509
FZUS63 KMQT 280201
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1001 PM EDT Wed Aug 27 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 weak 29.9 inch trough is passing south over the MI Upper Peninsula
tonight while 30.2 inch highs remain over far northern Ontario and
Appalachia respectively. Thursday, the northern high will move over
the lake, residing over the Upper Great Lakes through the weekend
before merging with a high of 30.2 inches over the Northeast US
Monday. Tuesday, a 29.7 inch trough will approach Lake Superior from
the northwest.


LSZ162-280800-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1001 PM EDT Wed Aug 27 2025 /901 PM CDT Wed Aug 27 2025/

.REST OF TONIGHT...North winds 10 to 20 knots veering northeast
after midnight, then increasing to 15 to 25 knots late. A slight
chance of showers by midnight. Waves calm to 2 feet building to
3 to 5 feet occasionally to 7 feet.
.THURSDAY...Northeast winds 15 to 25 knots veering east in the
afternoon, then diminishing to 10 to 20 knots late. Waves
building to 3 to 6 feet occasionally to 8 feet, then subsiding to
2 to 4 feet.
.THURSDAY NIGHT...East winds 5 to 15 knots veering southeast
late. Waves subsiding to calm to 2 feet.
.FRIDAY...South winds 5 to 15 knots. Waves calm to 2 feet.
.FRIDAY NIGHT...Southeast winds 5 to 15 knots veering west after
midnight. Waves calm to 2 feet.
.SATURDAY...Southwest winds 5 to 15 knots. Waves calm to 2 feet.
.SATURDAY NIGHT...Southwest winds 5 to 15 knots veering west
after midnight. Waves calm to 2 feet.
.SUNDAY...Southwest winds 5 to 15 knots. Waves calm to 2 feet.
.MONDAY...Southwest winds 5 to 15 knots. Waves calm to 2 feet.

$$

LSZ263-280800-
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 Aug 27 2025

.REST OF TONIGHT...North winds 5 to 15 knots becoming northeast
15 to 25 knots after midnight. A slight chance of showers by
midnight. Waves 2 to 4 feet building to 3 to 5 feet occasionally
to 7 feet.
.THURSDAY...Northeast winds 15 to 25 knots diminishing to 10 to
20 knots in the afternoon. Waves building to 3 to 6 feet
occasionally to 8 feet, then subsiding to 2 to 4 feet.
.THURSDAY NIGHT...East winds 5 to 15 knots veering southeast
after midnight, then becoming south less than 10 knots late.
Waves subsiding to calm to 2 feet.
.FRIDAY...South winds 5 to 15 knots veering southwest by mid
afternoon. Waves calm to 2 feet.
.FRIDAY NIGHT...South winds 5 to 15 knots veering southwest after
midnight. Waves calm to 2 feet.
.SATURDAY...Southwest winds 5 to 15 knots. Waves calm to 2 feet.
.SATURDAY NIGHT...Southwest winds 5 to 15 knots. Waves calm to
2 feet.
.SUNDAY...Southwest winds 5 to 15 knots. Waves calm to 2 feet.
.MONDAY...Southwest winds 5 to 15 knots backing south. Waves calm
to 2 feet.

$$

LSZ264-280800-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
1001 PM EDT Wed Aug 27 2025

.REST OF TONIGHT...North winds 10 to 20 knots becoming northeast
15 to 25 knots after midnight. A slight chance of showers by
midnight. Waves 3 to 6 feet occasionally to 8 feet.
.THURSDAY...Northeast winds 10 to 20 knots backing north late.
Waves subsiding to 2 to 4 feet.
.THURSDAY NIGHT...North winds 5 to 15 knots becoming southwest
less than 10 knots after midnight. Waves subsiding to calm to
2 feet.
.FRIDAY...Southwest winds 5 to 15 knots. Waves calm to 2 feet.
.FRIDAY NIGHT...South winds 5 to 15 knots veering southwest after
midnight. Waves calm to 2 feet.
.SATURDAY...West winds 5 to 15 knots backing southwest by mid
afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...Southwest winds 5 to 15 knots. Waves calm to
2 feet.
.SUNDAY...Southwest winds 5 to 15 knots. Waves calm to 2 feet.
.MONDAY...Southwest winds 5 to 15 knots backing south. Waves calm
to 2 feet.

$$

LSZ265-280800-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1001 PM EDT Wed Aug 27 2025

.REST OF TONIGHT...Northwest winds 10 to 20 knots becoming north
15 to 25 knots after midnight, then becoming northeast 20 to
30 knots late. A chance of showers by midnight. Waves 1 to 3 feet
building to 3 to 6 feet occasionally to 8 feet.
.THURSDAY...Northeast winds 20 to 30 knots diminishing to 15 to
25 knots in the afternoon, then becoming north 10 to 20 knots
late. Waves building to 4 to 7 feet occasionally to 9 feet, then
subsiding to 3 to 5 feet occasionally to 7 feet.
.THURSDAY NIGHT...North winds 5 to 15 knots veering northeast
after midnight, then backing north late. Waves subsiding to calm
to 2 feet.
.FRIDAY...West winds 5 to 15 knots backing southeast by mid
afternoon. Waves calm to 2 feet.
.FRIDAY NIGHT...South winds 5 to 15 knots veering southwest after
midnight. Waves calm to 2 feet.
.SATURDAY...West winds 5 to 15 knots backing southwest by mid
afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...Southwest winds 5 to 15 knots. Waves calm to
2 feet.
.SUNDAY...Southwest winds 5 to 15 knots. Waves calm to 2 feet.
.MONDAY...Southwest winds 5 to 15 knots backing south. Waves calm
to 2 feet.

$$

LSZ266-280800-
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 Aug 27 2025

.REST OF TONIGHT...Northwest winds 10 to 20 knots becoming north
15 to 25 knots after midnight, then becoming northeast 20 to
30 knots late. A chance of showers by midnight. Waves 3 to 6 feet
occasionally to 8 feet.
.THURSDAY...Northeast winds 20 to 30 knots backing north in the
afternoon, then diminishing to 10 to 20 knots late. Waves
building to 4 to 7 feet occasionally to 9 feet, then subsiding to
3 to 5 feet occasionally to 7 feet.
.THURSDAY NIGHT...North winds 5 to 15 knots. Waves subsiding to
calm to 2 feet.
.FRIDAY...North winds 5 to 15 knots backing southwest by mid
afternoon. Waves calm to 2 feet.
.FRIDAY NIGHT...South winds 5 to 15 knots veering southwest after
midnight. Waves calm to 2 feet.
.SATURDAY...Southwest winds 5 to 15 knots veering west by mid
afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...Southwest winds 5 to 15 knots. Waves calm to
2 feet.
.SUNDAY...Southwest winds 5 to 15 knots backing south. Waves calm
to 2 feet.
.MONDAY...South winds 5 to 15 knots. Waves calm to 2 feet.

$$

LSZ267-280800-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1001 PM EDT Wed Aug 27 2025

.REST OF TONIGHT...Northwest winds 10 to 20 knots becoming north
15 to 25 knots after midnight, then becoming northeast 20 to
30 knots late. A chance of showers by midnight. Waves 3 to 6 feet
occasionally to 8 feet.
.THURSDAY...North winds 20 to 30 knots. Waves subsiding to 3 to
5 feet occasionally to 7 feet.
.THURSDAY NIGHT...North winds 15 to 25 knots becoming northeast
10 to 20 knots after midnight, then backing north late. Waves
subsiding to calm to 2 feet.
.FRIDAY...North winds 5 to 15 knots backing northwest by mid
afternoon. Waves calm to 2 feet.
.FRIDAY NIGHT...Northwest winds 5 to 15 knots backing west after
midnight. Waves calm to 2 feet.
.SATURDAY...Southwest winds 5 to 15 knots veering west by mid
afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...Southwest winds 5 to 15 knots. Waves calm to
2 feet.
.SUNDAY...Southwest winds 5 to 15 knots backing south. Waves calm
to 2 feet.
.MONDAY...South winds 5 to 15 knots. Waves calm to 2 feet.

$$

LSZ261-280800-
MAFOR 2803/
Superior West 11820 13130 11120 12220 11210. A chance of showers
late this evening. Waves 1 to 2 feet building to 3 to 5 feet
overnight. Waves 3 to 6 feet Thursday. Waves 2 to 4 feet Thursday
evening.

Superior North Central 14130 11130 11120 11820 11700. Waves 3 to
6 feet overnight and Thursday. Waves 2 to 4 feet subsiding to 1
to 2 feet Thursday evening.

Superior South Central 11720 14130 11830 11820 11810. A chance of
showers overnight. Waves 2 to 4 feet building to 4 to 6 feet
overnight. Waves 4 to 7 feet Thursday. Waves 3 to 5 feet
subsiding to 2 to 4 feet Thursday evening.

Superior East 11820 13130 13830 11820. A chance of showers late
this evening. Waves 3 to 6 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