* WHAT. For the Heat Advisory through Monday evening, heat index values up to 105 to 110 degrees are expected. For the Excessive Heat Warning on Tuesday, dangerously hot conditions with heat index values in excess of 110 degrees are expected. * WHERE. Portions of central, eastern, north central, southwest, and western Arkansas. * WHEN. For the Heat Advisory, until 8 PM CDT this evening. For the Excessive Heat Warning, from noon to 8 PM CDT Tuesday. * IMPACTS. Heat related illnesses increase significantly during extreme heat and high humidity events.

* WHAT. For the Heat Advisory through Monday evening, heat index values up to 107 degrees are expected. For the Heat Advisory on Tuesday, heat index values up to 107 degrees are expected. * WHERE. Portions of north central, southeast, southwest, and western Arkansas. * WHEN. For the Heat Advisory through this evening, until 8 PM CDT this evening. For the Heat Advisory on Tuesday, from noon to 8 PM CDT Tuesday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Heat index values from 105 to 109 expected. * WHERE. Portions of central, north central, southeast, southwest and western Arkansas. * WHEN. From noon today to 8 PM CDT this evening. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses to occur.

* WHAT. Dangerously hot conditions with heat index values from 110 to 114 expected. * WHERE. Portions of central, eastern, north central, southwest and western Arkansas. * WHEN. From noon today to 8 PM CDT this evening. * IMPACTS. Extreme heat and humidity will significantly increase the potential for heat related illnesses, particularly for those working or participating in outdoor activities.

* WHAT. Heat index values up to 110 expected. * WHERE. Portions of southeast Arkansas, northeast Louisiana, and central and south Mississippi. * WHEN. From 10 AM this morning to 8 PM CDT this evening. * IMPACTS. High temperatures and high humidity may cause heat illnesses.