The Storm Prediction Center of the National Weather Service confirms it was a derecho that blasted across eastern Iowa on Tuesday morning. The powerful storm continued into Illinois and Indiana, where winds topped off at 99 miles an hour.
Damage in Iowa is still being assessed, though it’s reported Clinton and Jackson counties were hardest hit, including near the town of Maquoketa. Also, three EF1 tornadoes are confirmed during the storm, all in Delaware County.
Meteorologist Tyler Ryan, at the National Weather Service in metro Des Moines, says a derecho is a wide-spread, long-lived thunderstorm.
“Typically, they’re extremely powerful because they will produce significant wind damage along some of the leading edge of some of those showers and storms,” Ryan says. “By definition, if the wind damage swath extends more than 240 miles, and it includes wind gusts at least 58 miles per hour or greater along most of the length, then that may be classified as a derecho.”
It was six years and one day earlier a massive derecho caused widespread damage in Iowa and six other states.
“Storms don’t follow dates and sometimes they can land on important dates, but it’s summertime, it’s August. It’s not necessarily out of the realm,” Ryan says. “We typically see maybe one to two derecho events in a year, so it just happened to fall around a time that a lot of people do remember.”
The derecho on August 10th of 2020 was extremely destructive, shredding more than half of the tree canopy in Cedar Rapids with winds of 140 miles an hour. Millions of Midwesterners were impacted by the damage and power outages. The overall cost was estimated at $11-billion and clean-up lasted more than a year in some communities.