Munising to Grand Marais MI — Live Marine Advisories & Forecast
Lake Superior marine forecast zone · NWS UGC LSZ250 · Issued by NWS Marquette
1 active marine advisory · Last refreshed Wed, May 13, 9:39 PM EDT
South-shore Lake Superior nearshore zone covering the full Pictured Rocks National Lakeshore coastline from Munising east to Grand Marais harbor. Steep sandstone cliffs and minimal natural shelter make this zone particularly exposed to north-quadrant winds.
Lake
Lake Superior
NWS Office
NWS Marquette
Forecast Zone
LSZ250
Approx. length
42 mi
Active Advisories
Small Craft Advisory
Munising to Grand Marais MI; Grand Marais to Whitefish Point MI
Issued: Wed, May 13, 3:30 PM EDTEnds: Thu, May 14, 2:00 AM EDTBy: NWS Marquette MI
SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL 2 AM EDT THURSDAY
* WHAT...Northwest winds 15 to 25 kt with gusts up to 30 kt and
waves 4 to 7 ft occurring.
* WHERE...Munising to Grand Marais MI and Grand Marais to
Whitefish Point MI.
* WHEN...Until 2 AM EDT Thursday.
* IMPACTS...Conditions will be hazardous to small craft.
NWS Marquette regularly issues the following marine advisories for Munising to Grand Marais MI. Plain-English definitions from the NWS National Marine Glossary:
Small Craft AdvisoryIssued when sustained winds reach 22 knots (about 25 mph) or wave heights reach about 4 feet, conditions hazardous to small boats. Mariners in vessels under 30 ft should consider remaining in port.
Gale WarningIssued for sustained winds of 34 to 47 knots (about 39 to 54 mph). Conditions are dangerous to all vessels except large ships and require immediate precautions.
Storm WarningIssued for sustained winds of 48 to 63 knots (about 55 to 73 mph), excluding tropical cyclones. Hazardous to all vessels — small craft should not operate.
Special Marine WarningShort-fuse warning for severe thunderstorms, waterspouts, or sudden wind shifts of 34+ knots. Typically lasts up to 2 hours.
Frequently Asked Questions
What does a Small Craft Advisory mean for Munising to Grand Marais MI?
Issued when sustained winds reach 22 knots (about 25 mph) or wave heights reach about 4 feet, conditions hazardous to small boats. Mariners in vessels under 30 ft should consider remaining in port. On Munising to Grand Marais MI, this typically affects recreational boats out of Munising and Grand Marais.
Who issues marine forecasts for Munising to Grand Marais MI?
NWS Marquette (NWS office code MQT) issues all marine forecasts, advisories, warnings, and Special Marine Warnings for the Munising to Grand Marais MI forecast zone (UGC LSZ250).
Which Michigan counties border the Munising to Grand Marais MI marine zone?
Alger County. The shoreline runs roughly 42 miles between Munising and Grand Marais.
What advisory types are most common for this Lake Superior zone?
Small Craft Advisory, Gale Warning, Storm Warning, Special Marine Warning are the standard advisory products issued by NWS Marquette for Munising to Grand Marais MI. Small Craft Advisories are most frequent in spring and fall when winds and wave heights routinely exceed advisory thresholds.
How fresh is the data on this page?
Active advisories are pulled live from the NWS API at api.weather.gov when this page loads. The "Last refreshed" timestamp at the top of the page reflects the moment of fetch. NWS itself updates marine advisories continuously as conditions change.
Data Sources & Attribution
Active advisories on this page are pulled directly from the
NWS public API at
api.weather.gov, scoped to UGC zone LSZ250. The forecast and all official products
for Munising to Grand Marais MI are issued by
NWS Marquette.
Geographic context (cities, bordering counties, zone length) is curated from public maritime references.
Last fetched at Wed, May 13, 9:39 PM EDT.