From the Poweshiek County Emergency Management Agency:
At approximately 7:36 a.m. on Aug. 20, 2019, the Poweshiek County Sheriff’s Office was notified by a homeowner that they believed their home was struck by a tornado approximately 1 mile southeast of Grinnell in rural Poweshiek County.
On the arrival of authorities, it was discovered that the home, two outbuildings, and several trees all sustained major damage or were destroyed by the storm. Poweshiek County Emergency Management conducted damage assessment on the property and provided a damage report to the National Weather Service – Des Moines.
The National Weather Service was able to look at the debris and damage to the property, nearby crop damage, and radar imagery at the time the homeowner stated the incident occurred. The National Weather Service determined in their survey this was the result of a microburst.
A microburst is a localized column of sinking air (downdraft) within a thunderstorm. The sudden downforce in air can cause severe damage at the surface, as wind speeds can reach up to 100 MPH, or even higher, which is equivalent to an EF-1 tornado. Winds this high can cause major damage to structures, trees, and leave a large scattering debris field.
Two additional area properties also sustained damage as a result of this microburst with damage to a grain bin, and damage to trees and some broken windows. Fortunately, no injuries were reported as a result of this weather phenomenon. It is very important that you take severe thunderstorm warnings just as serious as a tornado warning and seek shelter, as these are common in thunderstorms, but can have even less warning than a tornado.
For more information on microbursts, or other weather related events, visit www.weather.govand for additional weather related safety tips, emergency preparedness planning or to sign up for the Poweshiek County Emergency Notification System, please visit www.poweshiekready.org.