Loading Weather & Straits Warnings…
National Weather Service alerts in force for the island and for the Straits of Mackinac ferry crossing — gales, winter storms, lakeshore flooding — plus the wind right now.
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Small Craft Advisory
Yellow · until Mon 7:00 PM
Everything here rides on the water and the weather: the boats, the freight, the flights, the ride around M-185. It is not an alert service; sign up for the official channels below.
As of Sun, August 23 at 9:50 PM.
* WHAT...Highest gusts up to 30 kts from the northwest and highest waves around 6 feet. * WHERE...In Lake Huron, Straits of Mackinac within 5 nm of Mackinac Bridge including Mackinac Island. In Lake Michigan, Grand Traverse Bay south of a line Grand Traverse Light to Norwood MI, Seul Choix Point to 5NM West of Mackinac Bridge, Norwood MI to 5NM West of Mackinac Bridge including Little Traverse Bay and Sleeping Bear Point to Grand Traverse Light MI. * WHEN...Until 7 PM EDT Monday. * IMPACTS...Conditions will be hazardous to small craft.
Inexperienced mariners, especially those operating smaller vessels, should avoid navigating in hazardous conditions.
A moderate breeze (about 27 km/h, gusts to 52), out of the west-northwest.
Strongest gusts forecast over the next 24 hours: about 57 km/h. Wind words follow the Beaufort scale. This is a weather model’s forecast for the hour, not a measurement — exposed ground above town will see more.
When a warning is in force
Official warnings, forwarded the moment the national service issues one for the area — headline and all, in its own words. Nothing in between. No account, one-click unsubscribe.
The waters within five nautical miles of the Mackinac Bridge — the ferry crossing — are NWS marine zone LHZ345, and its warnings show here alongside the island's. A Gale Warning or Storm Warning on the Straits is the weather that stops boats; a Small Craft Advisory is routine for small boats and does not by itself mean the ferries stop — that call always belongs to the operators and their captains.
Winter storms, blizzard conditions and freezing spray close the gap between the island and the mainland: the ferries thin out, pause for ice, and the air taxi becomes the link. In April 2026 the start of the ferry season itself was postponed because ice lingered in the Straits. The operators announce service changes — text MackinacFerry to 41411 for Arnold Transit's alerts.
There is no river here — when water threatens, it is the lake: storm winds piling water and waves onto the shoreline. Lakeshore Flood advisories and warnings for the island show on this page; the lake's slow seasonal level is a separate story, on the island's lake-level page.
Alert data: U.S. National Weather Service, source weather.gov — a public-domain product of the U.S. federal government. Alerts are shown as issued; this page reads the active alerts the NWS has posted for Mackinac Island and the Straits. Wind forecast: Open-Meteo (CC BY 4.0). This page is not an alert service — sign up to the official channels above.