Iowa tornado leaves at least 7 people dead

• Another person died in the early evening storms in rural Lucas County, KCCI reports.

State of play: Winterset, a town of at least 5,000 people in Madison County, sustained some of the most visible damage from the storm.

• Daytime images from Sunday illuminate the aftermath of crumbled homes and torn-apart basements.

The big picture: "Strong and violent tornadoes" like the one Saturday aren't typical for Iowa in early March, Alex Krull, meteorologist with the National Weather Service in Des Moines, tells Axios.

Our thought bubble via Axios' Andrew Freedman: The storms that struck on Saturday were well advertised, with a tornado watch and warnings in effect. They resulted from a storm that formed from the clash of spring-like warmth and high humidity with a cold, wintry air mass to the west.

The NWS in Des Moines anticipates the tornado will be categorized as at least an EF3, which is not common in early March, Krull says.

• Severe weather is most common in April and May.

Initial reports show that three supercell thunderstorms moving from the Nebraska-Iowa border produced the tornadoes that neared Des Moines on Saturday.

• Surveyors are determining whether one continuous tornado ripped through the area or the thunderstorms produced multiple funnels.

What's next: The NWS office in Des Moines is surveying the damage to determine the intensity of the tornadoes, and plans to provide an update at 7pm local time on Sunday.

Editor's note: This piece was corrected to show officials had said four adults died in Madison County, not six adults.