* WHAT. High wave action, strong currents, and dangerous swimming conditions expected. Piers may be heavily swamped by waves. * WHERE. Mason, Oceana, Muskegon and Ottawa counties. * WHEN. Through 2 AM Monday. * IMPACTS. Strong currents can pull swimmers into deeper water and high waves can sweep people off piers.

* WHAT. South winds 15 to 25 knots with gusts up to 30 knots and waves 4 to 6 feet. * WHERE. Grand Haven to Manistee. * WHEN. Through 2 AM EDT Monday. * IMPACTS. Conditions will be hazardous to small craft.

* WHAT. Dangerously hot conditions with heat index values around 100 degrees. * WHERE. Portions of northern Indiana, southwest Michigan and northwest Ohio. * WHEN. From Monday morning through Friday evening. * IMPACTS. Extreme heat and humidity will significantly increase the potential for heat related illnesses, particularly for those working or participating in outdoor activities. * ADDITIONAL DETAILS. Heat indices into the mid to upper 90s are possible next weekend beyond the time of the watch. The prolonged nature of the event may magnify impacts as we move into the latter portions of the week.

* WHAT. Dangerously hot conditions with heat index values up to 100 possible. * WHERE. Portions of central, south central, southwest, and west central Michigan. * WHEN. From Monday afternoon through Friday evening. * IMPACTS. Heat related illnesses increase significantly during extreme heat and high humidity events. * ADDITIONAL DETAILS. Heat index values near 100 degrees will have a cumulative affect through the course of the week. Temperatures at night will only fall into the 70s. So, the affect of the heat will build through the course of the week.