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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.

Storm surveys have confirmed EF-4 damage in Greenfield, Iowa, EF-3 damage in NW Adams County, and EF-2 damage from two tornadoes: in Polk into Story County and near Arbor Hill. Other tornadoes from the event are also detailed below. 


We appreciate the assistance of emergency managers in assessing the damage across all of central Iowa.


Information from surrounding offices: NWS Quad Cities | NWS Omaha


Information is preliminary and subject to change! Check back for updates.

Page last updated: June 3, 2024 6:05 AM

Tornado over northeastern Adams County moving towards Greenfield.

Photo Credit: Isaac Polanski 

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Power Outages In Iowa as of 630 pm on 5-21-24
Graphic from
Moderate Risk (Level 4 out of 5) on 5-21-24 Expected Hazards for 5-21-24
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