INDIANAPOLIS — After several quiet years, tornadoes have erupted in the United States over the last two weeks as a volatile mix of warm, moist air from the Southeast and persistent cold from the Rockies clashed and stalled over the Midwest.
On Tuesday, the U.S. set a new record of 12 consecutive days with at least eight tornadoes, based on preliminary data from the National Weather Service. The previous record for consecutive days with that many tornadoes was an 11-day stretch that ended on June 7, 1980.
“We’re getting big counts on a lot of these days and that is certainly unusual,” said Patrick Marsh, warning coordination meteorologist for the federal Storm Prediction Center.
The National Weather Service received at least 27 more reports of tornadoes Tuesday, suggesting that the record for consecutive days would be broken once the official totals are counted.
The weather service has received 934 tornado reports so far this year, up from the yearly average of 743 observed tornadoes. More than 500 of those reports came in the last 30 days. The actual number is likely lower, however, because some of the reports probably come from different witnesses who spot the same twister.
The U.S. has experienced a lull in the number of tornadoes since 2012, with tornado counts tracking at or below average each year and meteorologists working to figure out why. Marsh said this month’s uptick is rare, but the country saw similar increases in 2003, 2004, 2008 and 2011 that were highly unusual at the time.
He said his agency is trying to determine why the country is seeing another surge in tornadoes after the quiet spell but doesn’t have enough data to confirm whether climate change or other forces played a role. Scientists say climate change is responsible for more intense and more frequent extreme weather such as storms, droughts, floods and fires, but without extensive study they cannot directly link a single weather event to the changing climate.
“From our point of view, there’s nothing we can definitively say as to why we’re in this current pattern,” Marsh said.
