Tornadoes in the United States
The Midwestern states are very prone to tornado activity, as they are part of "Tornado Alley." States included in the area that are hit by tornadoes the most are Oklahoma, Kansas, Missouri, Nebraska, Iowa, and South Dakota. The Midwestern States are often hit by tornadoes during the late spring and early summer months, especially the months of May and June. This is due to the aforementioned air mass moving northward into the Midwest and combining with another air mass that move southward from Canada. This creates unstable air, creating the potential for storms to strike the most during these months. The frequency begins to decrease in the middle of the summer, as the air mass moves northward into the Great Lakes states.
Indiana
In a 2012 report, Indiana was ranked eighth in a list of the top 20 tornado-prone states based on National Weather Service data from 1950 through 2011. A 2011 report ranked South Bend 15th among the top 20 tornado-prone cities in the United States, while another report from 2011 ranked Indianapolis eighth. Despite its vulnerability, Indiana is not a part of tornado alley.