“Devastated to see the destruction from today’s severe storms & tornadoes,” tweeted Iowa Gov. Kim Reynolds (R). “Praying for all Iowans impacted & for the emergency management crews responding tonight.”
The Marshalltown tornado
A “large, violent, and extremely dangerous tornado” entered Marshalltown around 4:37 p.m. Thursday afternoon. The Marshall County Courthouse, built in 1885 and renovated in June 1978, lost its brick clock tower and suffered other damage in the storm.
A storm report filed 10 minutes after the storm passed through the city 50 miles northeast of Des Moines reported “catastrophic damage, including vehicles missing, vehicles overturned, tops of buildings gone, trees down,” and live power lines and gas mains posing a hazard to residents. No injuries have yet to be reported from this particular storm, Weather.com reported.
This tornado originated from two persistent supercell thunderstorms that raced southeastward through central Iowa. The bulk of the activity remained east of Interstate 35.
The storm towered to an incredible 55,000 feet as it swept into the city. A “clear slot” emerged east of the funnel in a region of the storm known as the “vault,” allowing people east of the tornado to stare directly at it.
A “debris ball” — the most sobering radar signature a meteorologist can see — emerged on radar as the tornado tracked through the downtown area. This was the result of debris being thrown more than two miles into the air, tricking the radar into plotting high values. The jagged, unusual shape of the objects swirling around in the funnel showed up as a value of “poor correlation,” suggesting jagged materials unlike rain or hail.
The Bondurant and Pella tornadoes
A second supercell farther south along I-80 featured two tornadoes on the ground at once in the vicinity of Altoona, Bondurant and Valeria, which are about 20 miles northeast of Des Moines. A third funnel may have touched down simultaneously. Motorists along Highway 65 northeast of Des Moines captured the funnels as they barreled eastward.
One of the tornadoes passing near Bondurant was videotaped as it appeared to heavily damage a number of homes. “Houses are being torn to shreds,” the photographer can be heard saying. “Oh, my god.”
Weather.com reported that the twister caused several minor injuries.
The storm went on to cause damage in Pella, Iowa, where Weather.com reported additional injuries at the Vermeer equipment manufacturing plant. Social media footage shows heavily-damaged cars, that were tossed through the air, piled on top of one another, on their sides, and upside down.
This cycling storm system produced another serious tornado just northwest of Oskaloosa. The storm weakened before entering the city. That same storm later reorganized near Ottumwa, producing a rain-wrapped tornado at the airport.
The National Weather Service Storm Prediction Center logged 32 reports of tornadoes through early Thursday evening. If this number increases, it could edge in as the third-worst day of the year for tornadoes, beating out any event in the more traditional “tornado month” of May.
Thanks to the warm atmospheric conditions characteristic of July, hail was not widespread on Thursday. Wind and tornadoes proved to be the main hazards.
A separate set of storms developed into a nasty cluster just west of Kansas City. A wind gust of 89 mph was reported in Lecompton, Kan., by the emergency manager.
More dangerous weather appears to be in the offing Friday. The Storm Prediction Center has outlined regions in the Ohio Valley from western Kentucky down toward Tennessee as having an “enhanced risk” for severe weather. Damaging winds and large hail are likely to the be primary hazards, although tornadoes are possible with any isolated storms that develop.
Social-media footage of the tornadoes in Iowa and the damage they caused is provided below.
Marshalltown tornado video
Tornado video from Altoona, Valeria and Bondurant, about 20 miles northeast of Des Moines
Damage scenes from Marshalltown and Pella