Much of Iowa is included in a slight risk area and an enhanced risk area from the Storm Prediction Center this Monday. It will be a warm and humid day today with highs in the mid to upper 80s. There may be a few isolated showers and storms in northern Iowa during the afternoon, but the main line of storms is expected to move through the state later tonight.
Continued sunshine through the day will lead to heating of our atmosphere and de-stabilization. We have high dewpoints and a good amount of atmospheric moisture. An incoming cold front from Minnesota and the Dakotas will drop into Northern Iowa late this afternoon. The arrival of the front will bring lifting and upper-level shear to the atmosphere to get the dynamics going to lead to the development of storms in southern Minnesota and northern Iowa. Large hail may be a problem with the storms as they first begin. There may be some rotating updrafts but the tornado threat is minimal as the low-level shear is expected to be low.
The storms are expected to develop into a line that will drop into Central Iowa during the evening. This line of storms may transition to more of a damaging wind threat through Central and Eastern Iowa late tonight. Heavy rainfall is also a concern with 2 to 3” inches possible in a short amount of time with some of the storms. The ground is on the dry side so the rain should be able to be soaked in more so than if we had moisture-laden soils.
High pressure builds in on Tuesday with a return to sunshine and 80s.