* WHAT. Dangerously hot conditions with heat index values into the upper 90s. * WHERE. Portions of northern Indiana and southwest Michigan. * WHEN. Until 8 PM EDT /7 PM CDT/ this evening. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses to occur. * ADDITIONAL DETAILS. Heat stress increases with the number of consecutive hot days. The effects of heat are most impactful for more vulnerable urban populations.

* WHAT. Flooding caused by excessive rainfall is possible. * WHERE. Portions of central and west central Michigan, including the following counties, in central Michigan, Clare, Gratiot, Isabella, Mecosta, Montcalm and Osceola. In west central Michigan, Lake, Mason, Muskegon, Newaygo and Oceana. * WHEN. From noon EDT today through late tonight. * IMPACTS. Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. * ADDITIONAL DETAILS. - http://www.weather.gov/safety/flood

* WHAT. Heat index values up to 94. * WHERE. Calhoun, Eaton, Ingham, Jackson, Allegan, Barry, Kalamazoo, Kent, Ottawa, and Van Buren Counties. * WHEN. Until 8 PM EDT this evening. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Southwest winds 10 to 15 knots with gusts up to 25 knots and waves 2 to 5 feet expected. * WHERE. St Joseph to Grand Haven. * WHEN. From 8 PM this evening to 8 AM EDT Sunday. * IMPACTS. Conditions will be hazardous to small craft.

* WHAT. High wave action, strong currents, and dangerous swimming conditions expected. Piers may be heavily swamped by waves. * WHERE. Ottawa, Allegan and Van Buren counties. * WHEN. From this evening through Sunday morning. * IMPACTS. Strong currents can pull swimmers into deeper water and high waves can sweep people off piers.