Update (6:51 p.m. Saturday, July 23):

The National Weather Service in Des Moines has canceled the head advisory for Story County.

In its cancellation notice the weather service said, areas of cloud and rain to the south helped keep temperatures cooler than expected. Heat indicies in the mid 90s to low 100s are still possible early this evening.

Thunderstorms and cooler weather are expected to spread across central Iowa by mid to late evening.

The National Weather Service in Des Moines has issued a heat advisory for Ames. The advisory goes into effect at 10 a.m. Saturday and continues through 11 p.m. Saturday.

According to the advisory a warm front will bring very warm and humid conditions early on Saturday. A cold front is expected to move through Saturday night into Sunday and bring relief to the state.

Saturday’s high temperature in Ames is forecast at 92 degrees. The heat index could hit the 105 to 110 degree range in the afternoon.