DES MOINES, Iowa — A week of violent weather and deadly tornadoes was brought to a close early Friday morning as a massive front of storms barreled eastward across the state.
The line of intense thunderstorms made its way across Iowa starting around 2 a.m., leaving heavy rain, hail damage and brief tornado touchdowns in its wake.
Were Iowa's Friday, May 24 storms part of derecho?
Yes, the more than 500-mile long line of storms was technically a derecho.
Characterized by long-lived, violent storms, the Friday system had all the necessary ingredients to form a derecho's typical hurricane-force winds, flash floods and intense rain.
The thunderstorms sprawled from central Nebraska through Iowa and into parts of Illinois.
What is a derecho?
In general terms, a derecho is a long-lived line of thunderstorms that produces intense wind gusts over a large area.
Specific criteria have to be reached in order to label a storm complex as a derecho:
- The swath of wind damage must extend more than 400 miles, producing wind gusts of 58 mph or greater along most of its length
- It must also include several, well-separated 75 mph or greater wind gusts
- The damage path also needs to be greater than 50 miles wide
When was Iowa's last derecho?
Iowa has experienced a handful of derechos in the past five years. Prior to May 24, 2024, the most recent derecho to impact Iowa occurred on June 29, 2023. The storms primarily affected southeastern Iowa before extending into Illinois and Indiana.
A derecho on July 5, 2022 caused severe thunderstorms to roar from northwest to southeast Iowa. Earlier that year, another derecho affected parts of northwestern Iowa on May 12, 2022.
Potentially the most memorable derechos for Iowans occurred in August 2020 and December 2021. On Aug. 10, 2020, a derecho ravaged the state, producing wind damage across 90,000 square miles, The derecho led to $11.5 billion in damage and four fatalities.
The derecho on Dec. 15, 2021 was the first derecho ever recorded in the United States during the month of December. The derecho was accompanied by a massive tornado outbreak: 63 tornadoes touched down in one day, making it the biggest single-day tornado outbreak in Iowa's recorded history. Event damage from the day topped $1 billion, according to the National Weather Service.
You can view the latest forecast from Local 5 at this link. A full list of storm reports from the National Weather Service is available at this link.