Marine Forecast
Illustrated map of Grand Traverse Bay

Marine forecast

Lake Superior W of Manitou I.–Marquette (5+ nm)

current wind
6 kt N
Gusts
10 kt
Seas
3.3 ft
Air
50°F
72-hr peak
35 kt

Observed Tue 1:50 PM | LSZ265

Gusts now
10 kt
Seas now
3.3 ft
Air
50°F
72-hr peak
35 kt
Peak seas
11 ft

In brief

At 1:50 pm CDT on Oct 13, 2026, NDBC station BIGM4 (Big Bay, MI, 18 miles away) measured wind from the N at 6 kt, gusting to 10 kt; buoy 45025 measured seas of 3.3 ft. The NWS forecast for Lake Superior W of Manitou I.–Marquette (5+ nm), MI issued at 9:01 am CDT on Oct 13, 2026 reads, for rest of today: “Northeast winds 15 to 25 knots becoming north 10 to 20 knots in the afternoon, then backing northwest late. Waves 3 to 6 feet occasionally to 8 feet subsiding to 2 to 4 feet.”

Source: National Weather Service Marquette MI forecast; NDBC observations

Wind forecast · ktPeak 35 kt

05101520253035404550Wed 14Thu 15Fri 1605101520253035404550Wed 14Thu 15Fri 16
Sustained GustOct 13-16 | CDT

Seas forecast · ftPeak 11 ft

01234567891011Wed 14Thu 15Fri 1601234567891011Wed 14Thu 15Fri 16
Oct 13-16 | CDT

NWS marine forecast

PeriodForecast
Rest Of TodayNortheast winds 15 to 25 knots becoming north 10 to 20 knots in the afternoon, then backing northwest late. Waves 3 to 6 feet occasionally to 8 feet subsiding to 2 to 4 feet.
TonightNorthwest winds 10 to 20 knots increasing to 20 to 30 knots. Waves subsiding to 1 to 3 feet, then building to 2 to 4 feet.
WednesdayNorthwest winds 20 to 30 knots diminishing to 10 to 20 knots. Waves subsiding to 1 to 3 feet.
Wednesday NightNorth winds 5 to 15 knots veering southeast after midnight. Waves subsiding to calm to 2 feet.
ThursdaySouth winds 10 to 20 knots. A slight chance of showers by mid afternoon. Waves calm to 2 feet.
Thursday NightWest gales to 35 knots becoming northwest storm force winds to 55 knots after midnight. Showers. Waves building to 10 to 14 feet occasionally to 18 feet.
FridayNorthwest storm force winds to 60 knots diminishing to gales to 45 knots. A chance of rain showers. Waves building to 15 to 20 feet occasionally to 25 feet, then subsiding to 2 to 4 feet.
SaturdayWest winds 10 to 20 knots becoming southwest gales to 35 knots. Waves subsiding to calm to 2 feet, then building to 3 to 5 feet occasionally to 7 feet.

Issued Tue 9:01 AM by Marquette MI (product GLFLS).

Synopsis

Lake Superior remains situated between a 29.6 inch low over Wisconsin and a 30.2 inch high over Quebec. Ridging dominates over Lake Superior midweek as the low marches east and high pressure of 30.2 inches builds over the Dakotas by Wednesday afternoon. The high further builds to 30.3 inches over Lake Superior Wednesday night while a 29.9 inch low develops over Saskatchewan. By Thursday evening, this low weakens to 29.9 inches over northern Ontario as the high moves to New England, then the low rapidly deepens into Friday while tracking towards New England. Meanwhile, 30.6 inch high pressure expands across the Plains for Friday. Pressure increases rapidly over the Upper Great Lakes Friday afternoon into Saturday, reaching 30.4 inches by Saturday morning, then decreasing to 30.0 inches by Saturday night as the high collapses southeast. LSZ162-132000- Lake Superior west of a line from Saxon Harbor WI to Grand Portage MN beyond 5NM- 1001 AM EDT Tue Oct 13 2026 /901 AM CDT Tue Oct 13 2026/

TimeWindGustSeasWater
Tue 1:50 PM 6 kt N 10 kt — —
Tue 12:50 PM 10 kt N 12 kt — —
Tue 11:50 AM 10 kt N 12 kt — —
Tue 10:50 AM 10 kt NNE 12 kt — —
Tue 9:50 AM 8 kt NE 13 kt — —
Tue 8:50 AM 7 kt NE 16 kt — —
Tue 7:50 AM 7 kt NNE 8 kt — —
Tue 6:50 AM 3 kt ENE 5 kt — —
Tue 5:50 AM 0 kt 3 kt — —
Tue 4:50 AM 0 kt 3 kt — —
Tue 3:50 AM 1 kt SE 6 kt — —
Tue 2:50 AM 5 kt SE 8 kt — —

Observed Tue 1:50 PM at NDBC buoy BIGM4 (Big Bay, MI), 18.1 miles away. Seas from buoy 45025 (South Entry Buoy, South Keweenaw Peninsula, MI), 28.1 miles away, at Tue 12:00 PM.

What is the marine forecast for Lake Superior W of Manitou I.–Marquette (5+ nm) today?

Rest Of Today: Northeast winds 15 to 25 knots becoming north 10 to 20 knots in the afternoon, then backing northwest late. Waves 3 to 6 feet occasionally to 8 feet subsiding to 2 to 4 feet.

Is there a small craft advisory for Lake Superior W of Manitou I.–Marquette (5+ nm)?

No advisories, warnings or watches are in effect for NWS zone LSZ265 as of the last update on this page. Advisories can be issued at any time; check the current bulletin before leaving the dock.

How high are the waves at Lake Superior W of Manitou I.–Marquette (5+ nm) right now?

Seas are running 3.3 ft, measured at NDBC buoy BIGM4 Tue 1:50 PM, 18.1 miles from this zone. The forecast peaks at 11.0 ft Fri 9 AM.

What do the wind speeds in knots mean?

One knot is 1.15 mph. The National Weather Service issues a small craft advisory for sustained winds of roughly 22–33 knots or hazardous seas, a gale warning at 34–47 knots, and a storm warning at 48 knots and above. Exact advisory thresholds vary by forecast office and by water body — a bay reaches dangerous chop at a lower wind speed than open ocean.

Where does this forecast come from?

The forecast text is the National Weather Service's own marine bulletin for zone LSZ265, issued by Marquette MI, reproduced in full. The wind and seas charts are drawn from the NWS gridded forecast for a point inside the zone. Observations come from the nearest reporting NDBC buoy. We are not affiliated with NOAA or the National Weather Service.

Forecast: NOAA/NWS product GLFLS, issued Tue 9:01 AM. Observations: NOAA National Data Buoy Center station BIGM4, read Tue 1:50 PM. Retrieved Oct 13, 2:42 PM. Conditions offshore change faster than any page can be rebuilt, so check the current NWS bulletin and your own instruments before going out.