April 27, 2011 Tornado Outbreak

April 27, 2011 Tornado Outbreak In total, 348 people were killed as a result of the outbreak, including 324 tornado-related deaths across six states and 24 fatalities caused by other thunderstorm-related events such as straight-line winds, hail, flash flooding or lightning.[11][12] In Alabama alone, 238 tornado-related deaths were confirmed by the Storm Prediction Center (SPC) and the state's Emergency Management Agency ] Nearly 500 preliminary local storm reports were received for tornadoes over four days, including 292 in 16 states on April 27 alone.[17] This event was the costliest tornado outbreak in United States history, with total damage reaching $10.2 billion (equivalent to $13 billion in 2022).[18] In 2023, tornado expert Thomas P. Grazulis created the Outbreak Intensity Score (OIS) as a way to rank various tornado outbreaks. The 2011 Super Outbreak received an OIS of 378, making it the second worst and most violent tornado outbreak in recorded history.