491
FZUS63 KMQT 201401
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
1001 AM EDT Mon Jul 20 2026

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 low pressure will track into Ontario and deepen to 29.4 inches
tonight with a 29.5 inch trough over Lake Superior. The low will
then push east into Quebec and retrograde to northern Quebec for
midweek. Meanwhile a 30.1 inch ridge descends southeast over the
Midwest Tuesday through Wednesday night, moving into the Ohio River
Valley on Thursday with weak ridging of 29.9 inches extending back
northwest over Lake Superior. Another high pressure of 30.1 inches
will move south through Ontario on Friday building to 30.2 inches
over eastern Ontario by Saturday morning, extending a 30.1 inch
ridge over Lake Superior.



LSZ162-202000-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
1001 AM EDT Mon Jul 20 2026 /901 AM CDT Mon Jul 20 2026/

.REST OF TODAY...Southwest winds to 30 knots with a few gale
force gusts to 35 knots possible diminishing to 20 to 30 knots in
the afternoon, then veering west late. Patchy smoke by mid
afternoon. A slight chance of showers and thunderstorms by mid
afternoon. Some thunderstorms may be severe. Waves 3 to 6 feet
occasionally to 8 feet.
.TONIGHT...West winds 20 to 30 knots diminishing to 15 to
25 knots after midnight. Patchy smoke through midnight. Waves
subsiding to 1 to 3 feet, then building to 2 to 4 feet.
.TUESDAY...Northwest winds 15 to 25 knots becoming north 20 to
30 knots in the afternoon. Waves subsiding to 1 to 3 feet, then
building to 2 to 4 feet.
.TUESDAY NIGHT...Northwest winds 10 to 20 knots. Waves calm to
2 feet.
.WEDNESDAY...West winds 5 to 15 knots becoming southwest 10 to
20 knots by mid afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...West winds 5 to 15 knots. Waves calm to
2 feet.
.THURSDAY...Southwest winds 10 to 20 knots diminishing to 5 to
15 knots. A chance of showers. Waves building to 1 to 3 feet,
then subsiding to calm to 2 feet.
.FRIDAY...Southwest winds 5 to 15 knots. Waves calm to 2 feet.

$$

LSZ263-202000-
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-
1001 AM EDT Mon Jul 20 2026

.REST OF TODAY...Southwest winds 20 to 30 knots. Patchy smoke by
late morning. A slight chance of showers and thunderstorms by mid
afternoon. Some thunderstorms may be severe. Waves 4 to 7 feet
occasionally to 9 feet subsiding to 3 to 6 feet occasionally to
8 feet.
.TONIGHT...West winds 20 to 30 knots diminishing to 15 to
25 knots after midnight. Patchy smoke through midnight. A slight
chance of thunderstorms through midnight. A slight chance of
showers. Some thunderstorms may be severe. Waves subsiding to
2 to 4 feet, then building to 3 to 5 feet occasionally to 7 feet.
.TUESDAY...Northwest winds 20 to 30 knots veering north in the
afternoon. Waves building to 3 to 6 feet occasionally to 8 feet,
then subsiding to 2 to 4 feet.
.TUESDAY NIGHT...Northwest winds 10 to 20 knots. Waves subsiding
to calm to 2 feet.
.WEDNESDAY...West winds 5 to 15 knots becoming southwest 10 to
20 knots by mid afternoon. Waves building to 1 to 3 feet.
.WEDNESDAY NIGHT...Southwest winds 10 to 20 knots veering west
after midnight. Waves subsiding to calm to 2 feet, then building
to 1 to 3 feet.
.THURSDAY...Southwest winds 10 to 20 knots diminishing to 5 to
15 knots. A chance of showers. Waves subsiding to calm to 2 feet.
.FRIDAY...South winds 5 to 15 knots veering southwest. Waves calm
to 2 feet.

$$

LSZ264-202000-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
1001 AM EDT Mon Jul 20 2026

.REST OF TODAY...Southwest winds 20 to 30 knots. Patchy smoke by
late morning. A chance of showers and thunderstorms. Waves 3 to
6 feet occasionally to 8 feet.
.TONIGHT...West winds 15 to 25 knots. Patchy smoke through
midnight. A slight chance of thunderstorms through midnight. A
slight chance of showers. Waves subsiding to 2 to 4 feet, then
building to 3 to 5 feet occasionally to 7 feet.
.TUESDAY...Northwest winds 20 to 30 knots becoming north to
30 knots with a few gale force gusts to 35 knots possible in the
afternoon, then backing northwest late. A slight chance of
showers through early afternoon. Waves building to 4 to 7 feet
occasionally to 9 feet, then subsiding to 3 to 6 feet
occasionally to 8 feet.
.TUESDAY NIGHT...Northwest winds 15 to 25 knots diminishing to
10 to 20 knots after midnight. Waves subsiding to 1 to 3 feet.
.WEDNESDAY...West 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 becoming west
10 to 20 knots after midnight. Waves building to 1 to 3 feet,
then subsiding to calm to 2 feet.
.THURSDAY...Southwest winds 10 to 20 knots becoming west 5 to
15 knots. Waves subsiding to calm to 2 feet.
.FRIDAY...South winds 5 to 15 knots. Waves calm to 2 feet.

$$

LSZ265-202000-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
1001 AM EDT Mon Jul 20 2026

...GALE WATCH IN EFFECT FROM TUESDAY MORNING THROUGH LATE TUESDAY
NIGHT...

.REST OF TODAY...South winds 20 to 30 knots becoming southwest
15 to 25 knots in the afternoon. Patchy smoke. A slight chance of
showers and thunderstorms. Some thunderstorms may be severe by
mid afternoon. Waves 2 to 4 feet subsiding to 1 to 3 feet.
.TONIGHT...West winds 20 to 30 knots increasing to gales to
35 knots late. Patchy smoke. A chance of thunderstorms through
midnight. A slight chance of showers. Some thunderstorms may be
severe. Waves building to 2 to 4 feet, then subsiding to 1 to
3 feet.
.TUESDAY...Northwest gales to 45 knots. A slight chance of
showers. Waves building to 8 to 11 feet occasionally to 14 feet.
.TUESDAY NIGHT...Northwest gales to 40 knots diminishing to 20 to
30 knots after midnight. Waves subsiding to 3 to 6 feet
occasionally to 8 feet.
.WEDNESDAY...Northwest winds 20 to 30 knots becoming west 10 to
20 knots by mid afternoon. Waves subsiding to calm to 2 feet.
.WEDNESDAY NIGHT...West winds 10 to 20 knots increasing to 15 to
25 knots after midnight. Waves calm to 2 feet.
.THURSDAY...West winds 10 to 20 knots backing southwest. Waves
building to 1 to 3 feet, then subsiding to calm to 2 feet.
.FRIDAY...East winds 10 to 20 knots veering southwest. Waves calm
to 2 feet.

$$

LSZ266-202000-
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-
1001 AM EDT Mon Jul 20 2026

...GALE WATCH IN EFFECT FROM TUESDAY MORNING THROUGH LATE TUESDAY
NIGHT...

.REST OF TODAY...South winds 20 to 30 knots diminishing to 15 to
25 knots in the afternoon. Patchy smoke. A slight chance of
thunderstorms by late morning. A chance of showers. A chance of
thunderstorms by mid afternoon. Some thunderstorms may be severe
by mid afternoon. Waves 2 to 4 feet building to 3 to 5 feet
occasionally to 7 feet.
.TONIGHT...Southwest winds 15 to 25 knots veering west after
midnight, then increasing to 20 to 30 knots late. A chance of
thunderstorms through midnight. A chance of showers. Patchy smoke
after midnight. Waves subsiding to 2 to 4 feet, then building to
3 to 5 feet occasionally to 7 feet.
.TUESDAY...Northwest gales to 40 knots. A slight chance of
showers. Waves building to 9 to 12 feet occasionally to 15 feet.
.TUESDAY NIGHT...Northwest gales to 40 knots. Waves subsiding to
4 to 7 feet occasionally to 9 feet.
.WEDNESDAY...Northwest winds 20 to 30 knots becoming west 10 to
20 knots by mid afternoon. Waves subsiding to 2 to 4 feet.
.WEDNESDAY NIGHT...West winds 10 to 20 knots. Waves subsiding to
calm to 2 feet, then building to 1 to 3 feet.
.THURSDAY...West winds 10 to 20 knots becoming southwest 5 to
15 knots. Waves subsiding to calm to 2 feet.
.FRIDAY...South winds 5 to 15 knots. Waves calm to 2 feet.

$$

LSZ267-202000-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
1001 AM EDT Mon Jul 20 2026

...GALE WATCH IN EFFECT FROM TUESDAY MORNING THROUGH LATE TUESDAY
NIGHT...

.REST OF TODAY...South winds 15 to 25 knots increasing to 20 to
30 knots in the afternoon. Patchy smoke. A chance of showers by
late morning. Showers likely and a chance of thunderstorms by mid
afternoon. Some thunderstorms may be severe. Waves 2 to 4 feet
building to 3 to 5 feet occasionally to 7 feet.
.TONIGHT...South winds 15 to 25 knots veering west late. Showers
and a chance of thunderstorms through midnight, then a chance of
showers after midnight. Patchy smoke after midnight. Waves
subsiding to 2 to 4 feet, then building to 3 to 5 feet
occasionally to 7 feet.
.TUESDAY...West winds 20 to 30 knots becoming northwest gales to
40 knots in the afternoon. A slight chance of showers through
early afternoon. Waves building to 8 to 11 feet occasionally to
14 feet.
.TUESDAY NIGHT...Northwest gales to 35 knots. Waves subsiding to
5 to 8 feet occasionally to 10 feet.
.WEDNESDAY...Northwest winds 20 to 30 knots becoming west 15 to
25 knots by mid afternoon. Waves subsiding to 3 to 6 feet
occasionally to 8 feet.
.WEDNESDAY NIGHT...West winds 10 to 20 knots becoming southwest
5 to 15 knots after midnight. Waves subsiding to calm to 2 feet.
.THURSDAY...West winds 5 to 15 knots backing southwest. Waves
building to 1 to 3 feet, then subsiding to calm to 2 feet.
.FRIDAY...West winds 5 to 15 knots backing south. Waves calm to
2 feet.

$$

LSZ261-202000-
MAFOR 2015/
Superior West 12540 14630 12730. Waves 3 to 6 feet this
afternoon. Waves 3 to 5 feet subsiding to 2 to 4 feet tonight.
Waves 2 to 4 feet Tuesday morning.

Superior North Central 13530 12620 11630 12740. Waves 3 to 6
feet.

Superior South Central 12430 12530 11630 11640 11650 11750. A
chance of showers late this morning, then a chance of showers and
thunderstorms this afternoon. A chance of showers and
thunderstorms this evening. Waves 2 to 4 feet this afternoon.
Waves 2 to 4 feet building to 3 to 5 feet tonight. Waves 3 to 6
feet building to 4 to 7 feet Tuesday morning.

Superior East 12430 12436 11520 11620 11630 11740. A chance of
thunderstorms tonight. Waves 3 to 5 feet this afternoon and
tonight. Waves 3 to 5 feet building to 5 to 7 feet Tuesday
morning.

$$

WFO MQT

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