Science impact: Experimental Warn-on-Forecast system yields 75-minute lead time on violent tornado
On May 21, 2024, severe thunderstorms struck central Iowa, producing flash flooding, straight line wind damage and at least nine tornadoes. One of those tornadoes impacted the community of Greenfield, resulting in five fatalities. The tornado was rated an EF4 by the NOAA National Weather Service (NWS), with an estimated wind speed of up to 185 miles per hour.