Marine forecast
Lake Superior: Grand Marais–Whitefish Pt, MI
- current wind
- 13 kt NW
- Gusts
- 15 kt
- Seas
- 1.3 ft
- Period
- 5 sec
- 72-hr peak
- 35 kt
Observed Tue 1:50 PM | LSZ267
- Gusts now
- 15 kt
- Seas now
- 1.3 ft · 5 sec
- 72-hr peak
- 35 kt
- Peak seas
- 20 ft
In brief
At 1:50 pm CDT on Oct 13, 2026, NDBC station GRMM4 (Grand Marais, MI, 28 miles away) measured wind from the NW at 13 kt, gusting to 15 kt; buoy 4403587 measured seas of 1.3 ft. The NWS forecast for Lake Superior: Grand Marais–Whitefish Pt, MI issued at 9:01 am CDT on Oct 13, 2026 reads, for rest of today: “Northeast winds 10 to 20 knots diminishing to 5 to 15 knots in the afternoon, then becoming northwest 10 to 20 knots late. A slight chance of showers by late morning.”
Source: National Weather Service Marquette MI forecast; NDBC observations
Wind forecast · ktPeak 35 kt
Seas forecast · ftPeak 20 ft
NWS marine forecast
| Period | Forecast |
|---|---|
| Rest Of Today | Northeast winds 10 to 20 knots diminishing to 5 to 15 knots in the afternoon, then becoming northwest 10 to 20 knots late. A slight chance of showers by late morning. Waves 2 to 4 feet subsiding to calm to 2 feet. |
| Tonight | Northwest winds 15 to 25 knots. Waves building to 3 to 5 feet occasionally to 7 feet. |
| Wednesday | Northwest winds 15 to 25 knots. Waves 3 to 5 feet occasionally to 7 feet. |
| Wednesday Night | North winds 10 to 20 knots veering east after midnight. Waves subsiding to calm to 2 feet. |
| Thursday | Southeast winds 10 to 20 knots veering south by mid afternoon. A slight chance of showers by mid afternoon. Waves calm to 2 feet. |
| Thursday Night | South winds 10 to 20 knots becoming northwest gales to 40 knots after midnight. Showers. Waves building to 10 to 14 feet occasionally to 18 feet. |
| Friday | North storm force winds to 55 knots diminishing to gales to 45 knots. Rain showers likely. Waves building to 17 to 22 feet occasionally to 28 feet, then subsiding to 5 to 8 feet occasionally to 10 feet. |
| Saturday | West winds 10 to 20 knots becoming southwest 20 to 30 knots. Waves subsiding to 1 to 3 feet, then building to 4 to 7 feet occasionally to 9 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/
Recent buoy conditions
| Time | Wind | Gust | Seas | Water |
|---|---|---|---|---|
| Tue 1:50 PM | 13 kt NW | 15 kt | — | — |
| Tue 12:50 PM | 12 kt N | 15 kt | — | — |
| Tue 11:50 AM | 12 kt N | 14 kt | — | — |
| Tue 10:50 AM | 4 kt E | 5 kt | — | — |
| Tue 9:40 AM | 5 kt ESE | 6 kt | — | — |
| Tue 8:50 AM | 4 kt ESE | 6 kt | — | — |
| Tue 7:50 AM | 9 kt E | 11 kt | — | — |
| Tue 6:50 AM | 13 kt E | 14 kt | — | — |
| Tue 4:50 AM | 10 kt E | 13 kt | — | — |
| Mon 10:40 PM | 16 kt E | 17 kt | — | — |
| Mon 9:50 PM | 10 kt ESE | 13 kt | — | — |
| Mon 8:50 PM | 16 kt E | 20 kt | — | — |
Observed Tue 1:50 PM at NDBC buoy GRMM4 (Grand Marais, MI), 27.6 miles away. Seas from buoy 4403587 (Whitefish Bay), 35.5 miles away, at Tue 1:20 PM.
Frequently asked questions
What is the marine forecast for Lake Superior: Grand Marais–Whitefish Pt today?
Rest Of Today: Northeast winds 10 to 20 knots diminishing to 5 to 15 knots in the afternoon, then becoming northwest 10 to 20 knots late. A slight chance of showers by late morning. Waves 2 to 4 feet subsiding to calm to 2 feet.
Is there a small craft advisory for Lake Superior: Grand Marais–Whitefish Pt?
No advisories, warnings or watches are in effect for NWS zone LSZ267 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: Grand Marais–Whitefish Pt right now?
Seas are running 1.3 ft at a 5-second period, measured at NDBC buoy GRMM4 Tue 1:50 PM, 27.6 miles from this zone. The forecast peaks at 20.0 ft Fri 1 PM.
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 LSZ267, 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 GRMM4, 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.