005
FZUS63 KMQT 152001
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
401 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 30.1 inch high over New England will weaken and shift east through
Sunday as a 29.9 inch trough builds over the lake. The associated
low deepens to 29.7 inches as it reaches Quebec Sunday night. Into
Monday, a 30.1 inch high over the Plains weakens to 30.0 inches as
it slides generally south of the Great Lakes Tuesday. Meanwhile
Tuesday, a 29.4 inch low over Hudson Bay extends a 29.8 inch trough
over Lake Superior. Wednesday into Thursday morning, ridging of 30.1
inches moves over the Upper Great Lakes from the Plains. This
ridging shifts east Thursday night into Friday as a 29.9 inch trough
builds over the lake from the west.



LSZ162-160800-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
401 PM EDT Sat Aug 15 2026 /301 PM CDT Sat Aug 15 2026/

.LATE THIS AFTERNOON...Northeast winds 10 to 20 knots. A chance
of showers and a slight chance of thunderstorms. Waves 1 to
3 feet building to 2 to 4 feet.
.TONIGHT...Northeast winds 10 to 20 knots diminishing to 5 to
15 knots after midnight, then backing west late. A chance of
thunderstorms through midnight. A chance of showers. Waves
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 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-
401 PM EDT Sat Aug 15 2026

.LATE THIS AFTERNOON...East winds 10 to 20 knots. A chance of
showers. Waves 1 to 3 feet building to 2 to 4 feet.
.TONIGHT...East winds 10 to 20 knots diminishing to 5 to 15 knots
after midnight, then veering west late. Showers likely through
midnight. A chance of thunderstorms. A slight chance of showers
after midnight. Waves 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 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-
401 PM EDT Sat Aug 15 2026

.LATE THIS AFTERNOON...East winds 10 to 20 knots. A chance of
showers. Waves calm to 2 feet building to 1 to 3 feet.
.TONIGHT...East winds 10 to 20 knots veering southeast after
midnight, then becoming west 5 to 15 knots late. Showers likely
and a slight chance of thunderstorms. Waves 1 to 3 feet.
.SUNDAY...Northwest winds 10 to 20 knots backing west late. A
slight chance of showers through early afternoon. Waves 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-
401 PM EDT Sat Aug 15 2026

.LATE THIS AFTERNOON...East winds 15 to 25 knots. A slight chance
of showers. Waves calm to 2 feet building to 1 to 3 feet.
.TONIGHT...Southeast winds 15 to 25 knots becoming south 10 to
20 knots after midnight. Showers likely and a slight chance of
thunderstorms. Waves 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-
401 PM EDT Sat Aug 15 2026

.LATE THIS AFTERNOON...East winds 10 to 20 knots. A slight chance
of showers. Waves calm to 2 feet.
.TONIGHT...East winds 10 to 20 knots veering south late. A chance
of showers through midnight. A slight chance of thunderstorms.
Showers likely after midnight. Waves building to 1 to 3 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. Waves calm to 2 feet.
.TUESDAY...West winds 10 to 20 knots. 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 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-
401 PM EDT Sat Aug 15 2026

.LATE THIS AFTERNOON...East winds 10 to 20 knots. A slight chance
of showers. Waves calm to 2 feet.
.TONIGHT...East winds 10 to 20 knots becoming southeast 15 to
25 knots after midnight, then becoming south 10 to 20 knots late.
A chance of showers. A chance of thunderstorms after midnight.
Waves building to 1 to 3 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. Waves calm to 2 feet.
.TUESDAY...West winds 10 to 20 knots. A chance of showers. 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 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.

$$

LSZ261-160200-
MAFOR 1521/
Superior West 12120 11110 11800 11610 11620 11720 11620. A chance
of showers, then a chance of showers and thunderstorms early this
evening. Waves 2 to 4 feet tonight. Waves 1 to 3 feet Sunday.

Superior North Central 11220 11226 11326 11426 11610 13720. Waves
1 to 3 feet.

Superior South Central 11220 11320 11326 11426 11520 11630 12740.
Waves 1 to 3 feet tonight. Waves 1 to 3 feet building to 2 to 4
feet Sunday.

Superior East 12210 11320 11326 11426 11510 11720 11730. A chance
of thunderstorms overnight and Sunday morning. Waves 1 to 3 feet
tonight. Waves 2 to 4 feet Sunday.

$$

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