Tornado Alley
States such as Missouri, Iowa, Minnesota, Wisconsin, Illinois, Indiana, and western Ohio are sometimes included in Tornado Alley. Research suggests that tornadoes are becoming more frequent in the northern parts of Tornado Alley where it reaches the Canadian prairies.
List of tornadoes in the May 2004 tornado outbreak sequence
The Hallam, Nebraska tornado outbreak on May 22 produced nearly 60 tornadoes across mostly Nebraska and Iowa including an F4 that tore through the town Hallam situated halfway between Lincoln and Beatrice. It was recorded as the largest tornado ever with a width of and one person was killed. However, in May 2013 it was passed by the El Reno, Oklahoma tornado with a width of 2.6 miles wide. On May 24, another tornado outbreak took place across the central United States, with about 50 tornadoes confirmed in Kansas, Illinois, Nebraska and Missouri. One person was killed in western Illinois near Winchester west of Springfield. A smaller outbreak on the May 27 produced a damaging tornado in the city of Lexington in northern Kentucky.