399
FZUS63 KMQT 160801
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
401 AM EDT Sun Aug 16 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...

This morning, a 29.9 inch trough is over the lake associated with a
29.8 inch low over far northern Ontario. By tonight, the low will
deepen to 29.7 inches as 30.0 inch high pressure expands over the
Northern Plains. By Monday afternoon, the high will build to 30.1
inches over Iowa as the low deepens to 29.6 inches over northeast
Quebec. Meanwhile, a 29.5 inch low develops over western Hudson Bay.
By Tuesday morning, the low will expand across much of Hudson Bay
while the hgih weakens to 30.0 inches and sags south of the Great
Lakes. As the low reaches northwest Quebec at 29.6 inches Tuesday
night, another 30.0 inch high settles over North Dakota. This high
moves over Lake Superior Wednesday evening, expanding to cover much
of the Great Lakes by Thursday evening. Friday into the weekend, a
low pressure of around 29.87 inches will transit across northern
Ontario.



LSZ162-162000-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
401 AM EDT Sun Aug 16 2026 /301 AM CDT Sun Aug 16 2026/

.EARLY THIS MORNING...West winds 5 to 15 knots. Waves calm to
2 feet.
.TODAY...West winds 10 to 20 knots. Waves calm to 2 feet.
.TONIGHT...West winds 10 to 20 knots becoming northwest 5 to
15 knots after midnight. Waves calm to 2 feet.
.MONDAY...West winds 5 to 15 knots becoming southwest 10 to
20 knots in the afternoon. A slight chance of showers 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...West winds 5 to 15 knots veering northwest after
midnight. 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 becoming southwest 10 to
20 knots. A chance of showers. Waves calm to 2 feet.

$$

LSZ263-162000-
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-
401 AM EDT Sun Aug 16 2026

.EARLY THIS MORNING...West winds 5 to 15 knots. A slight chance
of showers. Waves calm to 2 feet.
.TODAY...West winds 10 to 20 knots. A slight chance of showers
through early afternoon. Waves building to 1 to 3 feet, then
subsiding to calm to 2 feet.
.TONIGHT...Northwest winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. Waves calm to 2 feet.
.MONDAY...West winds 5 to 15 knots becoming southwest 15 to
25 knots in the afternoon. A chance of showers 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. Waves calm to 2 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots becoming northwest
5 to 15 knots after midnight. Waves calm to 2 feet.
.WEDNESDAY...Southwest winds 5 to 15 knots. Waves calm to 2 feet.
.THURSDAY...Southwest winds 10 to 20 knots becoming south 15 to
25 knots. A chance of showers. Waves building to 1 to 3 feet.

$$

LSZ264-162000-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
401 AM EDT Sun Aug 16 2026

.EARLY THIS MORNING...West winds 5 to 15 knots. A chance of
showers. Waves calm to 2 feet.
.TODAY...West winds 10 to 20 knots veering northwest late. Waves
calm to 2 feet.
.TONIGHT...Northwest winds 5 to 15 knots. Waves calm to 2 feet.
.MONDAY...West winds 5 to 15 knots becoming southwest 10 to
20 knots in the afternoon. A chance of showers 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 5 to 15 knots increasing to 10 to 20 knots
by mid afternoon. Waves calm to 2 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots becoming northwest
5 to 15 knots 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 becoming south 10 to
20 knots. A chance of showers. Waves building to 1 to 3 feet.

$$

LSZ265-162000-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
401 AM EDT Sun Aug 16 2026

.EARLY THIS MORNING...Southwest winds 10 to 20 knots. Showers
likely and a slight chance of thunderstorms. Waves calm to
2 feet.
.TODAY...West winds 15 to 25 knots becoming northwest 20 to
30 knots in the afternoon. A slight chance of showers through
early afternoon. Waves building to 2 to 4 feet, then subsiding to
1 to 3 feet.
.TONIGHT...Northwest winds 10 to 20 knots backing west late.
Waves subsiding to calm to 2 feet.
.MONDAY...West winds 10 to 20 knots diminishing to 5 to 15 knots
late. 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. Waves calm to
2 feet.
.TUESDAY...West winds 15 to 25 knots veering northwest by mid
afternoon. Waves building to 1 to 3 feet, then subsiding to calm
to 2 feet.
.TUESDAY NIGHT...West winds 10 to 20 knots. Waves calm to 2 feet.
.WEDNESDAY...Northwest winds 10 to 20 knots becoming west 5 to
15 knots. Waves calm to 2 feet.
.THURSDAY...Southeast winds 5 to 15 knots becoming south 10 to
20 knots. Waves building to 1 to 3 feet.

$$

LSZ266-162000-
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-
401 AM EDT Sun Aug 16 2026

.EARLY THIS MORNING...Southwest winds 10 to 20 knots. Showers
likely and a chance of thunderstorms. Waves 1 to 3 feet subsiding
to calm to 2 feet.
.TODAY...Northwest winds 15 to 25 knots increasing to 20 to
30 knots in the afternoon, then diminishing to 15 to 25 knots
late. A chance of showers through early afternoon. Waves building
to 3 to 5 feet occasionally to 7 feet, then subsiding to 2 to
4 feet.
.TONIGHT...Northwest winds 15 to 25 knots diminishing to 10 to
20 knots after midnight. Waves subsiding to calm to 2 feet.
.MONDAY...Northwest winds 5 to 15 knots backing southwest late.
Waves calm to 2 feet.
.MONDAY NIGHT...South winds 5 to 15 knots becoming southwest
15 to 25 knots after midnight. A chance of showers. Waves calm to
2 feet.
.TUESDAY...West winds 15 to 25 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 backing west. Waves
calm to 2 feet.
.THURSDAY...West winds 5 to 15 knots becoming south 15 to
25 knots. Waves building to 1 to 3 feet.

$$

LSZ267-162000-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
401 AM EDT Sun Aug 16 2026

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

$$

LSZ261-161400-
MAFOR 1609/
Superior West 11610 13620 12610 11710 11700. Waves 2 feet or
less.

Superior North Central 11610 11720 11620 12720 11710 12700. A
chance of showers early this morning. Waves 1 to 2 feet.

Superior South Central 11526 11630 12740 12730 11720 11710. Waves
1 to 3 feet building to 2 to 4 feet today. Waves 1 to 3 feet
tonight.

Superior East 11416 11520 11720 13730 11720 11710. A chance of
thunderstorms this morning. Waves 2 to 4 feet today. Waves 3 to 5
feet subsiding to 2 to 4 feet tonight.

$$

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