Tornado Season is in Overdrive – And You May Be In Its Path
Since the 1950s, the annual number of tornadoes in the United States has held fairly steady. But this year has been breaking all the rules – why has there been such a spike in large tornado clusters?
So far, 2019 has seen 935 reported tornadoes in the U.S. – up from an average of 743 from 2005-2015. This has culminated most recently in a rash of tornadoes at the end of May, which caused widespread damage in the Dayton, OH region, knocking out power to some 68,000 households and ranking as the fourth most active tornado day of the year, according to NOAA.
But last year was comparatively quiet, becoming the first year since 1950 (when record keeping started) that there were no “violent” tornadoes (those with estimated wind speeds of at least 166 mph).
So what’s the cause of this recent paradigm shift? Climate change is driving at least part of the change. As ocean and surface temperatures increase, atmospheric instability moves warm, moist air into the middle of the country, providing fuel for thunderstorms and developing tornadoes.
But there were also hints that big numbers of tornadoes were on their way back in April, based on a phenomenon known as the Madden-Julian oscillation, a swing in temperature and moisture that originates over the Indian Ocean and can vary week to week. This year, researchers saw a significant increase in this activity, leading them to predict the high likelihood of tornado activity.
While several factors are contributing to the increase in tornadoes in the U.S., an important thing to pay attention to is where they’re popping up – because Tornado Alley – traditionally spanning Kansas, Nebraska, Oklahoma, South Dakota, and Texas – is shifting east (which is how Dayton, OH’s recent spate has gotten such attention).
In other words, if you thought you were safe geographically from tornado destruction, it’s time to rethink that attitude.