It was a terrible day of weather across Iowa Tuesday, May 21. All types of severe weather were experienced including several tornadoes. The worst hit area was the small town of Greenfield in Adair County. At approximately 3:45 PM, Tuesday afternoon, a powerful tornado blasted through the southeast side of the city causing extensive damage. The strength of the tornado is still unknown, but given the damage, some meteorologists estimate it as an EF3 or EF4. This was considered a "long-track tornado" that may have been on the ground for 40 miles or more.
Another tornado tracked from Saylorville Lake and the Polk City area into southern Story County near Zearing. There was also damage reported from this one including some semi trailers that were flipped on the I-35.
Other areas that may have missed the tornadoes where impacted with damaging straight line winds. At one time, more than 65,000 customers were without power across Iowa.