The coastal hazard message was issued Thursday afternoon for beaches from St. Joseph to Manistee.
What to expect:
— High wave action, strong currents and dangerous swimming conditions.
— Strong structural currents.
— Strong longshore currents.
— Rip currents.
Beaches with particularly dangerous conditions include Grand Haven State Park, Pere Marquette Park in Muskegon, Holland State Park, North Beach and South Beach in South Haven, Mears State Park in Pentwater, and Stearns Park in Ludington.
The weather bureau said late Friday that winds and waves will be decreasing Saturday morning, but will still be hazardous for swimmers until about noon Saturday.
— 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.
Grand Haven forecast:
Saturday: Mostly sunny, with a high near 74. West-northwest wind around 10 mph.