ST. LOUIS - Thursday is set to be mild, the typical norm for mid-August, before the heat returns on Friday.

We do get a bit of a break from the thicker humidity Thursday afternoon now that the weather is driven by a zone of high pressure in the Great Lakes, which is aiding in a cooler, northerly mid-level flow.

The cooler weather will be short-lived because the cold front that passed through the bistate on Wednesday will retreat to the north overnight, transforming into a warm front. This will result in more heat and humidity returning Friday into early week.

We are currently below the Heat Advisory criteria, but we are approaching that threshold. Afternoon temperatures will top out in the low to mid 90s Friday into the weekend and a return of the humidity will result in heat index values each afternoon ranging from 100-104 F. This pattern looks to break by mid-week.

Rain will be hard to find for the next few days. A few isolated showers may be in the picture Thursday afternoon for areas in southeastern Missouri more closely tied to the front. The chance of rain on Thursday is very low, but it is not zero.