Harold Brooks of the Storm Prediction Center in Norman, Okla., said the last time anything remotely looked like this year was the spring of 1927, which also had a lot of tornadoes and flooding.
The researchers explained that April brought an active weather pattern across the 48 contiguous U.S., with strong storms moving through the center of the country, tapping into moisture from the Gulf of Mexico as they matured across the mid-Mississippi Valley.