304
FZUS63 KMQT 202001
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
401 PM 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.



LSZ162-210800-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
401 PM EDT Mon Jul 20 2026 /301 PM CDT Mon Jul 20 2026/

.LATE THIS AFTERNOON...West winds 20 to 30 knots. Patchy smoke. A
slight chance of showers and thunderstorms. Some thunderstorms
may be severe. Waves 3 to 6 feet occasionally to 8 feet.
.TONIGHT...West winds 20 to 30 knots. Patchy smoke through
midnight. A slight chance of showers and thunderstorms after
midnight. Waves subsiding to 1 to 3 feet.
.TUESDAY...Northwest winds 15 to 25 knots increasing to 20 to
30 knots in the afternoon, then veering north late. Waves
building to 2 to 4 feet, then subsiding to calm to 2 feet.
.TUESDAY NIGHT...North winds 10 to 20 knots backing northwest
after midnight. Waves calm to 2 feet.
.WEDNESDAY...Northwest winds 5 to 15 knots becoming southwest
10 to 20 knots by mid afternoon. Waves calm to 2 feet.
.WEDNESDAY NIGHT...West winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. Waves calm to 2 feet.
.THURSDAY...Southwest winds 10 to 20 knots. Waves building to
1 to 3 feet, then subsiding to calm to 2 feet.
.THURSDAY NIGHT...Southwest winds 5 to 15 knots. Waves calm to
2 feet.
.FRIDAY...Southwest winds 10 to 20 knots. A chance of showers.
Waves calm to 2 feet.
.SATURDAY...Southwest winds 15 to 25 knots diminishing to 10 to
20 knots. A chance of showers. Waves calm to 2 feet.

$$

LSZ263-210800-
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-
401 PM EDT Mon Jul 20 2026

.LATE THIS AFTERNOON...West winds 20 to 30 knots. Patchy smoke. A
chance of showers and thunderstorms. 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. A chance
of showers. A slight chance of thunderstorms after midnight.
Waves subsiding to 3 to 5 feet occasionally to 7 feet.
.TUESDAY...Northwest winds 20 to 30 knots veering north late.
Waves subsiding to 2 to 4 feet.
.TUESDAY NIGHT...North winds 15 to 25 knots becoming northwest
10 to 20 knots after midnight. Patchy smoke through midnight.
Waves subsiding to calm to 2 feet.
.WEDNESDAY...Northwest winds 10 to 20 knots backing southwest 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 15 to 25 knots. Waves building to
2 to 4 feet, then subsiding to 1 to 3 feet.
.THURSDAY NIGHT...Southwest winds 10 to 20 knots. A chance of
showers and thunderstorms. Waves subsiding to calm to 2 feet.
.FRIDAY...Southwest winds 10 to 20 knots increasing to 15 to
25 knots. Waves calm to 2 feet.
.SATURDAY...Southwest winds 15 to 25 knots diminishing to 10 to
20 knots. A chance of showers. Waves building to 1 to 3 feet,
then subsiding to calm to 2 feet.

$$

LSZ264-210800-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
401 PM EDT Mon Jul 20 2026

.LATE THIS AFTERNOON...Southwest winds 15 to 25 knots. A chance
of showers and thunderstorms. Some thunderstorms may be severe.
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
chance of showers. Some thunderstorms may be severe. Waves
subsiding to 3 to 5 feet occasionally to 7 feet.
.TUESDAY...Northwest winds 20 to 30 knots increasing to 30 knots
with a few gale force gusts to 35 knots possible in the
afternoon. 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 20 to 30 knots diminishing to
15 to 25 knots after midnight. Waves subsiding to 1 to 3 feet.
.WEDNESDAY...Northwest winds 10 to 20 knots backing west by mid
afternoon. Waves subsiding to calm to 2 feet.
.WEDNESDAY NIGHT...West winds 10 to 20 knots. Waves building to
1 to 3 feet, then subsiding to calm to 2 feet.
.THURSDAY...Southwest winds 10 to 20 knots. Waves 1 to 3 feet.
.THURSDAY NIGHT...Southwest winds 5 to 15 knots increasing to
10 to 20 knots after midnight. A chance of showers and
thunderstorms. Waves subsiding to calm to 2 feet.
.FRIDAY...Southwest winds 10 to 20 knots increasing to 15 to
25 knots. Waves calm to 2 feet.
.SATURDAY...Southwest winds 15 to 25 knots diminishing to 10 to
20 knots. A chance of showers. Waves calm to 2 feet.

$$

LSZ265-210800-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
401 PM EDT Mon Jul 20 2026

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

.LATE THIS AFTERNOON...South winds 20 to 30 knots. A chance of
showers and thunderstorms. Some thunderstorms may be severe.
Waves 2 to 4 feet.
.TONIGHT...Southwest winds 20 to 30 knots veering west after
midnight, then increasing to gales to 35 knots late. A slight
chance of thunderstorms through midnight. A chance of showers.
Some thunderstorms may be severe. Waves building to 3 to 5 feet
occasionally to 7 feet.
.TUESDAY...Northwest gales to 40 knots. A slight chance of
showers through early afternoon. Waves building to 7 to 10 feet
occasionally to 13 feet.
.TUESDAY NIGHT...Northwest gales to 40 knots diminishing to 20 to
30 knots late. Patchy smoke after midnight. Waves subsiding to
3 to 6 feet occasionally to 8 feet.
.WEDNESDAY...Northwest winds 20 to 30 knots becoming west 15 to
25 knots by mid afternoon. Waves subsiding to calm to 2 feet.
.WEDNESDAY NIGHT...West winds 15 to 25 knots. Waves calm to
2 feet.
.THURSDAY...West winds 10 to 20 knots becoming southwest 5 to
15 knots by mid afternoon. Waves building to 1 to 3 feet, then
subsiding to calm to 2 feet.
.THURSDAY NIGHT...Southwest winds 10 to 20 knots increasing to
15 to 25 knots after midnight. Waves calm to 2 feet.
.FRIDAY...Southwest winds 10 to 20 knots. Waves calm to 2 feet.
.SATURDAY...Southwest winds 15 to 25 knots veering west. A chance
of showers. Waves calm to 2 feet.

$$

LSZ266-210800-
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-
401 PM EDT Mon Jul 20 2026

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

.LATE THIS AFTERNOON...South winds 15 to 25 knots. Patchy smoke.
A chance of showers and thunderstorms. Some thunderstorms may be
severe. Waves 3 to 6 feet occasionally to 8 feet.
.TONIGHT...South 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. Some
thunderstorms may be severe. Waves subsiding to 3 to 6 feet
occasionally to 8 feet.
.TUESDAY...Northwest gales to 40 knots. A slight chance of
showers through early afternoon. Waves building to 8 to 12 feet
occasionally to 15 feet.
.TUESDAY NIGHT...Northwest gales to 40 knots diminishing to 20 to
30 knots late. A slight chance of showers through midnight. Waves
subsiding to 4 to 7 feet occasionally to 9 feet.
.WEDNESDAY...Northwest winds 20 to 30 knots becoming west 15 to
25 knots by mid afternoon. Waves subsiding to 2 to 4 feet.
.WEDNESDAY NIGHT...West winds 15 to 25 knots. Waves subsiding to
calm to 2 feet, then building to 1 to 3 feet.
.THURSDAY...West winds 10 to 20 knots backing southwest by mid
afternoon. Waves 1 to 3 feet.
.THURSDAY NIGHT...South winds 5 to 15 knots becoming southwest
10 to 20 knots after midnight. Waves subsiding to calm to 2 feet.
.FRIDAY...South winds 5 to 15 knots increasing to 10 to 20 knots.
Waves calm to 2 feet.
.SATURDAY...South winds 10 to 20 knots veering southwest. A
chance of showers, then showers likely. Waves building to 1 to
3 feet.

$$

LSZ267-210800-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
401 PM EDT Mon Jul 20 2026

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

.LATE THIS AFTERNOON...South winds 20 to 30 knots. A chance of
showers and thunderstorms. Waves 3 to 5 feet occasionally to
7 feet.
.TONIGHT...South winds 15 to 25 knots veering west late. A chance
of thunderstorms through midnight. A 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...West winds 20 to 30 knots becoming northwest gales to
40 knots in the afternoon. A chance of showers. Waves building to
8 to 12 feet occasionally to 15 feet.
.TUESDAY NIGHT...Northwest gales to 35 knots. A slight chance of
showers through midnight. Waves subsiding to 5 to 8 feet
occasionally to 10 feet.
.WEDNESDAY...Northwest winds 20 to 30 knots backing west by mid
afternoon. Waves subsiding to 3 to 6 feet occasionally to 8 feet.
.WEDNESDAY NIGHT...West winds 10 to 20 knots diminishing to 5 to
15 knots after midnight. Waves subsiding to calm to 2 feet.
.THURSDAY...West winds 10 to 20 knots diminishing to 5 to
15 knots by mid afternoon. Waves building to 1 to 3 feet, then
subsiding to calm to 2 feet.
.THURSDAY NIGHT...South winds 5 to 15 knots becoming southwest
10 to 20 knots after midnight. Waves calm to 2 feet.
.FRIDAY...Southwest winds 5 to 15 knots becoming south 10 to
20 knots. Waves calm to 2 feet.
.SATURDAY...South winds 10 to 20 knots veering southwest. Showers
likely. Waves building to 1 to 3 feet.

$$

LSZ261-210200-
MAFOR 2021/
Superior West 14630 14730. Waves 3 to 5 feet subsiding to 1 to 3
feet tonight. Waves 1 to 3 feet Tuesday.

Superior North Central 11530 11630 11620 11630 12740 12750. A
chance of showers and thunderstorms this evening, then a chance
of showers overnight. A chance of showers Tuesday morning. Waves
3 to 6 feet.

Superior South Central...GALE WARNING IN EFFECT...11430 11530
11630 12640 12750 11760. A chance of thunderstorms early this
evening, then a chance of showers and thunderstorms this evening.
A chance of showers overnight. A chance of showers Tuesday
morning. Waves 2 to 4 feet building to 3 to 5 feet tonight. Waves
5 to 8 feet building to 7 to 10 feet Tuesday.

Superior East...GALE WARNING IN EFFECT...12436 11520 11620 11630
11740 12750. A chance of thunderstorms this evening. Waves 3 to 6
feet tonight. Waves 5 to 8 feet building to 7 to 10 feet Tuesday.

$$

WFO MQT

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