217
FZUS63 KMQT 160201
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1001 PM EDT Sat Aug 15 2026

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 low between Thunder Bay and the Northwest Angle builds
into Lake Superior at 29.8 inches later tonight. The associated low
continues to deepen to 29.7 inches as it reaches Quebec just south
of James Bay late Sunday afternoon. Meanwhile, a 30.2 inch high over
the Northern Plains on Sunday weakens to 30.0 inches as it slides
generally south of the Great Lakes early in the week. This allows
29.8 inch troughing to return to Lake Superior on Tuesday morning.
Around the same time, a 30.1 inch high over the Canadian Prairies
and Northern Plains weakens to 30.0 inches and heads east into the
Great Lakes for Wednesday and Thursday. This ridging shifts east
into New England Thursday night into Friday as a 29.8 inch trough
builds over Lake Superior from a parent low of at least 29.7 inches
over northern Ontario.



LSZ162-160800-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1001 PM EDT Sat Aug 15 2026 /901 PM CDT Sat Aug 15 2026/

.REST OF TONIGHT...Northeast winds 5 to 15 knots backing west
late. A slight chance of thunderstorms by midnight. A chance of
showers. Waves 1 to 3 feet subsiding to calm to 2 feet.
.SUNDAY...West winds 10 to 20 knots. Waves calm to 2 feet.
.SUNDAY NIGHT...Northwest winds 10 to 20 knots diminishing to
5 to 15 knots after midnight, then backing west late. Waves calm
to 2 feet.
.MONDAY...West winds 5 to 15 knots becoming southwest 15 to
25 knots by mid afternoon. Waves building to 1 to 3 feet.
.MONDAY NIGHT...Southwest winds 10 to 20 knots veering west after
midnight. A slight chance of thunderstorms through midnight. A
chance of showers. Waves subsiding to calm to 2 feet.
.TUESDAY...West winds 10 to 20 knots diminishing to 5 to 15 knots
by mid afternoon. Waves calm to 2 feet.
.TUESDAY NIGHT...Northwest winds 5 to 15 knots. Waves calm to
2 feet.
.WEDNESDAY...Southwest winds 5 to 15 knots veering north. Waves
calm to 2 feet.
.THURSDAY...South winds 5 to 15 knots veering southwest. Waves
calm to 2 feet.

$$

LSZ263-160800-
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 Sat Aug 15 2026

.REST OF TONIGHT...East winds 5 to 15 knots backing northeast
after midnight, then backing northwest late. Showers likely and a
chance of thunderstorms by midnight, then a slight chance of
showers after midnight. Waves 1 to 3 feet subsiding to calm to
2 feet.
.SUNDAY...West winds 10 to 20 knots. A slight chance of showers
through early afternoon. Waves building to 1 to 3 feet.
.SUNDAY NIGHT...West winds 10 to 20 knots becoming northwest 5 to
15 knots after midnight, then backing west late. Waves subsiding
to calm to 2 feet.
.MONDAY...West winds 10 to 20 knots becoming southwest 15 to
25 knots by mid afternoon. Waves building to 2 to 4 feet.
.MONDAY NIGHT...Southwest winds 15 to 25 knots becoming west
10 to 20 knots after midnight. A slight chance of thunderstorms
through midnight. A chance of showers. Waves subsiding to calm to
2 feet.
.TUESDAY...West winds 10 to 20 knots diminishing to 5 to 15 knots
by mid afternoon. Waves calm to 2 feet.
.TUESDAY NIGHT...West winds 5 to 15 knots veering northwest after
midnight. Waves calm to 2 feet.
.WEDNESDAY...Northwest winds 5 to 15 knots backing west. Waves
calm to 2 feet.
.THURSDAY...Southwest winds 10 to 20 knots backing south. Waves
calm to 2 feet.

$$

LSZ264-160800-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
1001 PM EDT Sat Aug 15 2026

.REST OF TONIGHT...East winds 10 to 20 knots becoming southeast
5 to 15 knots after midnight, then veering northwest late.
Showers likely and a chance of thunderstorms. Waves 1 to 3 feet
subsiding to calm to 2 feet.
.SUNDAY...Northwest winds 10 to 20 knots backing west late. A
slight chance of showers through early afternoon. Waves building
to 1 to 3 feet, then subsiding to calm to 2 feet.
.SUNDAY NIGHT...West winds 5 to 15 knots veering northwest after
midnight, then backing west late. Waves calm to 2 feet.
.MONDAY...West winds 10 to 20 knots backing southwest by mid
afternoon. Waves building to 1 to 3 feet.
.MONDAY NIGHT...Southwest winds 10 to 20 knots becoming west 5 to
15 knots after midnight. A chance of showers. Waves building to
2 to 4 feet, then subsiding to calm to 2 feet.
.TUESDAY...West winds 5 to 15 knots. Waves calm to 2 feet.
.TUESDAY NIGHT...West winds 5 to 15 knots veering northwest after
midnight. Waves calm to 2 feet.
.WEDNESDAY...Northwest winds 5 to 15 knots backing west. Waves
calm to 2 feet.
.THURSDAY...Southwest winds 5 to 15 knots backing south. Waves
calm to 2 feet.

$$

LSZ265-160800-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1001 PM EDT Sat Aug 15 2026

.REST OF TONIGHT...Southeast winds 10 to 20 knots veering
southwest late. Showers likely and a slight chance of
thunderstorms. Waves 1 to 3 feet subsiding to calm to 2 feet.
.SUNDAY...Northwest winds 15 to 25 knots increasing to 20 to
30 knots in the afternoon. A slight chance of showers through
early afternoon. Waves building to 2 to 4 feet.
.SUNDAY NIGHT...Northwest winds 15 to 25 knots diminishing to
10 to 20 knots after midnight, then backing west late. Waves
subsiding to calm to 2 feet.
.MONDAY...West winds 10 to 20 knots diminishing to 5 to 15 knots
by mid afternoon. Waves calm to 2 feet.
.MONDAY NIGHT...South winds 10 to 20 knots becoming west 15 to
25 knots after midnight. A chance of showers after midnight.
Waves calm to 2 feet.
.TUESDAY...West winds 15 to 25 knots diminishing to 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots veering northwest
after midnight. Waves calm to 2 feet.
.WEDNESDAY...Northwest winds 10 to 20 knots backing west. Waves
calm to 2 feet.
.THURSDAY...East winds 5 to 15 knots becoming south 10 to
20 knots. Waves calm to 2 feet.

$$

LSZ266-160800-
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 Sat Aug 15 2026

.REST OF TONIGHT...Southeast winds 10 to 20 knots veering south
after midnight. A chance of showers by midnight. A chance of
thunderstorms. Showers likely after midnight. Waves 1 to 3 feet
subsiding to calm to 2 feet.
.SUNDAY...Northwest winds 15 to 25 knots increasing to 20 to
30 knots in the afternoon. A slight chance of showers through
early afternoon. Waves building to 3 to 5 feet occasionally to
7 feet.
.SUNDAY NIGHT...Northwest winds 15 to 25 knots diminishing to
10 to 20 knots after midnight. Waves subsiding to calm to 2 feet.
.MONDAY...West winds 5 to 15 knots. Waves calm to 2 feet.
.MONDAY NIGHT...South winds 5 to 15 knots becoming southwest
15 to 25 knots after midnight. A slight chance of showers after
midnight. Waves calm to 2 feet.
.TUESDAY...West winds 10 to 20 knots. Waves building to 1 to
3 feet, then subsiding to calm to 2 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots veering northwest
after midnight. Waves calm to 2 feet.
.WEDNESDAY...Northwest winds 5 to 15 knots. Waves calm to 2 feet.
.THURSDAY...Southwest winds 5 to 15 knots backing south. Waves
calm to 2 feet.

$$

LSZ267-160800-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1001 PM EDT Sat Aug 15 2026

.REST OF TONIGHT...Southeast winds 10 to 20 knots veering south
late. A chance of showers. A chance of thunderstorms after
midnight. Waves calm to 2 feet building to 1 to 3 feet, then
subsiding to calm to 2 feet.
.SUNDAY...Southwest winds 10 to 20 knots becoming northwest 15 to
25 knots in the afternoon, then increasing to 20 to 30 knots
late. A chance of showers and a slight chance of thunderstorms
through early afternoon. Waves building to 3 to 5 feet
occasionally to 7 feet.
.SUNDAY NIGHT...Northwest winds 15 to 25 knots diminishing to
10 to 20 knots after midnight. Waves subsiding to 1 to 3 feet.
.MONDAY...West winds 5 to 15 knots. Waves subsiding to calm to
2 feet.
.MONDAY NIGHT...South winds 5 to 15 knots increasing to 10 to
20 knots after midnight. A slight chance of showers after
midnight. Waves calm to 2 feet.
.TUESDAY...West winds 10 to 20 knots. A chance of showers. Waves
building to 1 to 3 feet, then subsiding to calm to 2 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots veering northwest
after midnight. Waves calm to 2 feet.
.WEDNESDAY...Northwest winds 10 to 20 knots diminishing to 5 to
15 knots. Waves calm to 2 feet.
.THURSDAY...West winds 5 to 15 knots backing south. Waves calm to
2 feet.

$$

LSZ261-160800-
MAFOR 1603/
Superior West 11100 11800 11610 11620 11720 11620 12610. A chance
of showers overnight. Waves 1 to 3 feet.

Superior North Central 11326 11416 11610 13720 11620 11710. A
chance of thunderstorms overnight. Waves 1 to 3 feet.

Superior South Central 12426 11510 11630 12740 12730. Waves 1 to
3 feet overnight. Waves 1 to 3 feet building to 2 to 4 feet
Sunday. Waves 2 to 4 feet subsiding to 1 to 3 feet Sunday
evening.

Superior East 11320 12426 11510 11720 13730. A chance of
thunderstorms overnight and Sunday morning. Waves 1 to 3 feet
overnight. Waves 2 to 4 feet Sunday. Waves 3 to 5 feet Sunday
evening.

$$

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