531
FZUS63 KMQT 130201
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1001 PM EDT Mon May 12 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...A 29.3 inch low over the Northern Plains lifts
northeast tonight before moving into Manitoba and eventually
northern Ontario Tuesday and Tuesday evening as it weakens. This
keeps heights steady over Lake Superior until Tuesday evening, when
troughing deepens to around 29.8 inches. The troughing over Lake
Superior progressively deepens to 29.3 inches by Thursday night as
another low forms over the Northern Plains during the middle of this
week before lifting into northern Ontario Thursday night or Friday.
Ridging moves into Lake Superior behind the low this weekend as a
30.4 inch high pressure drops into northern Manitoba by Sunday.


LSZ162-130800-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1001 PM EDT Mon May 12 2025 /901 PM CDT Mon May 12 2025/

.REST OF TONIGHT...Northeast winds 5 to 15 knots veering east
after midnight. Waves calm to 2 feet.
.TUESDAY...East winds 5 to 15 knots increasing to 10 to 20 knots
in the afternoon. Waves calm to 2 feet.
.TUESDAY NIGHT...Northeast winds 10 to 20 knots diminishing to
5 to 15 knots after midnight, then veering east late. Waves calm
to 2 feet.
.WEDNESDAY...East winds 5 to 15 knots becoming northeast 10 to
20 knots by mid afternoon. A slight chance of showers by mid
afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...Northeast winds 10 to 20 knots. A slight
chance of showers. Waves building to 1 to 3 feet, then subsiding
to calm to 2 feet.
.THURSDAY...Northeast winds 10 to 20 knots increasing to 15 to
25 knots by mid afternoon. Showers likely by mid afternoon. Waves
building to 3 to 6 feet occasionally to 8 feet.
.THURSDAY NIGHT...East winds 15 to 25 knots veering south after
midnight. Showers through midnight. A chance of showers after
midnight. Waves subsiding to 2 to 4 feet.
.FRIDAY...Southwest winds 15 to 25 knots veering west. Rain
showers likely. Waves building to 3 to 5 feet occasionally to
7 feet, then subsiding to 1 to 3 feet.
.SATURDAY...West winds 15 to 25 knots becoming northwest 10 to
20 knots. A chance of rain showers. Waves subsiding to calm to
2 feet.

$$

LSZ263-130800-
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-
1001 PM EDT Mon May 12 2025

.REST OF TONIGHT...South winds 5 to 15 knots increasing to 10 to
20 knots after midnight. Waves calm to 2 feet building to 1 to
3 feet.
.TUESDAY...South winds 5 to 15 knots backing east in the
afternoon. Waves subsiding to calm to 2 feet, then building to
1 to 3 feet.
.TUESDAY NIGHT...Southeast winds 10 to 20 knots becoming south
5 to 15 knots after midnight. Waves building to 2 to 4 feet, then
subsiding to calm to 2 feet.
.WEDNESDAY...East winds 5 to 15 knots backing northeast by mid
afternoon. A slight chance of rain showers by mid afternoon.
Waves calm to 2 feet.
.WEDNESDAY NIGHT...East winds 5 to 15 knots. A slight chance of
thunderstorms through midnight. A slight chance of rain showers.
Waves building to 1 to 3 feet.
.THURSDAY...East winds 10 to 20 knots increasing to 15 to
25 knots by mid afternoon. A chance of rain showers. Waves
building to 3 to 6 feet occasionally to 8 feet.
.THURSDAY NIGHT...Southeast winds 20 to 30 knots becoming south
15 to 25 knots after midnight. Showers and a chance of
thunderstorms through midnight, then a chance of showers after
midnight. Waves building to 4 to 7 feet occasionally to 9 feet,
then subsiding to 3 to 6 feet occasionally to 8 feet.
.FRIDAY...Southwest winds 10 to 20 knots veering west. A chance
of rain showers. Waves subsiding to 3 to 5 feet occasionally to
7 feet.
.SATURDAY...West winds 10 to 20 knots veering northwest. A chance
of rain showers. Waves subsiding to 1 to 3 feet.

$$

LSZ264-130800-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
1001 PM EDT Mon May 12 2025

.REST OF TONIGHT...South winds 15 to 25 knots diminishing to
10 to 20 knots late. Waves 3 to 6 feet occasionally to 8 feet
subsiding to 2 to 4 feet.
.TUESDAY...South winds 5 to 15 knots backing southeast in the
afternoon, then increasing to 10 to 20 knots late. Waves
subsiding to 1 to 3 feet.
.TUESDAY NIGHT...Southeast winds 10 to 20 knots veering south
after midnight, then becoming southeast 5 to 15 knots late. Waves
building to 3 to 5 feet occasionally to 7 feet, then subsiding to
1 to 3 feet.
.WEDNESDAY...Southeast winds 5 to 15 knots backing east by mid
afternoon. Waves subsiding to calm to 2 feet.
.WEDNESDAY NIGHT...East winds 5 to 15 knots veering southeast
after midnight. Waves building to 1 to 3 feet.
.THURSDAY...Southeast winds 10 to 20 knots becoming east 15 to
25 knots by mid afternoon. Waves building to 3 to 6 feet
occasionally to 8 feet.
.THURSDAY NIGHT...Southeast winds 15 to 25 knots diminishing to
10 to 20 knots after midnight. A chance of thunderstorms through
midnight. Showers. Waves building to 4 to 7 feet occasionally to
9 feet.
.FRIDAY...South winds 10 to 20 knots veering west. A chance of
rain showers. Waves subsiding to 3 to 5 feet occasionally to
7 feet.
.SATURDAY...West winds 10 to 20 knots veering northwest. A chance
of rain showers. Waves subsiding to 2 to 4 feet.

$$

LSZ265-130800-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1001 PM EDT Mon May 12 2025

.REST OF TONIGHT...South winds 15 to 25 knots diminishing to
10 to 20 knots after midnight. Waves 3 to 5 feet occasionally to
7 feet subsiding to 1 to 3 feet.
.TUESDAY...Southeast winds 5 to 15 knots increasing to 15 to
25 knots. Waves subsiding to calm to 2 feet, then building to
2 to 4 feet.
.TUESDAY NIGHT...Southeast winds 15 to 25 knots diminishing to
5 to 15 knots. Waves subsiding to calm to 2 feet.
.WEDNESDAY...Southeast winds 5 to 15 knots becoming east 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...Southeast winds 10 to 20 knots. Waves calm to
2 feet.
.THURSDAY...Southeast winds 10 to 20 knots becoming east 15 to
25 knots by mid afternoon. Waves building to 2 to 4 feet.
.THURSDAY NIGHT...Southeast winds 15 to 25 knots veering south
after midnight. Showers likely and a chance of thunderstorms
through midnight, then a chance of showers after midnight. Waves
building to 3 to 5 feet occasionally to 7 feet, then subsiding to
2 to 4 feet.
.FRIDAY...South winds 15 to 25 knots becoming west 10 to
20 knots. A chance of rain showers. Waves subsiding to calm to
2 feet.
.SATURDAY...West winds 15 to 25 knots veering northwest. A chance
of rain showers. Waves building to 1 to 3 feet.

$$

LSZ266-130800-
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-
1001 PM EDT Mon May 12 2025

.REST OF TONIGHT...South winds 15 to 25 knots diminishing to
10 to 20 knots late. Waves 3 to 6 feet occasionally to 8 feet
subsiding to 2 to 4 feet.
.TUESDAY...South winds 10 to 20 knots backing southeast in the
afternoon. Waves subsiding to 1 to 3 feet.
.TUESDAY NIGHT...Southeast winds 10 to 20 knots diminishing to
5 to 15 knots late. Waves building to 2 to 4 feet, then subsiding
to 1 to 3 feet.
.WEDNESDAY...Southeast winds 5 to 15 knots increasing to 10 to
20 knots by mid afternoon. Waves 1 to 3 feet.
.WEDNESDAY NIGHT...Southeast winds 10 to 20 knots. Waves 1 to
3 feet.
.THURSDAY...Southeast winds 10 to 20 knots becoming east 15 to
25 knots by mid afternoon. Waves building to 3 to 5 feet
occasionally to 7 feet.
.THURSDAY NIGHT...Southeast winds 15 to 25 knots. A chance of
thunderstorms through midnight. Showers. Waves building to 4 to
7 feet occasionally to 9 feet, then subsiding to 3 to 6 feet
occasionally to 8 feet.
.FRIDAY...South winds 15 to 25 knots becoming southwest 10 to
20 knots. A chance of rain showers. Waves subsiding to 2 to
4 feet, then building to 3 to 5 feet occasionally to 7 feet.
.SATURDAY...West winds 15 to 25 knots veering northwest. A chance
of rain showers. Waves 3 to 5 feet occasionally to 7 feet.

$$

LSZ267-130800-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1001 PM EDT Mon May 12 2025

.REST OF TONIGHT...South winds 10 to 20 knots backing southeast
after midnight, then increasing to 15 to 25 knots late. Waves
1 to 3 feet subsiding to calm to 2 feet, then building to 1 to
3 feet.
.TUESDAY...Southeast winds 10 to 20 knots. Waves subsiding to
calm to 2 feet, then building to 1 to 3 feet.
.TUESDAY NIGHT...Southeast winds 15 to 25 knots diminishing to
10 to 20 knots after midnight. Waves building to 2 to 4 feet,
then subsiding to 1 to 3 feet.
.WEDNESDAY...Southeast winds 10 to 20 knots. Waves subsiding to
calm to 2 feet, then building to 1 to 3 feet.
.WEDNESDAY NIGHT...Southeast winds 10 to 20 knots. Waves
subsiding to calm to 2 feet.
.THURSDAY...Southeast winds 10 to 20 knots increasing to 15 to
25 knots by mid afternoon. Waves building to 3 to 5 feet
occasionally to 7 feet.
.THURSDAY NIGHT...Southeast winds 15 to 25 knots. A chance of
thunderstorms through midnight. Showers. Waves building to 3 to
6 feet occasionally to 8 feet.
.FRIDAY...South winds 15 to 25 knots diminishing to 10 to
20 knots. A chance of rain showers. Waves subsiding to 2 to
4 feet.
.SATURDAY...West winds 15 to 25 knots veering northwest. A chance
of rain showers. Waves building to 3 to 5 feet occasionally to
7 feet.

$$

LSZ261-130800-
MAFOR 1303/
Superior West 11310 12320 11310 11200 13210. Waves 1 to 3 feet.

Superior North Central 11440 13420 14320. Waves 3 to 6 feet
overnight. Waves 2 to 4 feet subsiding to 1 to 3 feet Tuesday.
Waves 2 to 4 feet Tuesday evening.

Superior South Central 11430 13420 12320 11330 11320. Waves 3 to
5 feet subsiding to 1 to 3 feet overnight. Waves 1 to 3 feet
Tuesday. Waves 2 to 4 feet Tuesday evening.

Superior East 11430 15320 11320. Waves 2 to 4 feet.

$$

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