048
FZUS63 KMQT 122001
GLFLS

Open Lake Forecast for Lake Superior
National Weather Service Marquette MI
401 PM EDT Sat Jul 12 2025

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 29.8 inch trough moves across the lake through this afternoon as a
low over northern Ontario deepens to 29.6 inches. This low deepens
further to 29.4 inches tonight as it drifts northeast towards Hudson
Bay while 30.0 inch high pressure builds just south of the Great
Lakes basin. The high maintains strength and position on Sunday
while the low deepens to 29.2 inches over Hudson Bay. On Monday,
weak ridging near 30.0 inches builds over Lake Superior as 29.7 inch
low pressure forms over the High Plains. This low will pass a 29.9
inch trough over Lake Superior Tuesday before 30.1 inch high
pressure builds in its wake over northern Ontario Wednesday into
Thursday.


LSZ162-130800-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-
401 PM EDT Sat Jul 12 2025 /301 PM CDT Sat Jul 12 2025/

.LATE THIS AFTERNOON...West winds 15 to 25 knots. Areas of smoke.
A slight chance of showers and thunderstorms. Waves calm to
2 feet.
.TONIGHT...West winds 10 to 20 knots backing southwest after
midnight. Areas of smoke. Waves calm to 2 feet.
.SUNDAY...Southwest winds 10 to 20 knots increasing to 15 to
25 knots in the afternoon. Areas of smoke. Waves building to 1 to
3 feet.
.SUNDAY NIGHT...Southwest winds 15 to 25 knots becoming west
10 to 20 knots after midnight. A slight chance of showers and
thunderstorms through midnight. Areas of smoke. Waves subsiding
to calm to 2 feet.
.MONDAY...West winds 10 to 20 knots backing southwest by mid
afternoon. Areas of smoke through early afternoon. Waves calm to
2 feet.
.MONDAY NIGHT...East winds 5 to 15 knots. A chance of showers.
Waves calm to 2 feet.
.TUESDAY...Northeast winds 10 to 20 knots. A chance of showers
through early afternoon, then showers likely by mid afternoon.
Waves calm to 2 feet.
.TUESDAY NIGHT...Northeast winds 10 to 20 knots. Showers likely
through midnight. A chance of thunderstorms. A chance of showers
after midnight. Waves calm to 2 feet.
.WEDNESDAY...Northeast winds 10 to 20 knots. A chance of showers.
Waves calm to 2 feet.
.THURSDAY...Northeast winds 10 to 20 knots becoming northwest
5 to 15 knots. Waves calm to 2 feet.

$$

LSZ263-130800-
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 Sat Jul 12 2025

.LATE THIS AFTERNOON...West winds 10 to 20 knots. Areas of smoke.
A chance of showers and thunderstorms. Waves calm to 2 feet.
.TONIGHT...West winds 10 to 20 knots. Areas of smoke. Waves
building to 1 to 3 feet.
.SUNDAY...Southwest winds 10 to 20 knots increasing to 15 to
25 knots in the afternoon. Areas of smoke. Waves building to 2 to
4 feet.
.SUNDAY NIGHT...Southwest winds 10 to 20 knots becoming west 5 to
15 knots late. Areas of smoke through midnight. A slight chance
of showers and thunderstorms through midnight. Waves subsiding to
1 to 3 feet.
.MONDAY...West winds 5 to 15 knots backing southwest by mid
afternoon. Waves subsiding to calm to 2 feet.
.MONDAY NIGHT...Southeast winds 5 to 15 knots. A chance of
showers. Waves calm to 2 feet.
.TUESDAY...South winds 5 to 15 knots. A chance of showers. Waves
calm to 2 feet.
.TUESDAY NIGHT...North winds 5 to 15 knots veering northeast
after midnight. Showers likely through midnight. A chance of
thunderstorms. A chance of showers after midnight. Waves calm to
2 feet.
.WEDNESDAY...Northeast winds 5 to 15 knots. A chance of showers.
Waves calm to 2 feet.
.THURSDAY...Northeast winds 5 to 15 knots backing west. Waves
calm to 2 feet.

$$

LSZ264-130800-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
401 PM EDT Sat Jul 12 2025

.LATE THIS AFTERNOON...West winds 5 to 15 knots. A chance of
showers and thunderstorms. Waves calm to 2 feet.
.TONIGHT...West winds 10 to 20 knots. A slight chance of showers
through midnight. Areas of smoke. Waves building to 2 to 4 feet.
.SUNDAY...Southwest winds 10 to 20 knots. Areas of smoke. Waves
2 to 4 feet.
.SUNDAY NIGHT...Southwest winds 10 to 20 knots becoming west 5 to
15 knots late. A slight chance of showers and thunderstorms
through midnight. Areas of smoke. Waves subsiding to 1 to 3 feet.
.MONDAY...West winds 5 to 15 knots backing southwest by mid
afternoon. Waves subsiding to calm to 2 feet.
.MONDAY NIGHT...South winds 5 to 15 knots backing southeast after
midnight. A chance of showers after midnight. Waves calm to
2 feet.
.TUESDAY...South winds 5 to 15 knots. A chance of showers. Waves
calm to 2 feet.
.TUESDAY NIGHT...North winds 5 to 15 knots. A chance of showers.
Waves calm to 2 feet.
.WEDNESDAY...Northeast winds 5 to 15 knots backing north. A
chance of showers. Waves calm to 2 feet.
.THURSDAY...North winds 5 to 15 knots backing west. Waves calm to
2 feet.

$$

LSZ265-130800-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
401 PM EDT Sat Jul 12 2025

.LATE THIS AFTERNOON...West winds 5 to 15 knots. A chance of
showers and thunderstorms. Waves calm to 2 feet.
.TONIGHT...West winds 5 to 15 knots increasing to 10 to 20 knots
after midnight. Areas of smoke. Waves calm to 2 feet.
.SUNDAY...West winds 10 to 20 knots backing south late. Areas of
smoke. Waves calm to 2 feet.
.SUNDAY NIGHT...Southwest winds 10 to 20 knots increasing to
15 to 25 knots after midnight, then becoming west 10 to 20 knots
late. A slight chance of showers and thunderstorms through
midnight. Areas of smoke. Waves calm to 2 feet.
.MONDAY...West winds 10 to 20 knots diminishing to 5 to 15 knots
by mid afternoon. Waves calm to 2 feet.
.MONDAY NIGHT...Southeast winds 5 to 15 knots. Waves calm to
2 feet.
.TUESDAY...South winds 10 to 20 knots. A chance of showers and
thunderstorms. Waves calm to 2 feet.
.TUESDAY NIGHT...Northwest winds 10 to 20 knots veering north
after midnight. A chance of showers and thunderstorms. Waves calm
to 2 feet.
.WEDNESDAY...North winds 10 to 20 knots. A chance of showers.
Waves calm to 2 feet.
.THURSDAY...North winds 10 to 20 knots backing northwest. Waves
calm to 2 feet.

$$

LSZ266-130800-
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 Sat Jul 12 2025

.LATE THIS AFTERNOON...West winds 5 to 15 knots. A chance of
showers and a slight chance of thunderstorms. Waves calm to
2 feet.
.TONIGHT...Southwest winds 5 to 15 knots increasing to 10 to
20 knots after midnight, then veering west late. A slight chance
of showers and thunderstorms through midnight. Areas of smoke.
Waves building to 1 to 3 feet.
.SUNDAY...Southwest winds 10 to 20 knots backing south late.
Areas of smoke. Waves building to 2 to 4 feet, then subsiding to
1 to 3 feet.
.SUNDAY NIGHT...South winds 10 to 20 knots becoming southwest
15 to 25 knots after midnight, then diminishing to 10 to 20 knots
late. Areas of smoke. A slight chance of showers and
thunderstorms. Waves 1 to 3 feet.
.MONDAY...West winds 10 to 20 knots diminishing to 5 to 15 knots
by mid afternoon. Waves subsiding to calm to 2 feet.
.MONDAY NIGHT...Southeast winds 5 to 15 knots. Waves calm to
2 feet.
.TUESDAY...South winds 10 to 20 knots. A chance of showers. Waves
calm to 2 feet.
.TUESDAY NIGHT...Southwest winds 10 to 20 knots veering north
after midnight. A chance of showers and thunderstorms. Waves
building to 1 to 3 feet, then subsiding to calm to 2 feet.
.WEDNESDAY...North winds 10 to 20 knots. A chance of showers.
Waves calm to 2 feet.
.THURSDAY...North winds 10 to 20 knots becoming northwest 5 to
15 knots. Waves calm to 2 feet.

$$

LSZ267-130800-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
401 PM EDT Sat Jul 12 2025

.LATE THIS AFTERNOON...West winds 10 to 20 knots. A slight chance
of showers and thunderstorms. Waves calm to 2 feet.
.TONIGHT...West winds 10 to 20 knots becoming southwest 5 to
15 knots after midnight, then increasing to 10 to 20 knots late.
A slight chance of showers and thunderstorms through midnight.
Areas of smoke after midnight. Waves calm to 2 feet.
.SUNDAY...Southwest winds 10 to 20 knots backing south late.
Areas of smoke. Waves calm to 2 feet.
.SUNDAY NIGHT...South winds 10 to 20 knots becoming southwest
15 to 25 knots after midnight, then diminishing to 10 to 20 knots
late. Areas of smoke. A slight chance of showers. A slight chance
of thunderstorms after midnight. Waves building to 1 to 3 feet.
.MONDAY...West winds 10 to 20 knots diminishing to 5 to 15 knots
by mid afternoon. Areas of smoke through early afternoon. A
slight chance of showers and thunderstorms through early
afternoon. Waves subsiding to calm to 2 feet.
.MONDAY NIGHT...Southeast winds 5 to 15 knots. Waves calm to
2 feet.
.TUESDAY...South winds 10 to 20 knots. A chance of showers. Waves
calm to 2 feet.
.TUESDAY NIGHT...Southwest winds 10 to 20 knots. A chance of
showers and thunderstorms. Waves building to 1 to 3 feet.
.WEDNESDAY...North winds 10 to 20 knots. A chance of showers and
thunderstorms. Waves subsiding to calm to 2 feet.
.THURSDAY...North winds 10 to 20 knots. Waves calm to 2 feet.

$$

LSZ261-130200-
MAFOR 1221/
Superior West 13620 14520 11520. Waves 1 to 3 feet.

Superior North Central 14620 11620 11520 12530. A chance of
showers and thunderstorms early this evening. Waves 1 to 3 feet
tonight. Waves 2 to 4 feet Sunday.

Superior South Central 11610 11510 11520 13620 12510. A chance of
showers and thunderstorms this evening. Waves 2 feet or less.

Superior East 12610 11510 12520 13510. Waves 1 to 3 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