National Weather Service Marine Forecast FZUS63 KMQT

FZUS63 KMQT 231342
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
942 AM EDT Mon Sep 23 2019

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 29.7 inch trough will exit eastern Lake Superior
later this morning. In its wake, a 29.9 inch high pressure ridge
will cross Lake Superior this afternoon and tonight. The ridge
will shift to the Lower Great Lakes by Tuesday evening as a 29.5
inch trough moves east into Minnesota. As the trough moves across
Lake Superior late Tuesday night and Wednesday morning, low
pressure will develop along the trough and deepen to 29.1 inches
by the time it reaches southern Hudson Bay Wednesday evening. In
its wake, a 29.8 inch high pressure ridge over the Northern Plains
Wednesday night will shift east across the Upper Great Lakes on
Thursday. This weak ridge will be followed by a 29.5 inch low
pressure moving across Lake Superior on Friday.

LSZ162-232145-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
942 AM EDT Mon Sep 23 2019 /842 AM CDT Mon Sep 23 2019/

REST OF TODAY
West winds 5 to 15 knots backing southwest in
the afternoon. Waves calm to 2 feet.

TONIGHT
South winds 5 to 15 knots veering southwest after
midnight. Waves calm to 2 feet.

TUESDAY
Southwest winds 5 to 15 knots. Patchy fog. A slight
chance of showers and thunderstorms by mid afternoon. Waves calm
to 2 feet.

TUESDAY NIGHT
Southwest winds 5 to 15 knots becoming west
10 to 20 knots after midnight. Showers through midnight. A chance
of thunderstorms. A chance of showers after midnight. Waves
building to 1 to 3 feet.

WEDNESDAY
West winds 15 to 25 knots. Waves building to 3 to
5 feet occasionally to 7 feet, then subsiding to 2 to 4 feet.

WEDNESDAY NIGHT
West winds 10 to 20 knots. Waves 2 to 4 feet.

THURSDAY
West winds 10 to 20 knots becoming south 15 to
25 knots. Showers likely. Waves subsiding to calm to 2 feet, then
building to 2 to 4 feet.

FRIDAY
South winds 10 to 20 knots veering west. A chance of
showers. Waves subsiding to calm to 2 feet.

LSZ263-232145-
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-
942 AM EDT Mon Sep 23 2019

REST OF TODAY
West winds 5 to 15 knots backing southwest late.
Waves 1 to 3 feet subsiding to calm to 2 feet.

TONIGHT
South winds 5 to 15 knots veering southwest after
midnight. Waves calm to 2 feet.

TUESDAY
Southwest winds 5 to 15 knots backing south late.
Patchy fog. Waves building to 1 to 3 feet, then subsiding to calm
to 2 feet.

TUESDAY NIGHT
Southwest winds 10 to 20 knots veering west
after midnight. Showers likely and a chance of thunderstorms.
Waves building to 2 to 4 feet.

WEDNESDAY
West winds 15 to 25 knots. Waves building to 4 to
7 feet occasionally to 9 feet.

WEDNESDAY NIGHT
West winds 15 to 25 knots. Waves subsiding to
3 to 6 feet occasionally to 8 feet.

THURSDAY
West winds 15 to 25 knots becoming south 20 to
30 knots. A chance of showers. Waves subsiding to calm to 2 feet,
then building to 2 to 4 feet.

FRIDAY
South winds 15 to 25 knots becoming west 10 to
20 knots. A chance of showers. Waves building to 3 to 6 feet
occasionally to 8 feet, then subsiding to calm to 2 feet.

LSZ264-232145-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
942 AM EDT Mon Sep 23 2019

REST OF TODAY
Northwest winds 5 to 15 knots backing southwest
late. Isolated showers by late morning. Waves 1 to 3 feet
subsiding to calm to 2 feet.

TONIGHT
Southwest winds 5 to 15 knots backing south after
midnight. Waves calm to 2 feet.

TUESDAY
Southwest winds 5 to 15 knots backing south late.
Patchy fog. Waves building to 1 to 3 feet.

TUESDAY NIGHT
South winds 10 to 20 knots veering southwest
after midnight. Showers likely and a chance of thunderstorms.
Waves building to 2 to 4 feet.

WEDNESDAY
West winds 15 to 25 knots increasing to 20 to
30 knots by mid afternoon. A chance of showers. Waves building to
4 to 7 feet occasionally to 9 feet.

WEDNESDAY NIGHT
West winds 15 to 25 knots. Waves 4 to 7 feet
occasionally to 9 feet.

THURSDAY
West winds 15 to 25 knots becoming southwest 20 to
30 knots. A chance of showers. Waves subsiding to 1 to 3 feet,
then building to 3 to 6 feet occasionally to 8 feet.

FRIDAY
South winds 20 to 30 knots becoming west 10 to
20 knots. Showers likely, then a chance of showers. Waves
building to 5 to 8 feet occasionally to 10 feet, then subsiding
to 1 to 3 feet.

LSZ265-232145-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
942 AM EDT Mon Sep 23 2019

REST OF TODAY
Northwest winds 5 to 15 knots increasing to
10 to 20 knots in the afternoon, then becoming west 5 to 15 knots
late. Scattered showers by late morning. Waves 1 to 3 feet
subsiding to calm to 2 feet.

TONIGHT
Southwest winds less than 10 knots becoming south 5 to
15 knots after midnight, then veering southwest late. Waves calm
to 2 feet.

TUESDAY
Southwest winds 5 to 15 knots backing south in the
afternoon, then increasing to 10 to 20 knots late. Waves calm to
2 feet.

TUESDAY NIGHT
South winds 10 to 20 knots becoming southwest
15 to 25 knots after midnight. A chance of showers through
midnight. A chance of thunderstorms. Showers after midnight.
Waves building to 1 to 3 feet, then subsiding to calm to 2 feet.

WEDNESDAY
West winds 20 to 30 knots. A chance of showers.
Waves building to 3 to 6 feet occasionally to 8 feet.

WEDNESDAY NIGHT
West winds 15 to 25 knots increasing to 20 to
30 knots after midnight. Waves 3 to 5 feet occasionally to
7 feet.

THURSDAY
West winds 15 to 25 knots backing south. A chance of
showers. Waves subsiding to calm to 2 feet, then building to 2 to
4 feet.

FRIDAY
South winds 20 to 30 knots becoming west 15 to
25 knots. Showers likely, then a chance of showers. Waves
building to 3 to 6 feet occasionally to 8 feet, then subsiding to
calm to 2 feet.

LSZ266-232145-
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-
942 AM EDT Mon Sep 23 2019

REST OF TODAY
Northwest winds 5 to 15 knots increasing to
10 to 20 knots in the afternoon. Patchy fog by late morning.
Scattered showers by late morning. Waves 2 to 4 feet subsiding to
1 to 3 feet.

TONIGHT
West winds 5 to 15 knots backing south after midnight.
Waves subsiding to calm to 2 feet.

TUESDAY
South winds 5 to 15 knots. Patchy fog. Waves building
to 1 to 3 feet.

TUESDAY NIGHT
South winds 15 to 25 knots. A chance of showers
through midnight. A chance of thunderstorms. Showers after
midnight. Waves building to 3 to 5 feet occasionally to 7 feet.

WEDNESDAY
West winds 15 to 25 knots increasing to 20 to
30 knots by mid afternoon. A chance of showers. Waves building to
5 to 8 feet occasionally to 10 feet.

WEDNESDAY NIGHT
West winds 15 to 25 knots. Waves subsiding to
4 to 8 feet occasionally to 10 feet.

THURSDAY
West winds 15 to 25 knots backing south. A chance of
showers. Waves subsiding to 1 to 3 feet, then building to 3 to
6 feet occasionally to 8 feet.

FRIDAY
South winds 20 to 30 knots becoming west 10 to
20 knots. Showers likely, then a chance of showers. Waves
building to 6 to 9 feet occasionally to 11 feet, then subsiding
to 1 to 3 feet.

LSZ267-232145-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
942 AM EDT Mon Sep 23 2019

REST OF TODAY
Northwest winds 10 to 20 knots diminishing to
5 to 15 knots in the afternoon, then becoming west 10 to 20 knots
late. Widespread fog by late morning. Scattered showers by late
morning. Waves 2 to 4 feet subsiding to 1 to 3 feet.

TONIGHT
Northwest winds 10 to 20 knots becoming west 5 to
15 knots after midnight, then backing southwest late. Waves
subsiding to calm to 2 feet.

TUESDAY
South winds 10 to 20 knots. Patchy fog. Waves building
to 1 to 3 feet.

TUESDAY NIGHT
South winds 15 to 25 knots increasing to 20 to
30 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.

WEDNESDAY
West winds 20 to 30 knots increasing to gales to
35 knots by mid afternoon. Showers likely through early
afternoon, then a chance of showers by mid afternoon. Waves
building to 6 to 9 feet occasionally to 11 feet.

WEDNESDAY NIGHT
West winds 20 to 30 knots. A chance of
showers. Waves subsiding to 4 to 8 feet occasionally to 10 feet.

THURSDAY
West winds 15 to 25 knots backing south. A chance of
showers. Waves subsiding to 1 to 3 feet, then building to 3 to
5 feet occasionally to 7 feet.

FRIDAY
South gales to 35 knots becoming west 15 to 25 knots.
Showers likely. Waves building to 4 to 7 feet occasionally to
9 feet, then subsiding to 1 to 3 feet.

LSZ261-232145-
MAFOR 2315/
Superior West 11600 12500 11400 11500 12510 11520. Waves 2 feet
or less.

Superior North Central 11710 11610 11510 12500 11400 11410 11510.
Waves 1 to 2 feet.

Superior South Central 11720 19726 11710 11610 11600 11500 11400
11510 11500. Waves 1 to 3 feet this afternoon. Waves 2 feet or
less tonight and Tuesday morning.

Superior East 11710 19716 13710 11610 11500 12410. Waves 1 to 3
feet.

JP

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

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