Tornadoes and severe thunderstorms kill people and damage property every year. Estimated U.S. insured losses due to severe thunderstorms in the first half of 2016 were $8.5 billion. The largest U.S. impacts of tornadoes result from tornado outbreaks, sequences of tornadoes that occur in close succession. Last spring a research team led by\u00a0Michael Tippett, associate professor of applied physics and applied mathematics at\u00a0Columbia Engineering, published a\u00a0study\u00a0showing that the average number of tornadoes during outbreaks\u2014large-scale weather events that can last one to three days and span huge regions\u2014has risen since 1954. But they were not sure why.In a new\u00a0paper, published December 1 in\u00a0Science\u00a0via First Release, the researchers looked at increasing trends in the severity of tornado outbreaks where they measured severity by the number of tornadoes per outbreak. They found that these trends are increasing fastest for the most extreme outbreaks. While they saw changes in meteorological quantities that are consistent with these upward trends, the meteorological trends were not the ones expected under climate change.<\/p>\n","protected":false},"author":0,"featured_media":0,"template":"","meta":{"_acf_changed":false,"footnotes":"","_links_to":"","_links_to_target":""},"class_list":["post-2181645","news","type-news","status-publish","hentry"],"acf":[],"yoast_head":"\n