Twenty-four people died after a tornado struck central Tennessee on March 3, NBC News reported. The incident was the second deadliest in Tennessee’s tornado history, outdone only by a 1952 twister that killed 38 people. Many of us understand tornadoes less than we think.
According to NBC News, the tornado that struck central Tennessee on March 3 killed people in four counties. “The carnage in Tennessee marked the most deadly tornado event in the United States since 23 people were killed in Lee County, Alabama, exactly one year [prior], on March 3, 2019,” the article said. “At least 45 buildings collapsed in Nashville, and police said that there were multiple buildings with damage, primarily in the downtown and the east precincts.”
Despite how common tornadoes seem to be—and that the violent atmospheric storms are taught in schools—most people have never experienced a tornado and often confuse them with other weather phenomena.
“A tornado is defined as a rapidly rotating column of air that is attached to both the base of the cloud and to the ground,” said Professor Eric R. Snodgrass, Director of Undergraduate Studies for the Department of Atmospheric Sciences at the University of Illinois at Urbana-Champaign. “The funnel cloud is visible because it draws cloud water with it—the name ‘funnel cloud’ comes from their shape. They look just like an auto mechanic’s funnel used to pour oil into an engine.”
However, Professor Snodgrass said that tornadoes come in a variety of sizes and shapes. These differences, in addition to suspicious-looking, natural cloud formations, can lead to confusion among the general public, even among meteorologists, in identifying a funnel cloud. Even so, he explained the typical wind speeds and widths of average tornados, information which scientists have gathered from more than 100 years of data from tens of thousands of tornadoes.
“An average tornado is nearly 250 yards wide at its base, [though] some are much smaller—under 100 feet across—while others can stretch well over a mile,” he said. “The average tornado produces winds of 110 miles per hour, while the most powerful tornadoes produce winds three times this speed. An average tornado lasts approximately 10 minutes; during that time, its forward speed is between 20 and 40 miles per hour and its damage track is about four miles long.”
The 1970s: When Tornado Tech Made a Breakthrough
A graph of tornado fatalities by year shows a significant drop-off in the mid-1970s, though it isn’t due to fewer tornadoes.
“Two significant scientific advancements happened in the mid-1970s that revolutionized our ability to warn people of tornadic thunderstorms,” Professor Snodgrass said. “In 1975, the first geostationary satellites were launched to monitor weather. These satellites provided the crucial imagery we needed to assess and forecast the weather.”
Meanwhile, radar technology was advancing. According to Professor Snodgrass, developing radar tech enabled scientists to warn the public several minutes before a tornado would strike a community. These advancements reduced the fatality rate for the subsequent 45 years, and are still doing so today.
“However, even with modern warning systems, live news coverage, social media and a storm spotter network, and 160 Doppler radars, massive tornado outbreaks can still claim hundreds of lives,” Professor Snodgrass said.
The Tennessee twister of March 3 is a sobering reminder of that.
Professor Eric R. Snodgrass contributed to this article. Professor Snodgrass is the Director of Undergraduate Studies for the Department of Atmospheric Sciences at the University of Illinois at Urbana-Champaign, where he also received his master’s degree. Previously, he earned his bachelor’s degree in Geography from Western Illinois University.