At this hour, it’s still a developing severe weather event in progress, but Iowans might have witnessed the birth of a derecho. A complex of showers and thunderstorms took shape quickly this morning, forming a bowing segment of thunderstorms that produced winds up to 70mph. You can see in the radar image to the left what the storms looked like at their peak here in Iowa. These storms raced from west to east across portions of southern Iowa.
There was damage reported in many areas. Numerous towns reported downed trees and power lines. Unfortunately, there was a report of an injury at Lake MacBride in Johnson County where a tree reportedly fell on a person. It was later confirmed that a woman was killed when a tree fell on the tent she was in. Although we do not know the circumstances that led to her death, this serves as a reminder to ALWAYS be aware of the weather conditions when you are out and about.
To the right you can see the wind and hail events reported to the National Weather Service. The blue dots mark wind reports or damage, the green marks where large hail was reported. As for this potential derecho, if you’ve never heard or seen that word, it describes a long-lived wind producing thunderstorm complex. The bowing structure that passed through Iowa is now pushing across Illinois. If it continues producing damaging wind gusts, it could go down in the record books as a derecho.
This type of event is not exceptionally rare, but certainly interesting to watch and of course, very dangerous because they can impact a large area over several hours. As for the severe weather threat that Iowa faces over the rest of the Memorial Day holiday, we’ll have more on that later today.