* WHAT. Heat index values up to 96. * WHERE. Calhoun, Eaton, Ingham, Jackson, Allegan, Barry, Kalamazoo, Kent, Ottawa, and Van Buren Counties. * WHEN. Until 8 PM EDT Saturday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Dense fog will reduce visibility to less than 1 NM. * WHERE. Calumet Harbor IL to Michigan City IN. * WHEN. Until 10 PM CDT this evening. * IMPACTS. Low visibility will make navigation difficult.

* WHAT. Dense fog will reduce visibility to less than 1 NM. * WHERE. Illinois and Indiana nearshore from Winthrop Harbor IL to Michigan City IN. * WHEN. Until 10 PM CDT this evening. * IMPACTS. Low visibility will make navigation difficult.

* WHAT. Heat index values up to 98. * WHERE. Calhoun, Eaton, Ingham, Jackson, Allegan, Barry, Kalamazoo, Kent, Ottawa, and Van Buren Counties. * WHEN. Until 8 PM EDT Saturday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Dangerously hot conditions with peak heat index values of 95 to 102 through Saturday. 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 Saturday. * 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. The effects of heat are most impactful for more vulnerable urban populations.

* WHAT. Peak heat index values of 95 to 100 through Saturday. * WHERE. Portions of northern Indiana and southwest Michigan. * WHEN. Until 8 PM EDT /7 PM CDT/ Saturday. * 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.

An Air Quality Action Day has been forecast for Northwest Indiana for elevated ozone levels and is IN EFFECT UNTIL MIDNIGHT CDT FRIDAY NIGHT. Ozone Levels are expected to be at unhealthy levels for sensitive groups. For additional information. please visit the IDEM SMOG Watch web site at www.SmogWatch.IN.gov or the EPA AIRNOW web site at www.airnow.gov and click on Indiana.

An Air Quality Action Day has been forecast for Northwest Indiana for elevated ozone levels and is IN EFFECT UNTIL MIDNIGHT CDT THURSDAY NIGHT. Ozone Levels are expected to be at unhealthy levels for sensitive groups. For additional information. please visit the IDEM SMOG Watch web site at www.SmogWatch.IN.gov or the EPA AIRNOW web site at www.airnow.gov and click on Indiana.