651
FZUS63 KMQT 202005
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
405 PM EDT Thu Jun 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...High pressure of 30.4 inches centered near Isle Royale
will weaken to 30.2 inches as it very slowly drifts southeast
across central and eastern Lake Superior tonight and Friday. On
Saturday, the high will transition to ridging of 30.0 inches
extending from northern Ontario across southern Quebec. Meanwhile,
29.7 low pressure developing over eastern Colorado on Friday will
track northeast to Wisconsin by Saturday evening. The low will
then deepen to 29.5 inches as it passes near the Straits of
Mackinac during Saturday night and reaches southern Quebec during
Sunday. In its wake, 29.9 inch high pressure building into the
Northern Plains on Sunday will settle over the western Great Lakes
region on Monday and then the Appalachians on Tuesday. Back to
the northwest, 29.3 inch low pressure over Manitoba Monday night
will track east toward James Bay on Tuesday, pushing an associated
29.6 inch trough across Lake Superior.

LSZ162-210415-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
405 PM EDT Thu Jun 20 2024 /305 PM CDT Thu Jun 20 2024/

.LATE THIS AFTERNOON...Northeast winds 10 to 20 knots. Waves calm
to 2 feet.
.TONIGHT...Northeast winds 5 to 15 knots. A slight chance of
showers after midnight. Waves calm to 2 feet.
.FRIDAY...East winds 5 to 15 knots backing northeast in the
afternoon. A chance of showers. A slight chance of thunderstorms
by mid afternoon. Waves calm to 2 feet.
.FRIDAY NIGHT...Northeast winds 5 to 15 knots veering east after
midnight, then becoming northeast 10 to 20 knots late. A chance
of showers and a slight chance of thunderstorms. Waves building
to 1 to 3 feet.
.SATURDAY...Northeast winds 10 to 20 knots. Showers likely and a
slight chance of thunderstorms. Waves building to 3 to 5 feet
occasionally to 7 feet, then subsiding to 2 to 4 feet.
.SATURDAY NIGHT...North winds 10 to 20 knots backing west after
midnight. A chance of showers. Waves subsiding to calm to 2 feet.
.SUNDAY...West winds 10 to 20 knots. A chance of showers. Waves
calm to 2 feet.
.SUNDAY NIGHT...West winds 5 to 15 knots. Waves calm to 2 feet.
.MONDAY...Southwest winds 5 to 15 knots increasing to 10 to
20 knots. A chance of showers and thunderstorms. Waves calm to
2 feet.
.TUESDAY...Southwest winds 10 to 20 knots veering northwest.
Waves building to 2 to 4 feet, then subsiding to calm to 2 feet.

$$

LSZ263-210415-
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-
405 PM EDT Thu Jun 20 2024

.LATE THIS AFTERNOON...East winds 5 to 15 knots. Waves calm to
2 feet.
.TONIGHT...East winds 5 to 15 knots diminishing to less than
10 knots after midnight. A slight chance of showers after
midnight. Waves calm to 2 feet.
.FRIDAY...East winds less than 10 knots increasing to 5 to
15 knots in the afternoon. A slight chance of showers. Waves calm
to 2 feet.
.FRIDAY NIGHT...East winds 5 to 15 knots. A chance of showers and
a slight chance of thunderstorms. Waves calm to 2 feet.
.SATURDAY...East winds 10 to 20 knots backing northeast by mid
afternoon. Showers likely and a slight chance of thunderstorms.
Waves building to 2 to 4 feet.
.SATURDAY NIGHT...North winds 5 to 15 knots backing northwest
after midnight. A chance of showers. Waves subsiding to calm to
2 feet.
.SUNDAY...West winds 5 to 15 knots. A chance of showers. Waves
building to 1 to 3 feet.
.SUNDAY NIGHT...West winds 5 to 15 knots. Waves subsiding to calm
to 2 feet.
.MONDAY...Southwest winds 5 to 15 knots becoming south 10 to
20 knots. A chance of showers and thunderstorms. Waves building
to 1 to 3 feet.
.TUESDAY...Southwest winds 10 to 20 knots veering northwest.
Waves building to 2 to 4 feet, then subsiding to calm to 2 feet.

$$

LSZ264-210415-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
405 PM EDT Thu Jun 20 2024

.LATE THIS AFTERNOON...East winds 5 to 15 knots. Waves calm to
2 feet.
.TONIGHT...East winds less than 10 knots. Waves calm to 2 feet.
.FRIDAY...East winds less than 10 knots veering south late. A
slight chance of showers by mid afternoon. Waves calm to 2 feet.
.FRIDAY NIGHT...South winds less than 10 knots backing southeast
after midnight, then becoming east 5 to 15 knots late. A slight
chance of showers. Waves calm to 2 feet.
.SATURDAY...East winds 5 to 15 knots. A chance of showers through
early afternoon, then showers likely and a slight chance of
thunderstorms by mid afternoon. Waves calm to 2 feet.
.SATURDAY NIGHT...Northeast winds 5 to 15 knots backing north
after midnight. A chance of showers. Waves calm to 2 feet.
.SUNDAY...Northwest winds 5 to 15 knots backing west by mid
afternoon. A chance of showers. Waves building to 1 to 3 feet.
.SUNDAY NIGHT...Northwest winds 5 to 15 knots backing west after
midnight. Waves subsiding to calm to 2 feet.
.MONDAY...West winds 5 to 15 knots becoming south 10 to 20 knots.
A chance of showers and thunderstorms. Waves building to 1 to
3 feet.
.TUESDAY...Southwest winds 10 to 20 knots veering northwest.
Waves building to 2 to 4 feet, then subsiding to 1 to 3 feet.

$$

LSZ265-210415-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
405 PM EDT Thu Jun 20 2024

.LATE THIS AFTERNOON...Northeast winds 5 to 15 knots. Waves calm
to 2 feet.
.TONIGHT...East winds 5 to 15 knots diminishing to less than
10 knots after midnight, then backing northeast late. Waves calm
to 2 feet.
.FRIDAY...East winds 5 to 15 knots veering southeast late. A
slight chance of showers. Waves calm to 2 feet.
.FRIDAY NIGHT...Southeast winds 5 to 15 knots backing east late.
A chance of showers. A slight chance of thunderstorms after
midnight. Waves calm to 2 feet.
.SATURDAY...East winds 5 to 15 knots increasing to 10 to 20 knots
by mid afternoon. Showers likely and a slight chance of
thunderstorms. Waves calm to 2 feet.
.SATURDAY NIGHT...North winds 10 to 20 knots backing northwest
after midnight. A chance of showers. Waves calm to 2 feet.
.SUNDAY...Northwest winds 10 to 20 knots. A chance of showers.
Waves calm to 2 feet.
.SUNDAY NIGHT...West winds 10 to 20 knots. Waves calm to 2 feet.
.MONDAY...West winds 10 to 20 knots backing south. A chance of
showers and thunderstorms. Waves calm to 2 feet.
.TUESDAY...West winds 15 to 25 knots becoming northwest 10 to
20 knots. A chance of showers and thunderstorms. Waves calm to
2 feet.

$$

LSZ266-210415-
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-
405 PM EDT Thu Jun 20 2024

.LATE THIS AFTERNOON...North winds 5 to 15 knots. Waves calm to
2 feet.
.TONIGHT...North winds 5 to 15 knots. Waves calm to 2 feet.
.FRIDAY...North winds 5 to 15 knots backing northwest late. A
slight chance of showers by mid afternoon. Waves calm to 2 feet.
.FRIDAY NIGHT...South winds 5 to 15 knots backing east after
midnight. A chance of showers. A slight chance of thunderstorms
after midnight. Waves calm to 2 feet.
.SATURDAY...East winds 5 to 15 knots increasing to 10 to 20 knots
by mid afternoon. Showers likely and a slight chance of
thunderstorms. Waves calm to 2 feet.
.SATURDAY NIGHT...Northeast winds 10 to 20 knots backing north
after midnight. A chance of showers. Waves building to 1 to
3 feet.
.SUNDAY...Northwest winds 10 to 20 knots. A chance of showers.
Waves 1 to 3 feet.
.SUNDAY NIGHT...Northwest winds 10 to 20 knots. Waves subsiding
to calm to 2 feet.
.MONDAY...West winds 10 to 20 knots backing south. A chance of
showers. Waves building to 1 to 3 feet.
.TUESDAY...Southwest winds 10 to 20 knots veering northwest. A
chance of showers. Waves building to 2 to 4 feet, then subsiding
to 1 to 3 feet.

$$

LSZ267-210415-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
405 PM EDT Thu Jun 20 2024

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

$$

LSZ261-210415-
MAFOR 2021/
Superior West 11110 14100 12200 11100. A chance of showers Friday
afternoon. Waves 1 foot or less.

Superior North Central 11200 11100 11200 11300 12200 12300. Waves
1 foot or less.

Superior South Central 15100 11100 11200. Waves 1 foot or less.

Superior East 12810 14800 12700. Waves 1 foot or less.

$$

Rolfson

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

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