* WHAT...Afternoon heat index values will reach or exceed 100 across much of the area, with some locations peaking around 108.
* WHERE...A portion of East Tennessee, primarily in valley locations, will be most likely to approach heat indices near or slightly above 108 during the peak heat of the late afternoon hours.
* WHEN...Until 8 PM EDT /7 PM CDT/ Saturday.
* IMPACTS...Hot temperatures and high humidity may cause heat illnesses.