* WHAT...For both Heat Advisories, heat index values up to 109.
* WHERE...Portions of central, east central, northern, northwest, southeast, southern, southwest, and western Oklahoma and northern Texas.
* WHEN...For the first Heat Advisory, until 9 PM CDT this evening. For the second Heat Advisory, from noon to 9 PM CDT Thursday.
* IMPACTS...Hot temperatures and high humidity may cause heat illnesses.