Tornado outbreak of March 17–18, 1925

From March 17–18, 1925, one of the deadliest tornado outbreaks in recorded history generated at least 12 significant tornadoes and spanned a large portion of the midwestern and southern United States. In all, at least 751 people died, including men, women, and children. 2,298 were injured, making the outbreak the deadliest tornado outbreak in U.S. history. The outbreak generated several destructive tornadoes in Missouri, Illinois, and Indiana on the same day, as well as significant tornadoes in Alabama and Kansas. In addition to confirmed tornadoes, there were undoubtedly others with lesser impacts, the occurrences of which have been lost to history.

The outbreak included the Tri-State Tornado, the deadliest disaster in Illinois, the deadliest tornado in U.S. history, and the second-deadliest registered in world history. The 219-mile-long (352 km) track left by the tornado, as it crossed from southeastern Missouri, through southern Illinois, and then into southwestern Indiana, is also the longest ever recorded. Modern meteorological re-analysis has suggested that the extremely long path length and lifespan reported in historical accounts are perhaps more plausibly attributed to multiple independent tornadoes belonging to a tornado family, rather than a single, continuous tornado. Although not officially rated by NOAA, the Tri-State Tornado is recognized by most experts (such as Tom Grazulis and Ted Fujita) as an F5 tornado, the maximum damage rating issued on the Fujita scale.

Background

During a six-year review study of the Tri-State tornado published in 2013, new surface and upper air data was obtained and meteorological reanalysis was utilized, adding significantly to knowledge of the synoptic and even mesoscale background of the event.