Another round of early morning heavy rain and possibly severe storms is expected to hit Central Iowa by early Tuesday morning. The Storm Prediction Center has placed Central Iowa under a Slight Risk area for severe storms both for overnight tonight and tomorrow morning. This complex of storms will bring heavy rainfall, strong winds and hail as the primary threats. The threat for large hail will be the initial issue and then the turns to a damaging wind concerning as the complex moves southeast across the state.
A shortwave from over Wyoming will cross South Dakota today and tonight. As it comes into Northern Iowa, it will cause a complex of storms to form late tonight after midnight. Those storms will then move southeast across parts of North Central, Central and Eastern Iowa from 3 AM through 8 AM Tuesday morning.
The storms will follow along a warm front draped from northwest Iowa through southeast Iowa. There will be increasing moisture transport into Iowa plus warmer air advecting into the state to support this complex of storms. Forecast soundings of the atmosphere show drier air in the upper levels which could lead to a potential for strong to severe downdrafts out of the thunderstorm complex.
The complex of storms will exit southeast Iowa by 9 AM Tuesday morning with conditions becoming hot and humid with highs in the low 90s and dewpoints in the 70s. This will lead to heat index values Tuesday afternoon near or at 100 degrees.