The National Weather Service in Des Moines says a significant storm will impact Iowa by late Tuesday into Tuesday night. Before then, scattered thunderstorms are possible today through Tuesday morning. A few severe storms may develop with this initial activity. The primary system arrives over western Iowa by late Tuesday afternoon.

Severe storm outlook (NWS/Des Moines)

Severe storms are becoming more likely – especially late Tuesday afternoon through mid-evening with tornadoes, large hail and damaging winds all possible. In addition, a significant heavy rainfall event is expected and may result in localized flash flooding and significant rises on area streams and some rivers.

Much colder air will follow the storm by Thursday night. Early morning lows Friday and Saturday are forecast to dip into the 30s in some areas. Highs will only reach the 50s to lower 60s both Thursday and Friday.