Tornado damage threat: considerable or catastrophic?
On May 22, 2011, a column of rotating air spawned a massive EF-5 tornado, with wind speeds greater than 200 miles per hour, over the city of Joplin, Mo. The twister caught the city off guard, leaving 158 people dead and injuring more than 1,000 people, making it the deadliest tornado in the United States since record-keeping began in 1950. As the National Weather Service (NWS) surveyed the city following the tornado, they began considering ideas on how to better alert the public to the risks of dangerous weather events. After a successful test phase of one such idea, the agency is now expanding on its so-called “Impact Based Warnings” experiment.