* WHAT. Heat index values up to 97. * WHERE. Portions of central, south central, southwest, and west central Michigan. * WHEN. Until 8 PM EDT Friday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. South winds to 25 kt and significant waves to 4 ft expected. * WHERE. Illinois and Indiana nearshore from Winthrop Harbor IL to Michigan City IN. * WHEN. From 10 AM this morning to 10 PM CDT this evening. * IMPACTS. Conditions will be hazardous to small craft.

* WHAT. Dangerously hot conditions with heat index values between 95 and 105 expected throughout the week. Low temperatures in the 70s at night will provide little relief from the heat. * WHERE. Portions of northern Indiana and northwest Ohio. * WHEN. Until 8 PM EDT Friday. * 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 stress increases with the number of consecutive hot days. While heat indices may be slightly lower today because of cloud cover and chances for showers and storms, hot conditions are forecast again for Wednesday through Saturday. The effects of heat are most impactful for more vulnerable urban populations.

* WHAT. Heat index values of 95 to 100 degrees expected throughout the week. Low temperatures in the 70s at night will provide little relief from the heat. * WHERE. Portions of northern Indiana and southwest Michigan. * WHEN. Until 8 PM EDT /7 PM CDT/ Friday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses to occur. * ADDITIONAL DETAILS. Heat stress increases with the number of consecutive hot days. While heat indices may be slightly lower Today because of cloud cover and chances for showers and storms, hot conditions are forecast again for Wednesday through Saturday. The effects of heat are most impactful for more vulnerable urban populations.

* WHAT. Heat index values up to 100. * WHERE. Portions of central, south central, southwest, and west central Michigan. * WHEN. Until 8 PM EDT Friday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.