25 knots veering east in the
afternoon. A slight chance of showers. Waves building to 3 to
6 feet occasionally to 8 feet.
.THURSDAY NIGHT...East winds 15 to 25 knots. A slight chance of
showers. A slight chance of thunderstorms after midnight. Waves
subsiding to 3 to 5 feet occasionally to 7 feet.
.FRIDAY...East winds 15 to 25 knots increasing to 20 to 30 knots
by mid afternoon. A slight chance of thunderstorms through early
afternoon. A slight 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.
.FRIDAY NIGHT...East winds 15 to 25 knots diminishing to 10 to
20 knots after midnight. A chance of showers and a slight chance
of thunderstorms. Waves subsiding to calm to 2 feet.
.SATURDAY...Southeast winds 10 to 20 knots backing east by mid
afternoon. Showers likely and a chance of thunderstorms. Waves
calm to 2 feet.
.SATURDAY NIGHT...East winds 5 to 15 knots veering south after
midnight. A chance of showers and thunderstorms. Waves calm to
2 feet.
.SUNDAY...South winds 5 to 15 knots veering southwest. A chance
of showers. Waves calm to 2 feet.
.MONDAY...South winds 5 to 15 knots becoming west 10 to 20 knots.
A chance of showers. Waves calm to 2 feet.

$$

LSZ263-180800-
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 Wed Sep 17 2025

.REST OF TONIGHT...Northeast winds 5 to 15 knots increasing to
10 to 20 knots late. Waves calm to 2 feet building to 1 to
3 feet.
.THURSDAY...Northeast winds 10 to 20 knots veering east in the
afternoon. A slight chance of showers. Waves building to 3 to
6 feet occasionally to 8 feet.
.THURSDAY NIGHT...East winds 10 to 20 knots. A slight chance of
showers. Waves subsiding to 2 to 4 feet.
.FRIDAY...East winds 15 to 25 knots. A slight chance of showers.
Waves building to 3 to 6 feet occasionally to 8 feet.
.FRIDAY NIGHT...East winds 10 to 20 knots becoming southeast 5 to
15 knots after midnight. A slight chance of showers. Waves
subsiding to calm to 2 feet.
.SATURDAY...Southeast winds 5 to 15 knots. A chance of showers.
Waves building to 1 to 3 feet.
.SATURDAY NIGHT...South winds 5 to 15 knots. A chance of showers
and thunderstorms. Waves subsiding to calm to 2 feet.
.SUNDAY...South winds 5 to 15 knots. A chance of showers and
thunderstorms. Waves calm to 2 feet.
.MONDAY...Southwest winds 5 to 15 knots. Waves calm to 2 feet.

$$

LSZ264-180800-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
1001 PM EDT Wed Sep 17 2025

.REST OF TONIGHT...North winds 5 to 15 knots becoming northeast
10 to 20 knots late. Waves calm to 2 feet building to 1 to
3 feet.
.THURSDAY...Northeast winds 10 to 20 knots. Waves 1 to 3 feet.
.THURSDAY NIGHT...Northeast winds 5 to 15 knots veering east
after midnight. Waves subsiding to calm to 2 feet, then building
to 2 to 4 feet.
.FRIDAY...East winds 10 to 20 knots. Waves building to 2 to
4 feet, then subsiding to 1 to 3 feet.
.FRIDAY NIGHT...East winds 10 to 20 knots veering southeast after
midnight. Waves subsiding to calm to 2 feet.
.SATURDAY...Southeast winds 10 to 20 knots. A chance of showers.
Waves building to 2 to 4 feet.
.SATURDAY NIGHT...South winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. A chance of showers and thunderstorms.
Waves subsiding to 1 to 3 feet.
.SUNDAY...South winds 5 to 15 knots. A chance of showers and
thunderstorms. Waves subsiding to calm to 2 feet.
.MONDAY...South winds 5 to 15 knots veering southwest. Waves calm
to 2 feet.

$$

LSZ265-180800-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1001 PM EDT Wed Sep 17 2025

.REST OF TONIGHT...Northwest winds 5 to 15 knots veering north
after midnight, then increasing to 10 to 20 knots late. Waves
calm to 2 feet.
.THURSDAY...Northeast winds 10 to 20 knots. Waves building to
1 to 3 feet, then subsiding to calm to 2 feet.
.THURSDAY NIGHT...Northeast winds 10 to 20 knots veering east
after midnight. A slight chance of showers through midnight.
Waves building to 1 to 3 feet.
.FRIDAY...East winds 10 to 20 knots. Waves 1 to 3 feet.
.FRIDAY NIGHT...East winds 10 to 20 knots veering southeast after
midnight. Waves subsiding to calm to 2 feet.
.SATURDAY...Southeast winds 15 to 25 knots. A chance of showers.
Waves calm to 2 feet.
.SATURDAY NIGHT...Southeast winds 15 to 25 knots becoming south
10 to 20 knots after midnight. A chance of showers through
midnight. A chance of thunderstorms. Showers likely after
midnight. Waves calm to 2 feet.
.SUNDAY...South winds 10 to 20 knots. A chance of showers and
thunderstorms. Waves calm to 2 feet.
.MONDAY...South winds 10 to 20 knots veering southwest. A chance
of showers. Waves calm to 2 feet.

$$

LSZ266-180800-
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 Wed Sep 17 2025

.REST OF TONIGHT...Northwest winds 5 to 15 knots veering north
after midnight, then increasing to 10 to 20 knots late. Patchy
fog. Waves calm to 2 feet building to 1 to 3 feet.
.THURSDAY...Northeast winds 10 to 20 knots. Waves subsiding to
calm to 2 feet.
.THURSDAY NIGHT...Northeast winds 10 to 20 knots veering east
after midnight. Waves building to 1 to 3 feet.
.FRIDAY...East winds 10 to 20 knots. Waves 1 to 3 feet.
.FRIDAY NIGHT...East winds 10 to 20 knots veering southeast after
midnight. Waves subsiding to calm to 2 feet.
.SATURDAY...Southeast winds 10 to 20 knots increasing to 15 to
25 knots by mid afternoon. Waves building to 2 to 4 feet.
.SATURDAY NIGHT...Southeast winds 15 to 25 knots veering south
after midnight. A chance of showers through midnight. A chance of
thunderstorms. Showers likely after midnight. Waves subsiding to
1 to 3 feet.
.SUNDAY...South winds 10 to 20 knots. A chance of showers and
thunderstorms. Waves subsiding to calm to 2 feet.
.MONDAY...South winds 10 to 20 knots. A chance of showers. Waves
calm to 2 feet.

$$

LSZ267-180800-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1001 PM EDT Wed Sep 17 2025

.REST OF TONIGHT...West winds 10 to 20 knots veering north late.
Areas of dense fog by midnight, then patchy fog after midnight.
Waves calm to 2 feet.
.THURSDAY...North winds 10 to 20 knots veering northeast in the
afternoon. Patchy fog through early afternoon. Waves calm to
2 feet.
.THURSDAY NIGHT...Northeast winds 10 to 20 knots veering east
after midnight. Waves building to 1 to 3 feet.
.FRIDAY...East winds 10 to 20 knots diminishing to 5 to 15 knots
by mid afternoon. Waves subsiding to calm to 2 feet.
.FRIDAY NIGHT...East winds 10 to 20 knots veering southeast after
midnight. Waves calm to 2 feet.
.SATURDAY...Southeast winds 10 to 20 knots increasing to 15 to
25 knots by mid afternoon. Waves building to 1 to 3 feet.
.SATURDAY NIGHT...Southeast winds 15 to 25 knots. A chance of
showers. A chance of thunderstorms after midnight. Waves building
to 2 to 4 feet, then subsiding to 1 to 3 feet.
.SUNDAY...South winds 10 to 20 knots. Showers likely. Waves
subsiding to calm to 2 feet.
.MONDAY...South winds 10 to 20 knots. A chance of showers. Waves
calm to 2 feet.

$$

LSZ261-180800-
MAFOR 1803/
Superior West 11110 13120 11220 13230. Waves 2 feet or less
building to 2 to 3 feet overnight. Waves 2 to 4 feet building to
3 to 5 feet Thursday. Waves 3 to 5 feet Thursday evening.

Superior North Central 12810 14120 12110. Waves 1 to 3 feet.

Superior South Central 11700 12810 11110 12120 12110. Waves 2
feet or less overnight. Waves 1 to 3 feet Thursday and Thursday
evening.

Superior East 11710 12810 14110 11110. Waves 1 to 3 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