Gallery of March 31 At 5 P & Key Facts

A widespread, deadly, and historic tornado outbreak affected large portions of the Midwestern, Southern and Eastern United States on March 31 and , the result of an extratropical cyclone that also produced blizzard conditions in the Upper Midwest. The Storm Prediction Center (SPC) issued a rare high risk for severe weather in two areas of the Mississippi Valley on March 31, the first high risk issuance since . Approximately 28 million people were placed under tornado watches, including multiple PDS tornado watches, from the evening of March 31 through the overnight hours into the morning of April 1. This included the Little Rock, St. Louis, Chicago, and Memphis metropolitan areas, all of which were hit by multiple rounds of severe squall lines and supercell thunderstorms that produced damaging winds, large hail, and tornadoes. EF3 tornadoes in Arkansas, Tennessee, and Illinois prompted the issuance of tornado emergencies and multiple mass casualty incidents were declared for some of the hardest hit areas. One of these tornadoes was a high-end EF3 tornado that passed through the northern Little Rock metro, causing extensive damage and dozens of injuries. The strongest tornado was a low-end EF4 tornado that swept away homes on the west side of Keota, Iowa. The Apollo Theatre in Belvidere, Illinois collapsed during a concert due to an EF1 tornado, injuring up to 40 concertgoers and killing one. Severe and tornadic weather also affected the Northeastern United States in the afternoon and evening of April 1, including a rare EF3 tornado that caused a death in Sussex County, Delaware. At certain points of the outbreak, over 20 simultaneous tornado warnings were active, with a total of 175 tornado warnings issued on March 31 with an additional 51 issued on April 1.In all, 146 tornadoes touched down; 115 occurred on March 31 alone. The outbreak ranks third worldwide for producing the most tornadoes in a 24-hour period, with 136 tornadoes occurring between 19:00 UTC March 31 19:00 UTC April 1. That tally is surpassed only by the 1974 Super Outbreak with 148 in that 18-hour outbreak and the 2011 Super Outbreak with 219 in its busiest 24-hour period, although both of those outbreaks were far more prolific in the number of significant tornadoes produced. This was also the most tornadoes in an outbreak since the 2011 Super Outbreak. Tornadoes killed 26 people during the outbreak, along with one indirect tornado-related fatality. Six other weather-related fatalities took place: five from straight-line winds and one indirect fatality during cleanup. Additionally, over 218 injuries also occurred during the outbreak. Later in the year, tornado expert Thomas P. Grazulis published the outbreak intensity score (OIS) as a way to rank outbreaks. The outbreak received 129 OIS points, ranking it as a historic tornado outbreak.