EF2 tornado in Polk County, Iowa

This was a long track tornado which started just to the southwest of the Johnston High School with fascia and soffit damage to houses along Catalina Drive. The tornado blew windows out of the high school and continued to produce tree and minor roof damage through the Ashton Point neighborhood. The tornado crossed Camp Dodge and blew down a tree along NW Beaver Drive before crossing Saylorville Reservoir. The tornadoes path took it between Polk City and Ankeny with EF0 damage to trees and houses along Highway 415 and NW 44th Street. The damage began to intensify as the tornado moved northeast with EF1 damage becoming more prevelent in neighborhoods south of Alleman. The first EF2 damage was found on 142nd Avenue just west of Interstate 35 with additional EF2 damage to several houses near the intersection of NE 150th Avenue and NE 29th Street on the east side of the Interstate. The path continued to widen with additional damage near the border with Story County. This tornado moved into Story County near the intersection of NE 42nd Street and NE 166th Avenue. This tornado produced two injuries in Polk County.

PLEASE NOTE, for hail, wind, heavy rain and flooding, please see separate Storm Data entry for May 20-22.

Numerous tornadoes occurred on this day with numerous injuries and four fatalities at Greenfield in Adair County.

Multiple rounds of thunderstorms brought torrential rainfall, damaging winds, hail and destructive tornadoes to the state. These thunderstorms were the result of a low pressure system which lifted north into the area on the night of May 20th, 2024, producing slow moving storms that dropped 2 to 4 inches of rainfall. This resulted in flash flooding over portions of northern and central Iowa through the morning of May 21st, 2024.

Following the heavy rainfall through the morning, skies cleared out ahead of an approaching cold front. By the afternoon hours of May 21st, 2024, this cold front produced a line of strong thunderstorms which produced multiple strong tornadoes throughout the state, including one which led to significant damage in the town of Greenfield, IA, among other locations. This line of storms also produced damaging winds, leading to widespread tree damage and power outages throughout the forecast area.