Great Lakes Forecast
Issued by NWS

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FZUS63 KMQT 251958
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
358 PM EDT Sun Sep 25 2022

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...Troughing of 29.7 inches currently prevailing across the
Great Lakes region will deepen to 29.5 inches tonight as it
becomes centered over southern Ontario. Meanwhile, the pressure
gradient over western Lake Superior tightens as 30.1 inch ridging
pushes in from the west through Monday. The trough over southern
Ontario will slowly move into Quebec by early Tuesday, allowing
30.3 inch ridging to build in behind it. The ridging will build to
30.5 inches as the center moves over Lakes Superior on Wednesday.
Ridging will remain in control of the Great Lakes region through
the end of the week as the center of the ridge weakens to 30.4
inches as it moves towards New England.

LSZ162-260400-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
358 PM EDT Sun Sep 25 2022 /258 PM CDT Sun Sep 25 2022/

.LATE THIS AFTERNOON...Northwest winds 20 to 30 knots. Scattered
showers and isolated thunderstorms. Waves 3 to 6 feet
occasionally to 8 feet.
.TONIGHT...Northwest winds to 30 knots with a few gale force
gusts to 35 knots possible diminishing to 20 to 30 knots late.
Scattered thunderstorms through midnight. Scattered showers.
Waves building to 4 to 7 feet occasionally to 9 feet.
.MONDAY...North winds 20 to 30 knots becoming northwest 15 to
25 knots in the afternoon. Waves subsiding to 2 to 4 feet.
.MONDAY NIGHT...North winds 15 to 25 knots. Waves 2 to 4 feet.
.TUESDAY...North winds 15 to 25 knots diminishing to 10 to
20 knots by mid afternoon. Waves subsiding to calm to 2 feet.
.TUESDAY NIGHT...North winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. Waves building to 1 to 3 feet, then
subsiding to calm to 2 feet.
.WEDNESDAY...North winds 5 to 15 knots veering south by mid
afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...South winds 5 to 15 knots veering southwest
after midnight. Waves calm to 2 feet.
.THURSDAY...Southwest winds 10 to 20 knots backing south. Waves
building to 1 to 3 feet.
.FRIDAY...South winds 10 to 20 knots. Waves subsiding to calm to
2 feet.

$$

LSZ263-260400-
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-
358 PM EDT Sun Sep 25 2022

.LATE THIS AFTERNOON...Northwest winds 20 to 30 knots. Scattered
showers and isolated thunderstorms. Waves 3 to 6 feet
occasionally to 8 feet.
.TONIGHT...Northwest winds 20 to 30 knots increasing to 30 knots
with a few gale force gusts to 35 knots possible after midnight,
then veering north late. Scattered thunderstorms through
midnight. Scattered showers. Waves building to 6 to 9 feet
occasionally to 11 feet.
.MONDAY...North winds to 30 knots with a few gale force gusts to
35 knots possible diminishing to 20 to 30 knots in the afternoon.
A chance of showers. Waves subsiding to 4 to 7 feet occasionally
to 9 feet.
.MONDAY NIGHT...North winds 20 to 30 knots. A slight chance of
rain showers. Waves subsiding to 3 to 6 feet occasionally to
8 feet.
.TUESDAY...North winds 15 to 25 knots diminishing to 10 to
20 knots by mid afternoon. A slight chance of rain showers
through early afternoon. Waves subsiding to 3 to 5 feet
occasionally to 7 feet.
.TUESDAY NIGHT...North winds 10 to 20 knots. Waves subsiding to
1 to 3 feet.
.WEDNESDAY...North winds 5 to 15 knots backing southwest by mid
afternoon. Waves subsiding to calm to 2 feet.
.WEDNESDAY NIGHT...Southwest winds 5 to 15 knots increasing to
10 to 20 knots after midnight. Waves calm to 2 feet.
.THURSDAY...Southwest winds 5 to 15 knots becoming south 10 to
20 knots. Waves building to 1 to 3 feet, then subsiding to calm
to 2 feet.
.FRIDAY...South winds 10 to 20 knots. Waves subsiding to calm to
2 feet.

$$

LSZ264-260400-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
358 PM EDT Sun Sep 25 2022

...GALE WARNING IN EFFECT FROM LATE TONIGHT THROUGH MONDAY
MORNING...

.LATE THIS AFTERNOON...Northwest winds 15 to 25 knots. Numerous
showers. Waves 2 to 4 feet building to 3 to 5 feet occasionally
to 7 feet.
.TONIGHT...Northwest winds 20 to 30 knots veering north after
midnight, then increasing to gales to 35 knots late. Isolated
thunderstorms through midnight. Showers. Waves building to 8 to
11 feet occasionally to 14 feet.
.MONDAY...North gales to 35 knots diminishing to 20 to 30 knots
in the afternoon. Showers likely through early afternoon, then a
chance of showers by mid afternoon. Waves subsiding to 6 to
9 feet occasionally to 11 feet.
.MONDAY NIGHT...North winds 20 to 30 knots. A chance of showers.
Waves subsiding to 4 to 7 feet occasionally to 9 feet.
.TUESDAY...North winds 15 to 25 knots diminishing to 10 to
20 knots by mid afternoon. A slight chance of rain showers
through early afternoon. Waves subsiding to 3 to 6 feet
occasionally to 8 feet.
.TUESDAY NIGHT...North winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. Waves subsiding to 2 to 4 feet.
.WEDNESDAY...North winds 5 to 15 knots backing west by mid
afternoon. Waves subsiding to calm to 2 feet.
.WEDNESDAY NIGHT...Southwest winds 5 to 15 knots. Waves calm to
2 feet.
.THURSDAY...Southwest winds 5 to 15 knots backing south. Waves
building to 1 to 3 feet, then subsiding to calm to 2 feet.
.FRIDAY...South winds 5 to 15 knots. Waves subsiding to calm to
2 feet.

$$

LSZ265-260400-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
358 PM EDT Sun Sep 25 2022

...GALE WARNING IN EFFECT MONDAY MORNING...

.LATE THIS AFTERNOON...Northwest winds 15 to 25 knots. Showers.
Waves calm to 2 feet building to 2 to 4 feet.
.TONIGHT...Northwest winds 20 to 30 knots veering north after
midnight, with a few gale force gusts to 35 knots possible late.
Isolated thunderstorms through midnight. Showers. Waves building
to 7 to 10 feet occasionally to 13 feet.
.MONDAY...North gales to 35 knots. A slight chance of
thunderstorms through early afternoon. Showers. Waves 7 to
10 feet occasionally to 13 feet.
.MONDAY NIGHT...North winds 20 to 30 knots. A chance of showers.
Waves subsiding to 5 to 8 feet occasionally to 10 feet.
.TUESDAY...North winds 20 to 30 knots diminishing to 15 to
25 knots by mid afternoon. A chance of showers. Waves subsiding
to 4 to 7 feet occasionally to 9 feet.
.TUESDAY NIGHT...North winds 15 to 25 knots. Waves subsiding to
3 to 5 feet occasionally to 7 feet.
.WEDNESDAY...North winds 10 to 20 knots diminishing to 5 to
15 knots by mid afternoon. Waves subsiding to calm to 2 feet.
.WEDNESDAY NIGHT...Southwest winds 5 to 15 knots. Waves calm to
2 feet.
.THURSDAY...Southwest winds 10 to 20 knots backing south. Waves
calm to 2 feet.
.FRIDAY...South winds 10 to 20 knots. Waves calm to 2 feet.

$$

LSZ266-260400-
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-
358 PM EDT Sun Sep 25 2022

.LATE THIS AFTERNOON...Northwest winds 10 to 20 knots. Numerous
showers. Waves calm to 2 feet building to 2 to 4 feet.
.TONIGHT...North winds 15 to 25 knots increasing to 20 to
30 knots after midnight. Isolated thunderstorms through midnight.
Showers. Waves building to 7 to 10 feet occasionally to 13 feet.
.MONDAY...North winds to 30 knots with a few gale force gusts to
35 knots possible. A slight chance of thunderstorms through early
afternoon. A chance of showers. Waves building to 8 to 11 feet
occasionally to 14 feet.
.MONDAY NIGHT...North winds to 30 knots with a few gale force
gusts to 35 knots possible. Showers likely through midnight, then
a chance of showers after midnight. Waves subsiding to 6 to
9 feet occasionally to 11 feet.
.TUESDAY...North winds 20 to 30 knots. A chance of showers. Waves
subsiding to 5 to 8 feet occasionally to 10 feet.
.TUESDAY NIGHT...North winds 20 to 30 knots diminishing to 15 to
25 knots after midnight. Waves subsiding to 3 to 6 feet
occasionally to 8 feet.
.WEDNESDAY...North winds 10 to 20 knots. Waves subsiding to 1 to
3 feet.
.WEDNESDAY NIGHT...Northwest winds 5 to 15 knots backing
southwest after midnight. Waves subsiding to calm to 2 feet.
.THURSDAY...Southwest winds 10 to 20 knots backing south. Waves
building to 2 to 4 feet, then subsiding to 1 to 3 feet.
.FRIDAY...South winds 10 to 20 knots. Waves 1 to 3 feet.

$$

LSZ267-260400-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
358 PM EDT Sun Sep 25 2022

.LATE THIS AFTERNOON...Northwest winds 15 to 25 knots. Scattered
showers. Waves 1 to 3 feet building to 2 to 4 feet.
.TONIGHT...Northwest winds 10 to 20 knots increasing to 15 to
25 knots after midnight, then veering north late. Numerous
showers. Waves subsiding to 1 to 3 feet, then building to 2 to
4 feet.
.MONDAY...North winds 15 to 25 knots increasing to 30 knots with
a few gale force gusts to 35 knots possible. Showers likely. A
slight chance of thunderstorms. Waves building to 7 to 10 feet
occasionally to 13 feet.
.MONDAY NIGHT...North winds to 30 knots with a few gale force
gusts to 35 knots possible diminishing to 20 to 30 knots late. A
chance of showers through midnight, then showers likely after
midnight. Waves subsiding to 4 to 7 feet occasionally to 9 feet.
.TUESDAY...North winds 20 to 30 knots. A chance of showers. Waves
4 to 7 feet occasionally to 9 feet.
.TUESDAY NIGHT...North winds 15 to 25 knots. Waves subsiding to
3 to 5 feet occasionally to 7 feet.
.WEDNESDAY...North winds 10 to 20 knots backing northwest by mid
afternoon. Waves subsiding to 1 to 3 feet.
.WEDNESDAY NIGHT...Northwest winds 10 to 20 knots becoming west
5 to 15 knots after midnight. Waves subsiding to calm to 2 feet.
.THURSDAY...Southwest winds 5 to 15 knots becoming south 10 to
20 knots. Waves building to 1 to 3 feet.
.FRIDAY...South winds 10 to 20 knots. Waves subsiding to calm to
2 feet.

$$

LSZ261-260400-
MAFOR 2521/
Superior West 12740 19749 13740 11840 12730. Waves 3 to 7 feet.

Superior North Central...GALE WARNING IN EFFECT...11736 11746
12846 12856 12840. Waves 2 to 4 feet building to 7 to 10 feet
tonight. Waves 7 to 11 feet Monday.

Superior South Central...GALE WARNING IN EFFECT...12736 12846
12856 12846. Waves around 2 feet building to 5 to 8 feet tonight.
Waves 7 to 10 feet Monday.

Superior East 11720 19726 11726 11716 11726 11826 11830 12840.
Waves 2 to 4 feet tonight. Waves 3 to 5 feet building to 5 to 8
feet Monday.

$$

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

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


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