This year is expected to pack plenty of tornadoes, according to predictions by AccuWeather.
Even so, the number of tornadoes as of May 6 was much lower than the same time last year, AccuWeather found, with preliminary numbers putting the number of U.S. tornadoes between Jan. 1 and May 1 at 625; for comparison, that same stretch saw 912 U.S. tornadoes in 2011.
While tornadoes occur in many parts of the world, they are most frequent in the United States, with May being a historically active month for twisters. U.S. twisters strike predominantly along Tornado Alley, a flat stretch of land from west Texas to North Dakota. The region is ideal for tornadoes, as dry polar air from Canada meets warm moist tropical air from the Gulf of Mexico.
Tornadoes, which are violently rotating columns of air that extend from thunderstorms to the ground — cause an average of 70 fatalities and 1,500 injuries each year in the United States, according to the National Oceanic and Atmospheric Administration (NOAA).
The strongest of the bunch packs rotating winds of more than 250 miles per hour (402 kilometers per hour), according to NOAA.