November 2013 Tornado Outbreak

Date: November 17, 2013 • Location: Maroa, United States

An outbreak of 77 confirmed tornadoes occurred in seven U.S. states; it became the largest November tornado outbreak in Illinois and Indiana.

On November 17, 2013, the deadliest and costliest November tornado outbreak in Illinois history took shape, becoming the fourth-largest for the state overall. With more than 30 tornadoes in Indiana, it was that state's largest tornado outbreak for the month of November, and the second largest outbreak recorded in Indiana. Associated with a strong trough in the upper levels of the atmosphere, the event resulted in 77 tornadoes tracking across regions of the Midwest United States and Ohio River Valley, impacting seven states. Severe weather during the tornado outbreak caused over 100 injuries and eleven fatalities, of which eight were tornado related. Two tornadoes—both in Illinois and rated EF4 on the Enhanced Fujita scale—were the strongest documented during the outbreak and combined for five deaths. In addition to tornadoes, the system associated with the outbreak produced sizeable hail peaking at 4.00 in (10.2 cm) in diameter in Bloomington, Illinois, as well as damaging winds estimated as strong as 100 mph (160 km/h) in three locations.