* WHAT. Heat index values of 100 to 104 degrees are expected at times this week with variability each day due to clouds and scattered showers and storms, especially early in the week. * WHERE. Portions of north central, northeast, and northwest Ohio and northwest Pennsylvania. * WHEN. Until 8 PM EDT Friday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Heat index values up to 100. * WHERE. Portions of east central Ohio, northwest, southwest, and western Pennsylvania, and northern and the northern panhandle of West Virginia. * WHEN. Until 8 PM EDT Friday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses. * ADDITIONAL DETAILS. Although afternoon thunderstorms have provided cooling relief across many parts of the region, a return to hot and humid conditions will again return on Tuesday and continue throughout the week.

* WHAT. Heat index values up to 100 expected. * WHERE. Central Pennsylvania. * WHEN. From noon Tuesday to 8 PM EDT Thursday. * IMPACTS. Hot temperatures and high humidity may cause heat-related illnesses. * ADDITIONAL DETAILS. The heat wave is expected to continue into the weekend with the hottest temperatures of the summer so far. The longevity of the heat wave has not been experienced in decades during the month of June.