Deadly Greenfield tornado rated EF-4 with highest winds of 2024 yet

At least five people were reported to have been killed during the tornado that struck parts of Adams, Adair and Page counties. Nearly two dozen fatalities have been tied to tornadoes in 2024 across the country.

GREENFIELD, Iowa – A severe weather outbreak that spawned supercells across the Plains and Midwest on Tuesday is believed to have produced the strongest tornado of the year to impact the U.S., with estimated winds of 175-185 mph, according to the National Weather Service.

Meteorologists with the NWS office in Des Moines determined that damage in the hard-hit community of Greenfield, Iowa, about 60 miles outside of the state capitol, was consistent with a devastating EF-4.

At least five people were reported killed, and dozens of homes were destroyed during the twister’s 44-mile trek through southwestern and central Iowa.

Tornadoes are assigned a rating by meteorologists from 0 to 5 on the Enhanced Fujita Wind Scale, with 0 being the weakest and 5 being the strongest.

Before the most recent designation, there were only two other EF-4s reported in 2024, both occurring in Oklahoma during the spring.

Most tornadoes are rated as either an EF-0 or EF-1 and account for the majority of the 1,300 twisters that strike the country every year.



Meteorologists previously said the damage was consistent with at least an EF-3, but after reviewing the structures destroyed in Adair County with engineers, they determined that the twister actually caused EF-4 damage.

"We got together with the structural engineers and experts in the field and discussed the damage that occurred within Greenfield and along the entire path. Some of the significant damage that occurred in Greenfield after further evaluation of structures, we decided to bump the rating," the NWS said.

An EF-4 has winds of 166-200 mph, meaning the tornado that struck Hawkeye State was only about 20 mph shy of becoming an EF-5.

The last EF-5 to have struck the country occurred back on May 20, 2013, when a powerful supercell devastated the community of Moore, Oklahoma.

Twenty-four people were killed and hundreds injured when the tornado tore through communities south of Oklahoma City.


Oklahoma tornado previously held the record for year’s strongest

Before the Greenfield, Iowa, tornado, the year’s strongest twister was an EF-4 that struck Barnsdall, Oklahoma, on May 6.

The tornado is believed to have killed two people as winds topped 180 mph during a multi-day severe weather outbreak.

Barnsdall, Oklahoma, is located about 40 miles outside of Tulsa and has about half the population of Greenfield.

The spring severe weather season has been active, which is likely the result of the decaying El Niño in the Pacific.

According to reports from the Storm Prediction Center, the year’s preliminary tornado count is running about 32% above average, with the bulk of activity occurring from late April through May.

Despite the uptick in tornadoes, fatalities have not followed, with 22 being reported through the first five months of the year.

Not including circumstances in Iowa, most of the fatalities have occurred in mobile homes, which is one of the worst places to be during a tornado.