National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FZUS63 KMQT 181402
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1002 AM EDT Thu Apr 18 2024

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 broad area of low pressure is centered over the
Ontario/Manitoba border at 29.7 inches this morning. This broad
area of low pressure slowly moves over northern Ontario today and
into James Bay Friday night into Saturday, deepening to 29.3
inches. Meanwhile, a 30.4 inch high pressure ridge builds
southeast into the Northern Plains extending weak 30.0 inch
ridging across western Lake Superior. Ridging over the lake builds
to 30.1 inches on Saturday and weakens to 30.0 inches Sunday.
Troughing near 29.8 inches begins to develop over the Northern
Plains and pushes into western Lake Superior on Monday.


LSZ162-182215-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1002 AM EDT Thu Apr 18 2024 /902 AM CDT Thu Apr 18 2024/

.REST OF TODAY...Southwest winds 10 to 20 knots increasing to
15 to 25 knots in the afternoon. Waves 1 to 3 feet building to
3 to 5 feet occasionally to 7 feet.
.TONIGHT...West winds 15 to 25 knots increasing to 20 to 30 knots
late. Waves subsiding to 3 to 6 feet occasionally to 8 feet.
.FRIDAY...West winds 20 to 30 knots. Waves building to 5 to
8 feet occasionally to 10 feet.
.FRIDAY NIGHT...West winds 20 to 30 knots. Waves subsiding to
3 to 5 feet occasionally to 7 feet.
.SATURDAY...Northwest winds 20 to 30 knots becoming west 15 to
25 knots by mid afternoon. Waves 3 to 5 feet occasionally to
7 feet.
.SATURDAY NIGHT...West winds 15 to 25 knots. Waves subsiding to
1 to 3 feet, then building to 2 to 4 feet.
.SUNDAY...West winds 15 to 25 knots diminishing to 10 to
20 knots. Waves subsiding to calm to 2 feet.
.MONDAY...East winds 10 to 20 knots becoming northeast 15 to
25 knots. A chance of rain showers. Waves building to 1 to
3 feet.

$$

LSZ263-182215-
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-
1002 AM EDT Thu Apr 18 2024

.REST OF TODAY...Southwest winds 5 to 15 knots increasing to
15 to 25 knots in the afternoon, then veering west late. Waves
1 to 3 feet building to 3 to 5 feet occasionally to 7 feet.
.TONIGHT...West winds 15 to 25 knots. Waves subsiding to 3 to
5 feet occasionally to 7 feet, then building to 4 to 7 feet
occasionally to 9 feet.
.FRIDAY...West winds 20 to 30 knots with a few gale force gusts
to 35 knots possible. Waves building to 7 to 11 feet occasionally
to 14 feet.
.FRIDAY NIGHT...West winds 20 to 30 knots. A slight chance of
snow showers after midnight. Waves subsiding to 4 to 7 feet
occasionally to 9 feet.
.SATURDAY...Northwest winds 15 to 25 knots becoming west 20 to
30 knots by mid afternoon. Waves subsiding to 3 to 6 feet
occasionally to 8 feet, then building to 4 to 7 feet occasionally
to 9 feet.
.SATURDAY NIGHT...West winds 15 to 25 knots. Waves subsiding to
3 to 6 feet occasionally to 8 feet.
.SUNDAY...West winds 15 to 25 knots becoming southwest 10 to
20 knots. Waves subsiding to calm to 2 feet.
.MONDAY...South winds 5 to 15 knots becoming east 10 to 20 knots.
A chance of rain showers. Waves building to 1 to 3 feet.

$$

LSZ264-182215-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
1002 AM EDT Thu Apr 18 2024

.REST OF TODAY...West winds 5 to 15 knots becoming southwest
10 to 20 knots in the afternoon, then increasing to 15 to
25 knots late. Waves 1 to 3 feet building to 2 to 4 feet.
.TONIGHT...West winds 10 to 20 knots increasing to 15 to 25 knots
after midnight. Waves building to 4 to 7 feet occasionally to
9 feet.
.FRIDAY...West winds 20 to 30 knots with a few gale force gusts
to 35 knots possible. Waves building to 8 to 11 feet occasionally
to 14 feet.
.FRIDAY NIGHT...West winds 20 to 30 knots. A slight chance of
snow showers after midnight. Waves subsiding to 4 to 7 feet
occasionally to 9 feet.
.SATURDAY...Northwest winds 15 to 25 knots becoming west 20 to
30 knots by mid afternoon. Waves subsiding to 3 to 6 feet
occasionally to 8 feet, then building to 4 to 7 feet occasionally
to 9 feet.
.SATURDAY NIGHT...West winds 20 to 30 knots diminishing to 15 to
25 knots after midnight. Waves subsiding to 3 to 6 feet
occasionally to 8 feet.
.SUNDAY...West winds 20 to 30 knots becoming northwest 10 to
20 knots. Waves subsiding to 1 to 3 feet.
.MONDAY...Southwest winds 5 to 15 knots becoming east 10 to
20 knots. A chance of rain showers. Waves subsiding to calm to
2 feet, then building to 1 to 3 feet.

$$

LSZ265-182215-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1002 AM EDT Thu Apr 18 2024

.REST OF TODAY...West winds 10 to 20 knots diminishing to 5 to
15 knots in the afternoon, then backing south late. A slight
chance of rain showers by mid afternoon. Waves 1 to 3 feet
subsiding to calm to 2 feet.
.TONIGHT...Southwest winds 5 to 15 knots becoming west 10 to
20 knots after midnight, then increasing to 15 to 25 knots late.
A slight chance of rain showers through midnight. Waves building
to 2 to 4 feet.
.FRIDAY...West winds 20 to 30 knots. Waves building to 4 to
7 feet occasionally to 9 feet.
.FRIDAY NIGHT...West winds 20 to 30 knots. A slight chance of
rain and snow showers after midnight. Waves subsiding to 3 to
6 feet occasionally to 8 feet.
.SATURDAY...West winds 20 to 30 knots diminishing to 15 to
25 knots by mid afternoon. Waves subsiding to 2 to 4 feet.
.SATURDAY NIGHT...West winds 15 to 25 knots increasing to 20 to
30 knots after midnight. Waves subsiding to 1 to 3 feet, then
building to 2 to 4 feet.
.SUNDAY...West winds 20 to 30 knots becoming southwest 10 to
20 knots. Waves subsiding to calm to 2 feet.
.MONDAY...Northeast winds 10 to 20 knots veering east. A chance
of rain showers. Waves calm to 2 feet.

$$

LSZ266-182215-
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-
1002 AM EDT Thu Apr 18 2024

.REST OF TODAY...West winds 10 to 20 knots diminishing to 5 to
15 knots in the afternoon, then becoming south 10 to 20 knots
late. A slight chance of rain showers by mid afternoon. Waves
3 to 5 feet occasionally to 7 feet subsiding to 1 to 3 feet.
.TONIGHT...Southwest winds 10 to 20 knots veering west after
midnight, then increasing to 15 to 25 knots late. A chance of
rain showers. Waves building to 3 to 6 feet occasionally to
8 feet.
.FRIDAY...West winds 20 to 30 knots with a few gale force gusts
to 35 knots possible. Waves building to 8 to 11 feet occasionally
to 14 feet.
.FRIDAY NIGHT...West winds 20 to 30 knots with a few gale force
gusts to 35 knots possible. A slight chance of rain and snow
showers after midnight. Waves subsiding to 6 to 9 feet
occasionally to 11 feet.
.SATURDAY...Northwest winds 20 to 30 knots backing west by mid
afternoon. Waves subsiding to 4 to 7 feet occasionally to 9 feet.
.SATURDAY NIGHT...West winds 20 to 30 knots. Waves subsiding to
3 to 6 feet occasionally to 8 feet.
.SUNDAY...West winds 20 to 30 knots becoming northwest 10 to
20 knots. Waves building to 4 to 7 feet occasionally to 9 feet,
then subsiding to 1 to 3 feet.
.MONDAY...Southwest winds 10 to 20 knots becoming east 15 to
25 knots. A chance of rain showers. Waves subsiding to calm to
2 feet.

$$

LSZ267-182215-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1002 AM EDT Thu Apr 18 2024

.REST OF TODAY...West winds 15 to 25 knots diminishing to 10 to
20 knots in the afternoon, then becoming southeast 5 to 15 knots
late. Waves 3 to 5 feet occasionally to 7 feet subsiding to calm
to 2 feet.
.TONIGHT...South winds 5 to 15 knots becoming west 10 to 20 knots
after midnight. A chance of rain showers. Waves building to 2 to
4 feet.
.FRIDAY...West winds 15 to 25 knots increasing to 30 knots with a
few gale force gusts to 35 knots possible in the afternoon. Waves
building to 7 to 10 feet occasionally to 13 feet.
.FRIDAY NIGHT...West winds 20 to 30 knots with a few gale force
gusts to 35 knots possible. A slight chance of rain and snow
showers. Waves subsiding to 6 to 9 feet occasionally to 11 feet.
.SATURDAY...West winds 20 to 30 knots with a few gale force gusts
to 35 knots possible. Waves building to 7 to 10 feet occasionally
to 13 feet, then subsiding to 5 to 8 feet occasionally to 10
feet.
.SATURDAY NIGHT...West winds 20 to 30 knots. Waves subsiding to
3 to 6 feet occasionally to 8 feet.
.SUNDAY...West winds 20 to 30 knots diminishing to 15 to
25 knots. Waves subsiding to 1 to 3 feet.
.MONDAY...Southwest winds 10 to 20 knots backing east. A chance
of rain showers. Waves subsiding to calm to 2 feet.

$$
LSZ261-182215-
MAFOR 1815/
Superior West 13530 13630 12640. Waves 2 to 4 feet building to 3
to 5 feet this afternoon. Waves 3 to 6 feet tonight. Waves 3 to 6
feet building to 4 to 7 feet Friday morning.

Superior North Central 11510 11520 12530 13630 11640. Waves 2 to
3 feet this afternoon. Waves 2 to 4 feet building to 3 to 6 feet
tonight. Waves 5 to 8 feet Friday morning.

Superior South Central 11610 11500 11400 11510 11520 12630 11640.
A chance of rain showers this evening. Waves 1 to 3 feet this
afternoon. Waves 1 to 3 feet building to 2 to 4 feet tonight.
Waves 3 to 5 feet Friday morning.

Superior East 11620 11510 12400 11510 11620 12630. A chance of
rain showers tonight. Waves 3 to 5 feet subsiding to 2 to 3 feet
this afternoon. Waves 1 to 3 feet building to 2 to 4 feet
tonight. Waves 3 to 6 feet Friday morning.

$$

LC

Experimental modernized open lake forecast is available online at
weather.gov/mqt/glftable

Graphical marine forecasts are available online at:
weather.gov/greatlakes