839
FZUS63 KMQT 181345
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
945 AM EDT Wed Sep 18 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...A 30.1 inch high pressure ridge extending from New
England back into the Great Lakes region today will reorient from
Quebec into the Great Lakes region for Thursday. Meanwhile, a 29.3
inch low pressure over eastern Montana today will lift into
southern Manitoba on Thursday with its associated 29.6 inch trough
pushing east into western Minnesota. As the low continues to
track northeast to Hudson Bay during Friday, the associated trough
will weaken to 29.8 inches as it reaches western Lake Superior.
This trough will then dissipate, allowing weak 29.9 inch ridging
to setup over the Upper Great Lakes by Saturday morning. A new low
pressure of 29.7 inches over southern Manitoba Saturday morning
will track into far northern Ontario during Saturday night with
its associated 29.9 inch trough sweeping across Lake Superior. In
its wake, 30.2 inch high pressure will build into Ontario on
Sunday.

LSZ162-182145-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
945 AM EDT Wed Sep 18 2024 /845 AM CDT Wed Sep 18 2024/

.REST OF TODAY...South winds 5 to 15 knots increasing to 10 to
20 knots in the afternoon, then backing east late. Waves calm to
2 feet.
.TONIGHT...Southeast winds 10 to 20 knots veering south after
midnight. A slight chance of showers and thunderstorms after
midnight. Waves calm to 2 feet.
.THURSDAY...East winds 10 to 20 knots veering southeast in the
afternoon, then backing east late. A chance of showers and a
slight chance of thunderstorms. Waves calm to 2 feet.
.THURSDAY NIGHT...South winds 10 to 20 knots veering southwest
after midnight. Showers likely through midnight. A chance of
thunderstorms. A chance of showers after midnight. Waves building
to 1 to 3 feet.
.FRIDAY...Southwest winds 10 to 20 knots. Waves subsiding to calm
to 2 feet.
.FRIDAY NIGHT...West winds 5 to 15 knots veering northwest after
midnight. Waves calm to 2 feet.
.SATURDAY...South winds 5 to 15 knots becoming north 10 to
20 knots. A chance of showers. Waves calm to 2 feet.
.SUNDAY...North winds 10 to 20 knots. A chance of showers. Waves
building to 1 to 3 feet.

$$

LSZ263-182145-
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-
945 AM EDT Wed Sep 18 2024

.REST OF TODAY...South winds 5 to 15 knots backing southeast
late. Waves 1 to 3 feet subsiding to calm to 2 feet.
.TONIGHT...Southeast winds 5 to 15 knots veering south after
midnight, then increasing to 10 to 20 knots late. Waves building
to 1 to 3 feet.
.THURSDAY...South winds 10 to 20 knots backing southeast in the
afternoon. A slight chance of showers. A slight chance of
thunderstorms by mid afternoon. Waves subsiding to calm to
2 feet, then building to 1 to 3 feet.
.THURSDAY NIGHT...South winds 10 to 20 knots. Showers likely
through midnight. A chance of thunderstorms. A chance of showers
after midnight. Waves building to 2 to 4 feet, then subsiding to
1 to 3 feet.
.FRIDAY...Southwest winds 5 to 15 knots. Waves subsiding to calm
to 2 feet.
.FRIDAY NIGHT...Southwest winds 5 to 15 knots becoming west less
than 10 knots after midnight. Waves calm to 2 feet.
.SATURDAY...South winds 5 to 15 knots backing east. A chance of
showers. Waves calm to 2 feet.
.SUNDAY...East winds 10 to 20 knots backing north. A chance of
showers. Waves building to 1 to 3 feet.

$$

LSZ264-182145-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
945 AM EDT Wed Sep 18 2024

.REST OF TODAY...South winds 5 to 15 knots backing southeast
late. Waves 1 to 3 feet.
.TONIGHT...Southeast winds 5 to 15 knots veering south after
midnight. Waves building to 2 to 4 feet, then subsiding to 1 to
3 feet.
.THURSDAY...South winds 10 to 20 knots backing southeast in the
afternoon. A slight chance of showers by mid afternoon. Waves
building to 3 to 5 feet occasionally to 7 feet.
.THURSDAY NIGHT...South winds 15 to 25 knots diminishing to 10 to
20 knots after midnight. A chance of showers through midnight. A
chance of thunderstorms. Showers likely after midnight. Waves
building to 3 to 6 feet occasionally to 8 feet, then subsiding to
2 to 4 feet.
.FRIDAY...South winds 5 to 15 knots. A chance of showers and
thunderstorms. Waves subsiding to calm to 2 feet.
.FRIDAY NIGHT...South winds 5 to 15 knots becoming southwest less
than 10 knots after midnight. Waves calm to 2 feet.
.SATURDAY...South winds 5 to 15 knots. A chance of showers. Waves
calm to 2 feet.
.SUNDAY...Southeast winds 10 to 20 knots backing north. A chance
of showers. Waves building to 1 to 3 feet, then subsiding to calm
to 2 feet.

$$

LSZ265-182145-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
945 AM EDT Wed Sep 18 2024

.REST OF TODAY...South winds 10 to 20 knots backing southeast in
the afternoon. Waves calm to 2 feet building to 1 to 3 feet.
.TONIGHT...South 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 late. Waves building to 2 to 4 feet.
.THURSDAY NIGHT...Southeast winds 15 to 25 knots becoming south
10 to 20 knots after midnight. A chance of showers through
midnight. A chance of thunderstorms. Showers likely after
midnight. Waves building to 3 to 5 feet occasionally to 7 feet,
then subsiding to 1 to 3 feet.
.FRIDAY...South winds 10 to 20 knots backing southeast by mid
afternoon. Showers likely through early afternoon. A chance of
thunderstorms. A chance of showers by mid afternoon. Waves
subsiding to calm to 2 feet.
.FRIDAY NIGHT...South winds 5 to 15 knots veering southwest after
midnight. Waves calm to 2 feet.
.SATURDAY...East winds 5 to 15 knots becoming south 10 to
20 knots. A chance of showers. Waves calm to 2 feet.
.SUNDAY...East winds 10 to 20 knots backing north. A chance of
showers. Waves calm to 2 feet.

$$

LSZ266-182145-
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-
945 AM EDT Wed Sep 18 2024

.REST OF TODAY...South winds 10 to 20 knots backing southeast
late. Waves 1 to 3 feet.
.TONIGHT...South winds 10 to 20 knots. Waves building to 2 to
4 feet, then subsiding to 1 to 3 feet.
.THURSDAY...South winds 10 to 20 knots backing southeast in the
afternoon. Waves building to 2 to 4 feet.
.THURSDAY NIGHT...South winds 15 to 25 knots diminishing to 10 to
20 knots after midnight. A chance of showers through midnight. A
chance of thunderstorms. Showers likely after midnight. 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. Showers likely through
early afternoon. A chance of thunderstorms. A chance of showers
by mid afternoon. Waves subsiding to calm to 2 feet.
.FRIDAY NIGHT...South winds 5 to 15 knots. A chance of showers.
Waves calm to 2 feet.
.SATURDAY...South winds 5 to 15 knots increasing to 10 to
20 knots. A chance of showers. Waves calm to 2 feet.
.SUNDAY...Southeast winds 10 to 20 knots backing east. A chance
of showers. Waves building to 1 to 3 feet, then subsiding to calm
to 2 feet.

$$

LSZ267-182145-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
945 AM EDT Wed Sep 18 2024

.REST OF TODAY...South winds 10 to 20 knots backing southeast in
the afternoon. Waves calm to 2 feet.
.TONIGHT...South winds 10 to 15 knots. Waves calm to 2 feet.
.THURSDAY...Southeast winds 10 to 15 knots. Waves calm to 2 feet.
.THURSDAY NIGHT...Southeast winds 10 to 20 knots. A chance of
showers after midnight. Waves building to 1 to 3 feet.
.FRIDAY...Southeast winds 10 to 20 knots. Showers likely. Waves
subsiding to calm to 2 feet.
.FRIDAY NIGHT...Southeast winds 10 to 20 knots diminishing to
5 to 15 knots after midnight. A chance of showers and
thunderstorms. Waves calm to 2 feet.
.SATURDAY...Southeast winds 5 to 15 knots increasing to 10 to
20 knots. A chance of showers. Waves calm to 2 feet.
.SUNDAY...Southeast winds 10 to 20 knots. A chance of showers.
Waves calm to 2 feet.

$$
LSZ261-182145-
MAFOR 1815/
Superior West 11410 13310 13420 11320. Waves 1 to 3 feet.

Superior North Central 11410 13310 11420 12410 11420. Waves 1 to
3 feet.

Superior South Central 11410 12320 14410 11410. Waves 1 to 3
feet.

Superior East 11410 13310 11410 12400 11300. Waves 1 to 2 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