Major tornado outbreak sequences occurred in the United States in May 1917, 1930, 1949, 1965, 1974, 2003, and 2011. Another exceptional outbreak sequence apparently occurred during mid to late May 1896. Although some days lacked tornado outbreaks, the period from mid to late April 2011 and late May 2019Scientists forecasted late May tornado outbreak nearly four weeks before it ripped through U.S. also were periods of especially high tornado activity.
