The advisory area includes shoreline beaches in Ottawa, Allegan and Van Buren counties.
The advisory calls for:
* High wave action: strong currents and dangerous swimming conditions expected.
* Strong structural currents expected.
* Strong longshore currents expected.
* Rip currents possible.
* North to northwest winds of 15-25 mph, with waves of 4-7 feet, will create hazardous swimming conditions.
* The north side of piers will be especially dangerous tonight as strong structural currents are expected to develop.
* Longshore currents are expected away from the piers.
High wave action makes swimming difficult and can tire even a strong swimmer quickly.
Structural currents form along piers where longshore currents and wave action flow into the structure. Structural currents can sweep you out into deeper water along the pier structure.
A longshore current is a lake current that moves parallel to shore. Longshore currents can be strong enough to prevent swimmers from being able to keep their feet on the bottom, making it difficult to return to shore.
Rip currents are powerful channels of water flowing quickly away from shore, which occur most often at low spots or breaks in sandbars. Rip currents can sweep you into deeper water.