The National Weather Service has issued the beach hazards advisory for Ottawa, Muskegon, Mason, Oceana, Allegan and Van Buren counties through 11 p.m. Saturday. Beaches with particularly dangerous conditions include Grand Haven State Park and Marquette Park in Muskegon.
Swimmers should be aware of:
* High wave action: Strong currents and dangerous swimming conditions expected Saturday. High wave action makes swimming difficult and can tire even a strong swimmer quickly.
* Strong structural currents expected. 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.
* Strong longshore currents expected. 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 possible. 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.
The forecast for the Grand Haven area:
Saturday: Showers likely, then showers and thunderstorms after 10 am. High near 79. Calm wind becoming southwest around 6 mph. Chance of precipitation is 80 percent. New rainfall amounts between a quarter and half of an inch possible.
Saturday night: Showers and thunderstorms, mainly before 9 pm. Low around 66. Calm wind. Chance of precipitation is 80 percent. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Sunday: Partly sunny, with a high near 79. Calm wind.