The long line of severe storms that swept across the Midwest on Friday – from parts of Nebraska, through Iowa and into Illinois – has been officially classified a derecho by the Storm Prediction Center.
The Center classifies derechos as a wind damage swath that “extends more than 240 miles and has wind gusts of at least 58 mph or greater along most of the length of the storm’s path.”
It signaled the start of what became a severe weather weekend and a 2024 Memorial Day, with dozens of reports of strong winds, rain or hail hitting many parts of the U.S.
“We have obviously seen an absolutely, astronomically high number of severe weather reports over the last month,” says Michael Clark, chief meteorologist for BAMWX.com.
Clark says during May alone, there have been 469 tornadoes, 3,475 severe wind events and 1,640 severe hail events in the U.S. The number of storms reported is one of the highest for the month of May, if not the highest, since 2011. See You Can Now Blame El Niño and La Niña For the Extreme Weather Outbreaks, Planting Delays This Spring
“I’m looking at the map right now, and it’s almost as if every state east of the Rockies has reported a tornado during the month somewhere,” he says. “It’s kind of hard to wrap your head around how much there’s been.”
A Tough Transition Is Underway
While the number of storms this month has been unusually high, their occurrence has been expected meteorologists say, as the country transitions away from an El Niño into a La Niña.
“In spring, whenever you see these transitions, severe weather is amplified quite a bit,” Clark says.
According to the National Centers for Environmental Prediction, there is a 49% chance La Niña develops between June and August, and a 69% likelihood it will be in place sometime between July and September.
Clark and his meteorologist colleague Bret Walts told AgriTalk Host Chip Flory that they are predicting La Niña will be in place sooner than later – likely by July.
“I think that the atmosphere has already been trying to respond to that,” Walts says. “We’ve certainly seen it with this severe weather.”
More Rough Weather Ahead This Summer
Walts believes high winds and big rainstorms will continue throughout late spring and into the summer months. See Iowa Crews Search For Survivors After Deadly Tornadoes
“I’m concerned that as the heat ramps up later on into June and July that we could get more of these derechos going through,” Walts says.
In addition, Walts and Clark are concerned significant heat domes will occur over the Corn Belt and rain events will slow significantly as the second half of the growing season gets underway. See Expect a Hotter Than Normal Summer This Year
“When La Niña sets in, I am under the impression that in the later part of the growing season the moisture will be potentially shutting off,” Clark says. “This happens in big hurricane seasons where that ridge of heat sets up over the northern U.S., over the Great Lakes. It steers hurricanes into the Gulf of Mexico, but it shuts off precipitation in the Corn Belt.
“That’s a concern I have this year,” Clark adds. “These very wet springs with a lot of moisture going into La Niñas historically don’t really turn out to be very friendly the second half of summer.”
The complete weather conversation is available on AgriTalk here:
