EF4 tornado is "very unusual" in Iowa for early March

The powerful EF4 tornado that caused devastation across Winterset and surrounding communities was "very unusual, especially that magnitude," Brad Small, a meteorologist at the National Weather Service in Des Moines, told Axios.

• Most tornadoes occur in April and May in Iowa, but the warm and humid air over the weekend combined with the cold contributed to unstable conditions.

By the numbers: Saturday's violent storm broke a number of records from the last decade:

• The last EF4 tornado recorded in Iowa in March was from 1990.
• Last weekend's tornado was continuously on the ground for 69.5 miles — the longest track in Iowa since 1984, when a tornado went for 117 miles.
• It was the deadliest tornado since 2008, when a storm killed seven people in Parkersburg and two in New Hartford.

The big picture: Clear links between this early-season event and climate change are lacking, according to meteorologist Harold Brooks of the National Severe Storms Laboratory in Oklahoma.

• While studies show that climate change-driven trends may be shifting the region where tornadoes typically occur, like the anomaly in Kentucky last December, it's unclear if Iowa's tornadic event was driven by such.

Axios' climate and energy reporter Andrew Freedman contributed to this report.