Marine Products

The National Weather Service in Marquette provides marine forecast graphics for Lake Superior, including wave height, wind speed, and wind direction.  The National Weather Service in Chicago provides marine forecast graphics for Lake Michigan. The forecasts provide a graphical representation of forecast conditions on Lake Superior and Michigan for 48 hours. Feedback is always appreciated.

Click image for graphical forecast of selected area

Example graphic for western Lake Superior   Example graphic for eastern Lake Superior
Graphical Forecasts for Lake Superior East Half and West Half....(more detailed)

Example Graphic for Lake Superior   Example graphic for Lake Michigan
Graphical Forecasts all of Lake Superior     Graphical Forecasts for Lake Michigan

NWS Marine Text Products for the Western Great Lakes:

Near Shore Forecast -- Marquette Near Shore Forecast -- Duluth Near Shore Forecast -- Green Bay
Near Shore Forecast -- Gaylord Lake Superior Open Waters Lake Michigan Open Waters
Experimental Coded Port Forecast -- Marquette
Experimental Coded Port Forecast -- Duluth Experimental Coded Port Forecast -- Green Bay
Experimental Coded Port Forecast -- Gaylord

 Click here to complete a survey regarding the experimental port forecasts.


Click here for the National Marine Forecast Page.

Click here for active Special Marine Warnings and Advisories


Click on a station for current and past conditions

Marine observations provided and maintained by the National Data Buoy Center

Great Lakes Automated Observing Station map Slate Island Passage Island Rock of Ages Lakeshore Grand Marais, MN Lakeshore Silver Bay, MN Lakeshore Duluth, MN Lakeshore Port Wing, WI Devils Island Saxon Harbor, WI Western Lake Superior Buoy Lakeshore Ontonagon, MI Upper Entrance Portage Canal, MI Mid Lake Superior Buoy Lakeshore Big Bay, MI Marquette Coast Guard Stannard Rock Eastern Lake Superior Buoy Lakeshore Grand Marais, MI Point Iroquois, MI S.W. Pier, MI Little Rapids, MI Rock Cut, MI De Tour Village, MI Lakeshore Fairport, MI Northport Pier at Death's Door, WI Sister Bay, WI Lakeshore Menominee, MI Green Bay Entrance Light, WI Lakeshore Naubinway, MI Port Inland, MI Northern Lake Michigan Buoy Algoma City Marina, WI Lakeshore Kewaunee, WI Lakeshore Sheboygan, WI Lakeshore Port Washington, WI Lakeshore Milwaukee, WI Southern Lake Michigan Buoy Lakeshore Kenosha, WI Waukegan Harbor, IL Lakeshore Chicago, IL Calumet, IL Lakeshore Burns Harbor, IN Lakeshore Michigan City, IN Lakeshore South Haven, MI Lakeshore Muskegon, MI Lakeshore Ludington, MI Big Sable Point, MI Grand Traverse Light, MI Alplena Harbor Light, MI Gravelly Shoals Light, MI Toledo Light No.2, OH Lakeshore Toledo, OH

 

Lake Superior Temperatures
GLERL Lake Temperatures 
Lake Michigan Temperatures
GL Water Level 


The Nearshore Marine Forecast

NWS Marquette is responsible for issuing a nearshore marine forecast for waters within 5 miles of the south shore of Lake Superior from the Wisconsin/Michigan Border (Saxon Harbor) to Whitefish Point, Michigan, and the north shore of Lake Michigan from Cedar River, Michigan, to Seul Choix Point, Michigan. The nearshore forecast is issued during the same time frame that daylight savings time is in effect.

Nearshore forecasts will normally be basedupon guidance contained in the Lake Superior forecast (issued by NWS Marquette) and Lake Michigan forecast (issued by NWS Chicago). However, this guidance is not considered binding on the local nearshore marine forecast. The nearshore forecast is issued within one hour of the open lake forecast.

Content of the Nearshore Forecast

1. Gale or storm warnings or small craft advisories applicable to the nearshore area. (See below for the definition of a gale or storm warning.)

2. Expected wind direction and speed (rounded off to the nearest 5 knots).

3. Expected cloud cover, precipitation, thunderstorm or squall line activity and obstructions to visibility (3 miles or less).

4. Expected waves.

If a gale or storm warning is in effect for the open lake and not for nearshore waters, this will be mentioned in the text of the nearshore forecast following the winds. (e.g. "GALE WARNING IN EFFECT FOR THE OPEN LAKE").

Warnings and Advisories

Gale Warnings are issued for forecast winds of 34 to 47 knots, inclusive.

Storm Warnings are issued for forecast winds of 48 knots or more.

Small Craft Advisories are issued when sustained winds are forecast to be 18 to 33 knots and/or average waves of 4 feet or higher.

When waves are expected to reach or exceed three feet, people on or near piers, breakwaters, and beaches are advised to avoid these areas or exercise extreme caution until waves subside.

Special marine warnings

Special marine warnings are issued for short terms (usually 2 hours or less) when strong winds (34 knots ormore) are expected to occur. These winds are usually associated with squall lines or strong thunderstorms. A special marine warning maybe issued even though a small craft advisory is in effect. NWS Marquette's area of responsibility for special marine warnings include both the nearshore and open lake zones. (See the Severe Weather Page for active warnings.)



 

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