April 18, 2024

Derecho skims Union County, slams Iowa

By SARAH SCULL

Wind storm: Crews work to clear the road after a gust of wind brought down a large branch of a tree across Highway 34 Monday. A truck struck the tree after it fell. No injuries were reported. (CNA photo)

After a storm that saw wind gusts of up to 90 mph in central Iowa, many Iowans across the state were left without power, with structure damage to their homes and businesses, and branches and trees to remove before reopening roads.

The storm was classified as a derecho by the National Weather Service – a rare a straight-line wind storm that can cause heavy rain, flash flooding, hurricane-force winds and tornadoes.

“It’s a wide-spread, fast moving squall line and it can travel a very long distance and it can cover a really big area,” said Justin Glisan, state climatologist.

Glisan described a squall line as a line of thunderstorms forming along or ahead of a cold front. He said Monday’s derecho started in Nebraska, consolidated as it moved across the Iowa border, and bowed out once it entered the state.

“When it’s bowing out like that, what it’s actually doing is drawing in air from behind and that air reinforces the squall line and it almost makes it self perpetuating. That’s why it can go long distances,” Glisan said.

According to the National Weather Service, the derecho traveled 770 miles, from South Dakota and Nebraska to Ohio in 14 hours.

Some of the hardest hit areas were Boone, Story, Marshall, Dallas, Polk, Jasper, Benton and Linn counties, with silos appearing to have been crumpled or collapsed, branches and fence boards penetrating buildings, flattened fields, collapsed buildings and over-turned trailers. The Animal Rescue League of Iowa assisted with the rescue of 1,738 piglets after the trailers transporting them overturned on I-35. Today, MidAmerican reported thousands of its customers were still without power, and as of 9:23 a.m. today, 406,044 Iowans, mostly in central and eastern Iowa were still without power, according to www.poweroutage.us.

Union County Emergency Management Director Joe Duckworth and Union County Sheriff Deputy Daniel McNiell both said few reports were recieved from county residents. During the weather event, some Union County residents reported power outages and electronic communication distruptions attributed to the high winds, but most were back up by early evening. Some reports were received by the CNA of damage to siding and minor structural damage due to fallen or blown branches and trees.

“They are very extreme events and they don’t happen that often, but this one was a pretty severe one,” Glisan said.