* WHAT...High wave action, strong currents, and dangerous swimming conditions expected. Piers may be swamped by waves. * WHERE...Mason, Oceana, Muskegon, Ottawa and Allegan counties. * WHEN...From late tonight through Sunday evening. * IMPACTS...Strong currents can pull swimmers into deeper water and high waves can sweep people off piers. * ADDITIONAL DETAILS...Winds from the south will make waves and currents more hazardous near south piers, including at Grand Haven State Park and Pere Marquette Park in Muskegon. Remain out of the water to avoid hazardous swimming conditions and do not venture out on piers. Please check with your local authorities on potential beach closures.