818
FZUS63 KMQT 031953
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
353 PM EDT Thu Apr 3 2025

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...29.4 inch low pressure exits just south of James Bay
this evening. Meanwhile 30.1 inch high pressure over southwestern
Minnesota shifts northeast and builds over Lake Superior tonight.
This ridge builds to 30.3 inches Friday morning. Saturday, Lake
Superior is situated between a 30.4 inch high over the Central
Plains and a 29.8 inch low tracking across the Lower Great Lakes.
This low deepens to 29.3 inches over northern Quebec while the
high over the Plains weakens to 30.2 inches Sunday. Monday, a
30.3 inch high will settle from the Canadian Prairie to the
Northern Plains while a 29.6 inch low approaches the Lower Great
Lakes. On Tuesday the high pressure will enable ridging at 30.2
inches of the Upper Great Lakes.


LSZ162-040400-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
353 PM EDT Thu Apr 3 2025 /253 PM CDT Thu Apr 3 2025/

.LATE THIS AFTERNOON...West winds 10 to 20 knots. Waves 2 to
4 feet subsiding to 1 to 3 feet.
.TONIGHT...West winds 5 to 15 knots veering northwest after
midnight. Waves subsiding to calm to 2 feet.
.FRIDAY...East winds 5 to 15 knots. Waves calm to 2 feet.
.FRIDAY NIGHT...East winds 5 to 15 knots backing north after
midnight, then becoming northwest 10 to 20 knots late. A chance
of rain showers. A chance of snow showers after midnight. Waves
calm to 2 feet.
.SATURDAY...Northwest winds 15 to 25 knots backing west by mid
afternoon. A slight chance of snow showers through early
afternoon. Waves building to 1 to 3 feet, then subsiding to calm
to 2 feet.
.SATURDAY NIGHT...West winds 10 to 20 knots. Waves calm to
2 feet.
.SUNDAY...Northwest winds 10 to 20 knots backing west by mid
afternoon. Waves calm to 2 feet.
.SUNDAY NIGHT...North winds 15 to 25 knots. Waves building to
3 to 5 feet occasionally to 7 feet.
.MONDAY...North winds 15 to 25 knots diminishing to 10 to
20 knots. Waves subsiding to calm to 2 feet.
.TUESDAY...Southwest winds 10 to 20 knots backing south. Waves
calm to 2 feet.

$$

LSZ263-040400-
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-
353 PM EDT Thu Apr 3 2025

.LATE THIS AFTERNOON...West winds 15 to 25 knots. Waves 4 to
7 feet occasionally to 9 feet subsiding to 3 to 6 feet
occasionally to 8 feet.
.TONIGHT...West winds 10 to 20 knots diminishing to 5 to 15 knots
after midnight, then veering northwest late. Waves subsiding to
calm to 2 feet.
.FRIDAY...West winds less than 10 knots backing southwest in the
afternoon, then becoming east 5 to 15 knots late. Waves calm to
2 feet.
.FRIDAY NIGHT...East winds 5 to 15 knots backing north after
midnight, then backing northwest late. A chance of rain and snow
showers after midnight. Waves calm to 2 feet.
.SATURDAY...Northwest winds 10 to 20 knots backing west by mid
afternoon. A slight chance of snow showers, possibly mixed with
rain through early afternoon. Waves building to 2 to 4 feet.
.SATURDAY NIGHT...West winds 10 to 20 knots veering northwest
after midnight. Waves 2 to 4 feet.
.SUNDAY...Northwest winds 10 to 20 knots. Waves subsiding to 1 to
3 feet.
.SUNDAY NIGHT...North winds 15 to 25 knots increasing to 20 to
30 knots after midnight. A chance of snow showers. Waves building
to 3 to 6 feet occasionally to 8 feet.
.MONDAY...North winds 20 to 30 knots diminishing to 10 to
20 knots. Waves subsiding to 1 to 3 feet.
.TUESDAY...Northwest winds 10 to 20 knots backing southwest.
Waves subsiding to calm to 2 feet, then building to 1 to 3 feet.

$$

LSZ264-040400-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
353 PM EDT Thu Apr 3 2025

.LATE THIS AFTERNOON...West winds 15 to 25 knots. Waves 4 to
7 feet occasionally to 9 feet.
.TONIGHT...West winds 10 to 20 knots diminishing to 5 to 15 knots
after midnight, then veering northwest late. Waves subsiding to
calm to 2 feet.
.FRIDAY...West winds less than 10 knots backing southwest in the
afternoon, then backing southeast late. Waves calm to 2 feet.
.FRIDAY NIGHT...Southeast winds 5 to 15 knots veering northwest
late. A chance of rain and snow showers after midnight. Waves
calm to 2 feet.
.SATURDAY...Northwest winds 10 to 20 knots. A chance of snow
showers through early afternoon. Waves building to 2 to 4 feet.
.SATURDAY NIGHT...Northwest winds 10 to 20 knots. Waves 2 to
4 feet.
.SUNDAY...Northwest winds 10 to 20 knots. Waves subsiding to 1 to
3 feet.
.SUNDAY NIGHT...North winds 15 to 25 knots increasing to 20 to
30 knots after midnight. Freezing spray after midnight. Waves
building to 3 to 6 feet occasionally to 8 feet.
.MONDAY...North winds 20 to 30 knots diminishing to 15 to
25 knots. Freezing spray. Waves subsiding to 2 to 4 feet.
.TUESDAY...Northwest winds 10 to 20 knots backing southwest.
Waves subsiding to calm to 2 feet, then building to 1 to 3 feet.

$$

LSZ265-040400-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
353 PM EDT Thu Apr 3 2025

.LATE THIS AFTERNOON...West winds 15 to 25 knots. Waves 3 to
6 feet occasionally to 8 feet.
.TONIGHT...West winds 10 to 20 knots diminishing to 5 to 15 knots
late. Waves subsiding to calm to 2 feet.
.FRIDAY...West winds 5 to 15 knots backing east in the afternoon.
Waves calm to 2 feet.
.FRIDAY NIGHT...Southeast winds 5 to 15 knots veering west late.
A slight chance of rain and snow showers after midnight. Waves
calm to 2 feet.
.SATURDAY...Northwest winds 10 to 20 knots increasing to 15 to
25 knots by mid afternoon. A chance of snow showers, possibly
mixed with rain through early afternoon. Waves building to 1 to
3 feet.
.SATURDAY NIGHT...West winds 15 to 25 knots diminishing to 10 to
20 knots after midnight. Waves subsiding to calm to 2 feet.
.SUNDAY...Northwest winds 10 to 20 knots. Waves calm to 2 feet.
.SUNDAY NIGHT...North winds 10 to 20 knots increasing to 15 to
25 knots after midnight. A chance of snow showers. Waves building
to 3 to 5 feet occasionally to 7 feet.
.MONDAY...North winds 20 to 30 knots diminishing to 15 to
25 knots. Waves building to 3 to 6 feet occasionally to 8 feet,
then subsiding to 2 to 4 feet.
.TUESDAY...Northwest winds 10 to 20 knots backing southwest.
Waves subsiding to calm to 2 feet.

$$

LSZ266-040400-
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-
353 PM EDT Thu Apr 3 2025

...GALE WARNING IN EFFECT UNTIL 5 PM EDT THIS AFTERNOON...

.LATE THIS AFTERNOON...West winds 20 to 30 knots with a few gale
force gusts possible to 35 knots early. Waves 8 to 11 feet
occasionally to 14 feet subsiding to 7 to 10 feet occasionally to
13 feet.
.TONIGHT...West winds 15 to 25 knots becoming northwest 10 to
20 knots after midnight, then diminishing to 5 to 15 knots late.
Waves subsiding to 1 to 3 feet.
.FRIDAY...West winds 5 to 15 knots backing south in the
afternoon, then backing east late. Waves subsiding to calm to
2 feet.
.FRIDAY NIGHT...Southeast winds 5 to 15 knots. A slight chance of
rain showers after midnight. Waves calm to 2 feet.
.SATURDAY...Northwest winds 10 to 20 knots increasing to 20 to
30 knots by mid afternoon. A chance of snow showers, possibly
mixed with rain through early afternoon. Waves building to 3 to
6 feet occasionally to 8 feet.
.SATURDAY NIGHT...Northwest winds 15 to 25 knots. Waves subsiding
to 3 to 5 feet occasionally to 7 feet.
.SUNDAY...Northwest winds 15 to 25 knots. Waves subsiding to 2 to
4 feet.
.SUNDAY NIGHT...North winds 15 to 25 knots. A chance of snow
showers. Waves building to 3 to 6 feet occasionally to 8 feet.
.MONDAY...North winds 20 to 30 knots. Freezing spray. Waves
building to 5 to 8 feet occasionally to 10 feet, then subsiding
to 3 to 6 feet occasionally to 8 feet.
.TUESDAY...Northwest winds 15 to 25 knots becoming west 10 to
20 knots. Waves subsiding to 1 to 3 feet.

$$

LSZ267-040400-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
353 PM EDT Thu Apr 3 2025

...GALE WARNING IN EFFECT UNTIL 5 PM EDT THIS AFTERNOON...

.LATE THIS AFTERNOON...West winds to 30 knots with a few gale
force gusts to 35 knots possible early. Waves 9 to 12 feet
occasionally to 15 feet subsiding to 7 to 10 feet occasionally to
13 feet.
.TONIGHT...West winds 15 to 25 knots becoming northwest 10 to
20 knots after midnight, then diminishing to 5 to 15 knots late.
Waves subsiding to 2 to 4 feet.
.FRIDAY...Southwest winds 5 to 15 knots backing south in the
afternoon, then backing east late. Waves subsiding to calm to
2 feet.
.FRIDAY NIGHT...East winds 5 to 15 knots veering southeast after
midnight. Waves calm to 2 feet.
.SATURDAY...West winds 10 to 20 knots becoming northwest 15 to
25 knots by mid afternoon. A slight chance of rain showers
through early afternoon. A slight chance of snow showers. Waves
building to 3 to 6 feet occasionally to 8 feet.
.SATURDAY NIGHT...Northwest winds 20 to 30 knots diminishing to
15 to 25 knots after midnight. Waves subsiding to 3 to 5 feet
occasionally to 7 feet.
.SUNDAY...Northwest winds 15 to 25 knots. Waves subsiding to 2 to
4 feet.
.SUNDAY NIGHT...Northwest winds 15 to 25 knots veering north
after midnight. Waves building to 3 to 5 feet occasionally to
7 feet.
.MONDAY...North winds 20 to 30 knots. Freezing spray. Waves
building to 5 to 8 feet occasionally to 10 feet, then subsiding
to 3 to 6 feet occasionally to 8 feet.
.TUESDAY...Northwest winds 15 to 25 knots diminishing to 10 to
20 knots. Waves subsiding to 1 to 3 feet.

$$

LSZ261-040400-
MAFOR 0321/
Superior West 11620 11610 11600 12700 11600 11300 11200. Waves 1
to 4 feet tonight. Waves 1 foot or less Friday.

Superior North Central 11630 11620 12710 11700 12600 11400. Waves
4 to 7 feet subsiding to 2 to 4 feet tonight. Waves 2 feet or
less Friday.

Superior South Central 12630 12710 12600 11500 11200. Waves 5 to
8 feet subsiding to 1 to 2 feet tonight and Friday.

Superior East 11640 11630 11720 11710 11700 11600 12400. Waves 8
to 12 feet subsiding to 3 to 5 feet tonight. Waves 2 to 4 feet
subsiding to 1 to 2 feet Friday.

$$

JSS

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

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