492
FZUS63 KMQT 120802
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
401 AM 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 30.4 inch high pressure shifts off the Atlantic Coast
today, with a 29.5 inch low simultaneously organizing over the
Northern Plains. The low over the Northern Plains deepens to 29.3
inches tonight and Tuesday morning as heights fall across Lake
Superior. Expect troughing of around 29.8 inches to develop over
Lake Superior by Tuesday evening as the low gradually weakens while
moving through Manitoba and northern Ontario. Troughing over Lake
Superior progressively deepens to 29.1 inches by Thursday night as
another low forms over the Northern Plains during the middle of this
week before lifting into northern Ontario by Friday. Ridging
replaces outgoing low pressure Sat/Sun.


LSZ162-122000-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
401 AM EDT Mon May 12 2025 /301 AM CDT Mon May 12 2025/

.EARLY THIS MORNING...Southwest winds 10 to 20 knots. Waves 2 to
4 feet subsiding to 1 to 3 feet.
.TODAY...Southwest winds 10 to 20 knots backing southeast late.
Waves subsiding to calm to 2 feet.
.TONIGHT...South winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. Waves calm to 2 feet.
.TUESDAY...South winds 5 to 15 knots becoming east 10 to 20 knots
in the afternoon. Waves calm to 2 feet.
.TUESDAY NIGHT...Northeast winds 5 to 15 knots veering east after
midnight. Waves calm to 2 feet.
.WEDNESDAY...East winds 5 to 15 knots becoming northeast 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...Northeast winds 10 to 20 knots. Waves building
to 1 to 3 feet, then subsiding to calm to 2 feet.
.THURSDAY...East winds 15 to 25 knots becoming south 10 to
20 knots. A chance of showers. Showers likely. Waves building to
3 to 5 feet occasionally to 7 feet, then subsiding to 1 to
3 feet.
.FRIDAY...Southwest winds 15 to 25 knots veering west. A chance
of rain showers, then rain showers likely. Waves building to 2 to
4 feet, then subsiding to 1 to 3 feet.

$$

LSZ263-122000-
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 AM EDT Mon May 12 2025

.EARLY THIS MORNING...Southwest winds 10 to 20 knots. Waves 2 to
4 feet.
.TODAY...Southwest winds 10 to 20 knots becoming south 5 to
15 knots in the afternoon, then backing southeast late. Waves
subsiding to calm to 2 feet.
.TONIGHT...South winds 5 to 15 knots. Waves 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.
.TUESDAY NIGHT...Southeast winds 5 to 15 knots veering south
after midnight. Waves building to 1 to 3 feet, then subsiding to
calm to 2 feet.
.WEDNESDAY...Southeast winds 5 to 15 knots backing northeast by
mid afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...East winds 5 to 15 knots. Waves building to
1 to 3 feet.
.THURSDAY...East winds 10 to 20 knots veering south. A chance of
rain showers. Rain showers likely. Waves building 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 2 to 4 feet.

$$

LSZ264-122000-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
401 AM EDT Mon May 12 2025

.EARLY THIS MORNING...Southwest winds 10 to 20 knots. Waves 2 to
4 feet.
.TODAY...South winds 10 to 20 knots diminishing to 5 to 15 knots
in the afternoon, then backing southeast late. Waves subsiding to
1 to 3 feet.
.TONIGHT...South winds 10 to 20 knots diminishing to 5 to
15 knots late. Waves building to 3 to 5 feet occasionally to
7 feet, then subsiding to 1 to 3 feet.
.TUESDAY...South winds 5 to 15 knots backing southeast 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 1 to 3 feet.
.WEDNESDAY...Southeast winds 5 to 15 knots backing east by mid
afternoon. Waves subsiding to calm to 2 feet, then building to
1 to 3 feet.
.WEDNESDAY NIGHT...East winds 5 to 15 knots veering southeast
after midnight. Waves building to 2 to 4 feet.
.THURSDAY...Southeast winds 10 to 20 knots. A chance of rain
showers, then rain showers likely and a chance of thunderstorms.
Waves building 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 2 to 4 feet, then building to
3 to 5 feet occasionally to 7 feet.

$$

LSZ265-122000-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
401 AM EDT Mon May 12 2025

.EARLY THIS MORNING...Southwest winds 10 to 20 knots. Waves 1 to
3 feet.
.TODAY...South winds 5 to 15 knots becoming southeast 10 to
20 knots in the afternoon. Waves subsiding to calm to 2 feet,
then building to 2 to 4 feet.
.TONIGHT...South winds 15 to 25 knots diminishing to 10 to
20 knots after midnight. Waves subsiding to calm to 2 feet.
.TUESDAY...South winds 10 to 20 knots backing southeast in the
afternoon, then increasing to 15 to 25 knots late. Waves building
to 1 to 3 feet.
.TUESDAY NIGHT...Southeast winds 10 to 20 knots diminishing to
5 to 15 knots after midnight. 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 building
to 1 to 3 feet, then subsiding to calm to 2 feet.
.THURSDAY...Southeast winds 10 to 20 knots increasing to 15 to
25 knots. A chance of showers, then showers likely. Waves
building to 2 to 4 feet.
.FRIDAY...Southwest winds 10 to 20 knots becoming west 15 to
25 knots. A chance of rain showers. Waves subsiding to calm to
2 feet.

$$

LSZ266-122000-
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 AM EDT Mon May 12 2025

.EARLY THIS MORNING...South winds 10 to 20 knots. Waves 2 to
4 feet.
.TODAY...South winds 10 to 20 knots backing southeast in the
afternoon, then increasing to 15 to 25 knots late. Waves
subsiding to 1 to 3 feet, then building to 2 to 4 feet.
.TONIGHT...South winds 15 to 25 knots diminishing to 10 to
20 knots after midnight. Waves building to 3 to 5 feet
occasionally to 7 feet, then subsiding to 2 to 4 feet.
.TUESDAY...South winds 10 to 20 knots backing southeast 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 veering south
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 1 to
3 feet.
.THURSDAY...Southeast winds 10 to 20 knots increasing to 15 to
25 knots. A chance of showers, then showers likely and a chance
of thunderstorms. Waves building to 3 to 6 feet occasionally to
8 feet.
.FRIDAY...South winds 15 to 25 knots veering west. A chance of
rain showers. Waves subsiding to 2 to 4 feet.

$$

LSZ267-122000-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
401 AM EDT Mon May 12 2025

.EARLY THIS MORNING...South winds 15 to 25 knots. Waves 2 to
4 feet.
.TODAY...Southeast winds 10 to 20 knots becoming south 15 to
25 knots late. Waves subsiding to 1 to 3 feet.
.TONIGHT...South winds 10 to 20 knots. Waves subsiding to calm to
2 feet.
.TUESDAY...Southeast winds 10 to 20 knots. Waves building to 1 to
3 feet.
.TUESDAY NIGHT...Southeast winds 10 to 20 knots. Waves subsiding
to calm to 2 feet.
.WEDNESDAY...Southeast winds 10 to 20 knots. Waves building to
1 to 3 feet.
.WEDNESDAY NIGHT...Southeast winds 10 to 20 knots. Waves 1 to
3 feet.
.THURSDAY...Southeast winds 15 to 25 knots. Showers and a chance
of thunderstorms. Waves building to 3 to 5 feet occasionally to
7 feet, then subsiding to 2 to 4 feet.
.FRIDAY...South winds 10 to 20 knots veering southwest. A chance
of rain showers. Waves subsiding to 1 to 3 feet.

$$

LSZ261-121400-
MAFOR 1209/
Superior West 11530 11520 12410 11310 13410. Waves 2 to 4 feet
subsiding to 1 to 3 feet today. Waves 1 to 2 feet tonight.

Superior North Central 11520 11420 11410 11310 11320 13420. Waves
2 to 4 feet subsiding to 1 to 3 feet today. Waves 1 to 3 feet
building to 2 to 4 feet tonight.

Superior South Central 11520 11410 11310 11320 11330 12420 11410.
Waves 1 to 3 feet today. Waves 2 to 4 feet subsiding to 1 to 3
feet tonight.

Superior East 11430 11410 11310 12320 13420. 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