270
FZUS63 KMQT 232002
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
401 PM EDT Thu Apr 23 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 rather tight longitudinal pressure gradient sits across Lake
Superior this afternoon, with 30.0 inches at Whitefish Bay and 29.7
inches near Duluth, thanks to ridging over James Bay and a 29.2 inch
low sitting just north of North Dakota in Canada. Between now and
Friday evening, the James Bay high persists while the Canadian low
swings north into Manitoba, sending troughing of around 29.6 inches
across Lake Superior. Late Friday and into Saturday, the parent low
weakens considerably as remnant troughing moves south and 30.0 inch
ridging builds over Lake Superior by late Saturday. This ridge
builds to 30.1 inches by late Sunday and persists into early Monday.
Meanwhile, a 29.3 inch Colorado Low develops, moving towards the
Upper Midwest by early Monday, causing pressure over Lake Superior
to fall rapidly toward 29.7 inches by mid-Monday. Lake Superior
pressure continues to fall as this 29.3 inch low reaches MN/WI by
late Monday and Lake Superior by early Tuesday, causing pressure
over the lake to remain low near 29.3 throughout Tuesday. This low
lifts north into Ontario Wednesday morning, and Lake Superior
pressures increase to 29.8 inches by Wednesday midday.


LSZ162-240800-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
401 PM EDT Thu Apr 23 2026 /301 PM CDT Thu Apr 23 2026/

.LATE THIS AFTERNOON...Northeast winds 10 to 20 knots. A chance
of showers and thunderstorms. Waves 3 to 5 feet occasionally to
7 feet.
.TONIGHT...Northeast winds 10 to 20 knots veering east after
midnight, then backing northeast late. Rain showers and a chance
of thunderstorms. Waves building to 3 to 6 feet occasionally to
8 feet.
.FRIDAY...West winds 10 to 20 knots diminishing to 5 to 15 knots
late. A chance of rain showers. Waves subsiding to 2 to 4 feet.
.FRIDAY NIGHT...West winds 5 to 15 knots veering north after
midnight, then backing northwest late. Waves subsiding to calm to
2 feet.
.SATURDAY...Northwest winds 5 to 15 knots veering east by mid
afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...East winds 5 to 15 knots backing northeast
after midnight. Waves calm to 2 feet.
.SUNDAY...Northeast winds 5 to 15 knots increasing to 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.SUNDAY NIGHT...East winds 10 to 20 knots becoming northeast
15 to 25 knots after midnight. Waves building to 3 to 5 feet
occasionally to 7 feet.
.MONDAY...East winds 20 to 30 knots backing northeast. Rain
showers likely. Waves building to 5 to 8 feet occasionally to
10 feet, then subsiding to 3 to 6 feet occasionally to 8 feet.
.TUESDAY...West winds 20 to 30 knots diminishing to 15 to
25 knots. A chance of rain showers. Waves subsiding to 3 to
6 feet occasionally to 8 feet.

$$

LSZ263-240800-
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 Thu Apr 23 2026

.LATE THIS AFTERNOON...East winds 15 to 25 knots. A slight chance
of showers and thunderstorms. Waves 4 to 8 feet occasionally to
10 feet.
.TONIGHT...Southeast winds 20 to 30 knots. Rain showers and a
chance of thunderstorms. Waves building to 7 to 10 feet
occasionally to 13 feet.
.FRIDAY...West winds 20 to 30 knots diminishing to 10 to
20 knots. Rain showers and a slight chance of thunderstorms
through early afternoon, then a chance of rain showers by mid
afternoon. Waves subsiding to 3 to 6 feet occasionally to 8 feet.
.FRIDAY NIGHT...Northwest winds 10 to 20 knots becoming north
5 to 15 knots after midnight, then backing northwest late. Waves
subsiding to calm to 2 feet.
.SATURDAY...Northwest winds 5 to 15 knots backing south by mid
afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...East winds 5 to 15 knots diminishing to less
than 10 knots after midnight. Waves calm to 2 feet.
.SUNDAY...East winds 5 to 15 knots backing northeast by mid
afternoon. Waves calm to 2 feet.
.SUNDAY NIGHT...East winds 5 to 15 knots increasing to 10 to
20 knots after midnight. Waves building to 1 to 3 feet.
.MONDAY...East winds 20 to 30 knots increasing to gales to
35 knots. A chance of rain showers, then rain showers likely.
Waves building to 6 to 9 feet occasionally to 11 feet.
.TUESDAY...West gales to 35 knots diminishing to 15 to 25 knots.
A chance of rain showers. Waves subsiding to 4 to 8 feet
occasionally to 10 feet.

$$

LSZ264-240800-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
401 PM EDT Thu Apr 23 2026

...GALE WARNING IN EFFECT FROM 8 PM EDT THIS EVENING THROUGH
FRIDAY AFTERNOON...

.LATE THIS AFTERNOON...East winds 20 to 30 knots. Waves 5 to
9 feet occasionally to 11 feet.
.TONIGHT...Southeast gales to 35 knots. A chance of rain showers
through midnight. A chance of thunderstorms. Rain showers likely
after midnight. Waves building to 8 to 11 feet occasionally to
14 feet.
.FRIDAY...Southeast gales to 35 knots diminishing to 20 to
30 knots in the afternoon, then becoming west 15 to 25 knots
late. Rain showers and a slight chance of thunderstorms through
early afternoon, then a chance of rain showers by mid afternoon.
Waves subsiding to 5 to 8 feet occasionally to 10 feet.
.FRIDAY NIGHT...Northwest winds 5 to 15 knots veering north after
midnight. A slight chance of rain showers through midnight. Waves
subsiding to 1 to 3 feet.
.SATURDAY...Northwest winds 5 to 15 knots. Waves subsiding to
calm to 2 feet.
.SATURDAY NIGHT...East winds less than 10 knots. Waves calm to
2 feet.
.SUNDAY...East winds 5 to 15 knots. Waves calm to 2 feet.
.SUNDAY NIGHT...East winds 5 to 15 knots. Waves calm to 2 feet.
.MONDAY...East gales to 40 knots. A chance of rain showers, then
rain showers likely. Waves building to 7 to 10 feet occasionally
to 13 feet.
.TUESDAY...West gales to 40 knots diminishing to 20 to 30 knots.
A chance of rain showers. Waves subsiding to 2 to 4 feet.

$$

LSZ265-240800-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
401 PM EDT Thu Apr 23 2026

.LATE THIS AFTERNOON...Southeast winds to 30 knots with a few
gale force gusts to 35 knots possible. Waves 3 to 6 feet
occasionally to 8 feet building to 4 to 7 feet occasionally to
9 feet.
.TONIGHT...Southeast winds 20 to 30 knots. A chance of showers
and thunderstorms. Waves 4 to 7 feet occasionally to 9 feet.
.FRIDAY...Southeast winds to 30 knots with a few gale force gusts
to 35 knots possible diminishing to 20 to 30 knots in the
afternoon, then becoming west 15 to 25 knots late. Rain showers
and a slight chance of thunderstorms through early afternoon,
then a chance of rain showers by mid afternoon. Waves building to
5 to 8 feet occasionally to 10 feet, then subsiding to 3 to
6 feet occasionally to 8 feet.
.FRIDAY NIGHT...West winds 10 to 20 knots veering northwest after
midnight. Waves subsiding to calm to 2 feet.
.SATURDAY...Northwest winds 10 to 20 knots becoming north 5 to
15 knots by mid afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...East winds 5 to 15 knots veering southeast
after midnight. Waves calm to 2 feet.
.SUNDAY...Southeast winds 5 to 15 knots becoming east 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.SUNDAY NIGHT...East winds 10 to 20 knots veering southeast after
midnight. Waves calm to 2 feet.
.MONDAY...East gales to 35 knots becoming southeast gales to
40 knots. A chance of rain showers, then rain showers likely.
Waves building to 7 to 11 feet occasionally to 14 feet.
.TUESDAY...West gales to 40 knots. A chance of rain showers.
Waves subsiding to 2 to 4 feet.

$$

LSZ266-240800-
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 Thu Apr 23 2026

...GALE WARNING IN EFFECT FROM 8 PM EDT THIS EVENING THROUGH
FRIDAY AFTERNOON...

.LATE THIS AFTERNOON...Southeast winds 20 to 30 knots. Waves 4 to
8 feet occasionally to 10 feet.
.TONIGHT...Southeast gales to 35 knots. A chance of rain showers
and a slight chance of thunderstorms. Waves building to 8 to
11 feet occasionally to 14 feet.
.FRIDAY...Southeast gales to 35 knots diminishing to 20 to
30 knots late. A chance of rain showers through early afternoon.
A slight chance of thunderstorms. Rain showers by mid afternoon.
Waves subsiding to 4 to 7 feet occasionally to 9 feet.
.FRIDAY NIGHT...West winds 10 to 20 knots veering northwest after
midnight. A chance of rain showers. Waves subsiding to 1 to
3 feet.
.SATURDAY...Northwest winds 10 to 20 knots becoming north 5 to
15 knots by mid afternoon. Waves subsiding to calm to 2 feet.
.SATURDAY NIGHT...East winds 5 to 15 knots veering southeast
after midnight. Waves calm to 2 feet.
.SUNDAY...Southeast winds 5 to 15 knots backing east by mid
afternoon. Waves calm to 2 feet.
.SUNDAY NIGHT...East winds 5 to 15 knots becoming southeast 10 to
20 knots after midnight. Waves building to 1 to 3 feet.
.MONDAY...East gales to 40 knots veering southeast. A chance of
rain showers, then rain showers likely. Waves building to 7 to
10 feet occasionally to 13 feet.
.TUESDAY...West gales to 40 knots. A chance of rain showers.
Waves subsiding to 6 to 9 feet occasionally to 11 feet, then
building to 7 to 10 feet occasionally to 13 feet.

$$

LSZ267-240800-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
401 PM EDT Thu Apr 23 2026

...GALE WARNING IN EFFECT FROM 8 PM EDT THIS EVENING THROUGH
FRIDAY AFTERNOON...

.LATE THIS AFTERNOON...Southeast winds 20 to 30 knots. Waves 3 to
6 feet occasionally to 8 feet building to 4 to 7 feet
occasionally to 9 feet.
.TONIGHT...Southeast winds 20 to 30 knots increasing to gales to
35 knots after midnight. A slight chance of rain showers after
midnight. Waves subsiding to 3 to 6 feet occasionally to 8 feet,
then building to 5 to 8 feet occasionally to 10 feet.
.FRIDAY...Southeast gales to 40 knots diminishing to 20 to
30 knots late. A slight chance of rain showers through early
afternoon, then rain showers likely and a slight chance of
thunderstorms by mid afternoon. Waves building to 6 to 9 feet
occasionally to 11 feet, then subsiding to 3 to 5 feet
occasionally to 7 feet.
.FRIDAY NIGHT...Southeast winds 10 to 20 knots backing east late.
Rain showers likely through midnight, then a chance of rain
showers after midnight. Waves subsiding to 1 to 3 feet.
.SATURDAY...Southeast winds 10 to 20 knots becoming east 5 to
15 knots by mid afternoon. Waves subsiding to calm to 2 feet.
.SATURDAY NIGHT...East winds 5 to 15 knots veering southeast
after midnight. Waves calm to 2 feet.
.SUNDAY...Southeast winds 5 to 15 knots backing east by mid
afternoon. Waves calm to 2 feet.
.SUNDAY NIGHT...East winds 5 to 15 knots veering southeast after
midnight. Waves calm to 2 feet.
.MONDAY...Southeast gales to 40 knots. Rain showers likely. Waves
building to 5 to 9 feet occasionally to 11 feet.
.TUESDAY...Southwest gales to 35 knots becoming west 20 to
30 knots. Rain showers likely, then a chance of rain showers.
Waves building to 7 to 10 feet occasionally to 13 feet, then
subsiding to 3 to 6 feet occasionally to 8 feet.

$$

LSZ261-240200-
MAFOR 2321/
Superior West 11220 12226 11216 11126 11616 12620. A chance of
thunderstorms tonight. Waves 3 to 6 feet tonight. Waves 2 to 4
feet Friday.

Superior North Central...GALE WARNING IN EFFECT...11240 12350
14356 11440. A chance of thunderstorms tonight. Waves 5 to 8 feet
building to 7 to 11 feet tonight. Waves 7 to 11 feet Friday.

Superior South Central...GALE WARNING IN EFFECT...14340 11340
11350 11346 11436. Waves 5 to 8 feet.

Superior East...GALE WARNING IN EFFECT...11340 15350 11356. Waves
5 to 8 feet tonight. Waves 6 to 10 feet Friday.

$$

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