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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The National Weather Service has a alert in force for Mackinac Island and the Straits

As of Mon, October 12 at 7:51 AM.

Yellow

Small Craft Advisory

* WHAT...Highest gusts up to 25 kts from the east and highest waves around 4 feet expected. * WHERE...Straits of Mackinac within 5 nm of Mackinac Bridge including Mackinac Island, St Ignace to False Detour Channel and 5NM East of Mackinac Bridge to Presque Isle Light MI including Bois Blanc Island. * WHEN...From 8 PM this evening to 8 AM EDT Tuesday. * IMPACTS...Conditions will be hazardous to small craft.

What to do

Inexperienced mariners, especially those operating smaller vessels, should avoid navigating in hazardous conditions.

Valid from: Mon, October 12 at 8:00 PM
Until: Tue, October 13 at 8:00 AM
Area: Straits of Mackinac within 5 nm of Mackinac Bridge including Mackinac Island; St Ignace to False Detour Channel; 5NM East of Mackinac Bridge to Presque Isle Light MI including Bois Blanc Island
Last updated: Mon, October 12 at 1:43 AM

Where to check, before and during

NWS Gaylord — forecast and warningsThe forecast office for the island and the Straits: warnings, radar and the forecast.

Straits of Mackinac marine forecast (LHZ345)The live marine forecast for the Straits of Mackinac zone the ferries cross.

Mackinac County Emergency ManagementCounty emergency management — local alerting and preparedness.

Arnold Transit — winter service and ice conditionsThe operator's own word on winter service and ice suspensions; text MackinacFerry to 41411 for service alerts.

Get an email when a warning is issued

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.

Worth knowing

The Straits have their own forecast zone

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 is its own season of alerts

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.

Lakeshore flooding is the island's flood

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.