191
FZUS63 KMQT 201953
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
353 PM EDT Fri Sep 20 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...As a 29.3 inch low continues to track northeast to
Hudson Bay today, the associated trough will fill to 29.7 inches
as it moves over western Lake Superior. This trough will then
dissipate, allowing weak 29.9 inch ridging to anchor over the
Upper Great Lakes on Saturday morning. A new low pressure of 29.6
inches over southern Manitoba Saturday morning will then track
across far northern Ontario Saturday afternoon and night. Its
associated 29.9 inch trough will sweep across Lake Superior during
Saturday night and Sunday morning. In its wake, 30.1 inch high
pressure will build from the Northern Plains into northern Ontario
during Sunday and Monday. Also on Monday, a 29.7 inch low
pressure will track northeast to southern Wisconsin. 30.0 inch
high pressure builds over the Lower MS Valley Tuesday, building to
30.1 inches Wednesday.



LSZ162-210400-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
353 PM EDT Fri Sep 20 2024 /253 PM CDT Fri Sep 20 2024/

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

$$

LSZ263-210400-
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 Fri Sep 20 2024

.LATE THIS AFTERNOON...West winds 15 to 25 knots. Waves 2 to
4 feet.
.TONIGHT...West winds 10 to 20 knots becoming southwest 5 to
15 knots after midnight. Waves subsiding to calm to 2 feet.
.SATURDAY...Southwest winds 5 to 15 knots backing southeast in
the afternoon. A chance of showers. A slight chance of
thunderstorms by mid afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...West winds 10 to 20 knots veering northwest
after midnight, then increasing to 15 to 25 knots late. A chance
of showers and a slight chance of thunderstorms. Waves building
to 3 to 5 feet occasionally to 7 feet.
.SUNDAY...Northwest winds 10 to 20 knots. Waves subsiding to calm
to 2 feet.
.SUNDAY NIGHT...Northwest winds 5 to 15 knots veering north after
midnight. Waves calm to 2 feet.
.MONDAY...North winds 5 to 15 knots veering northeast by mid
afternoon. Waves calm to 2 feet.
.MONDAY NIGHT...Southeast winds 5 to 15 knots. Waves calm to
2 feet.
.TUESDAY...Southwest winds 5 to 15 knots veering west. Waves calm
to 2 feet.
.WEDNESDAY...West winds 5 to 15 knots. Waves calm to 2 feet.

$$

LSZ264-210400-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
353 PM EDT Fri Sep 20 2024

.LATE THIS AFTERNOON...Southwest winds 10 to 20 knots. Waves 1 to
3 feet building to 2 to 4 feet.
.TONIGHT...Southwest winds 10 to 20 knots becoming west 5 to
15 knots after midnight, then backing southwest late. Waves
subsiding to calm to 2 feet.
.SATURDAY...Southwest winds 5 to 15 knots backing southeast in
the afternoon. A chance of showers by mid afternoon. Waves
building to 1 to 3 feet.
.SATURDAY NIGHT...South winds 10 to 20 knots becoming northwest
15 to 25 knots after midnight. A chance of showers and a slight
chance of thunderstorms. Waves building to 3 to 6 feet
occasionally to 8 feet.
.SUNDAY...Northwest winds 15 to 25 knots diminishing to 10 to
20 knots by mid afternoon. Waves subsiding to 1 to 3 feet.
.SUNDAY NIGHT...North winds 5 to 15 knots. Waves subsiding to
calm to 2 feet.
.MONDAY...North winds 5 to 15 knots. Waves calm to 2 feet.
.MONDAY NIGHT...East winds 5 to 15 knots veering southeast after
midnight. Waves calm to 2 feet.
.TUESDAY...East winds 5 to 15 knots veering west. Waves calm to
2 feet.
.WEDNESDAY...Northwest winds 5 to 15 knots backing west. Waves
calm to 2 feet.

$$

LSZ265-210400-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
353 PM EDT Fri Sep 20 2024

.LATE THIS AFTERNOON...South winds 5 to 15 knots. Waves calm to
2 feet.
.TONIGHT...Southwest winds 5 to 15 knots. Waves calm to 2 feet.
.SATURDAY...Southwest winds 5 to 15 knots backing southeast in
the afternoon, then increasing to 10 to 20 knots late. A chance
of showers by mid afternoon. Waves building to 1 to 3 feet.
.SATURDAY NIGHT...South winds 10 to 20 knots veering west after
midnight, then becoming northwest 15 to 25 knots late. A chance
of showers and a slight chance of thunderstorms. Waves building
to 2 to 4 feet, then subsiding to 1 to 3 feet.
.SUNDAY...Northwest winds 20 to 30 knots diminishing to 15 to
25 knots by mid afternoon. A slight chance of thunderstorms
through early afternoon. A slight chance of showers. Waves
building to 3 to 5 feet occasionally to 7 feet, then subsiding to
1 to 3 feet.
.SUNDAY NIGHT...Northwest winds 10 to 20 knots veering north
after midnight. Waves 1 to 3 feet.
.MONDAY...North winds 10 to 20 knots veering northeast by mid
afternoon. Waves subsiding to calm to 2 feet.
.MONDAY NIGHT...Northeast winds 5 to 15 knots veering east after
midnight. Waves calm to 2 feet.
.TUESDAY...Northeast winds 5 to 15 knots becoming west 10 to
20 knots. Waves calm to 2 feet.
.WEDNESDAY...Northwest winds 10 to 20 knots diminishing to 5 to
15 knots. Waves calm to 2 feet.

$$

LSZ266-210400-
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 Fri Sep 20 2024

.LATE THIS AFTERNOON...South winds 5 to 15 knots. Waves 1 to
3 feet.
.TONIGHT...South winds 5 to 15 knots veering west late. A slight
chance of showers and thunderstorms through midnight. Patchy fog
after midnight. Waves subsiding to calm to 2 feet.
.SATURDAY...Southwest winds 5 to 15 knots backing southeast late.
A slight chance of showers by mid afternoon. Waves building to
1 to 3 feet.
.SATURDAY NIGHT...South winds 10 to 20 knots veering southwest
after midnight, then becoming northwest 15 to 25 knots late. A
chance of showers and thunderstorms. Waves building to 3 to
6 feet occasionally to 8 feet.
.SUNDAY...Northwest winds 20 to 30 knots. A chance of showers and
a slight chance of thunderstorms. Waves building to 4 to 7 feet
occasionally to 9 feet, then subsiding to 3 to 6 feet
occasionally to 8 feet.
.SUNDAY NIGHT...North winds 15 to 25 knots. Waves subsiding to
2 to 4 feet.
.MONDAY...North winds 10 to 20 knots. Waves subsiding to calm to
2 feet.
.MONDAY NIGHT...Northeast winds 5 to 15 knots veering east after
midnight. Waves calm to 2 feet.
.TUESDAY...Northeast winds 5 to 15 knots backing northwest. Waves
calm to 2 feet.
.WEDNESDAY...Northwest winds 10 to 20 knots becoming north 5 to
15 knots. Waves calm to 2 feet.

$$

LSZ267-210400-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
353 PM EDT Fri Sep 20 2024

.LATE THIS AFTERNOON...Southeast winds 10 to 20 knots. A slight
chance of showers and thunderstorms. Waves 1 to 3 feet subsiding
to calm to 2 feet.
.TONIGHT...South winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. A slight chance of thunderstorms through
midnight. A slight chance of showers. Areas of fog after
midnight. Waves calm to 2 feet.
.SATURDAY...South winds 5 to 15 knots veering southwest in the
afternoon, then backing southeast late. Waves calm to 2 feet.
.SATURDAY NIGHT...South winds 10 to 20 knots veering west late. A
chance of showers. A slight chance of thunderstorms after
midnight. Waves building to 2 to 4 feet.
.SUNDAY...Northwest winds 15 to 25 knots increasing to 20 to
30 knots by mid afternoon. Showers likely through early
afternoon. A slight chance of thunderstorms. A chance of showers
by mid afternoon. Waves building to 4 to 7 feet occasionally to
9 feet, then subsiding to 3 to 6 feet occasionally to 8 feet.
.SUNDAY NIGHT...Northwest winds 15 to 25 knots veering north
after midnight. A chance of showers. Waves subsiding to 2 to
4 feet.
.MONDAY...North winds 10 to 20 knots. Waves subsiding to calm to
2 feet.
.MONDAY NIGHT...North winds 10 to 20 knots veering east after
midnight. Waves calm to 2 feet.
.TUESDAY...Northeast winds 10 to 20 knots backing north. Waves
calm to 2 feet.
.WEDNESDAY...Northwest winds 10 to 20 knots veering north. Waves
calm to 2 feet.

$$

LSZ261-210400-
MAFOR 2021/
Superior West 11530 11520 11510 13500 11300 11310. A chance of
showers Saturday afternoon. Waves 2 to 4 feet subsiding to 1 to 3
feet tonight. Waves 1 foot or less Saturday.

Superior North Central 11520 12510 11600 11500 12400 11310. Waves
1 to 3 feet building to 2 to 4 feet tonight. Waves 1 to 2 feet
Saturday.

Superior South Central 11400 14500 11500 11400 11310. Waves 2
feet or less.

Superior East 11310 11410 12500 11504 11400 11500 11400. Waves 1
to 3 feet subsiding to 1 foot or less tonight. Waves 1 foot or
less Saturday.

$$

LC

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

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