The 2020 tornadoes gave Middle Tennessee a firsthand look at just how powerful and destructive the wind can be. With tornado season now underway, should residents expect one of these strong storms every year?
That’s a difficult question to answer for even the top meteorologists in the region.
The average number of tornadoes that touch down in Middle Tennessee per year is 17. However, that number can be misleading.
“It does vary year to year,” said Caroline Adcock, meteorologist with the National Weather Service in Nashville, on Monday’s episode of This Is Nashville. “Pretty much 2021 and 2022 were complete opposites of one another. So in 2021, Middle Tennessee actually saw 46 tornadoes, whereas in 2022, we only saw one.”
Instead of predicting a certain number of tornadoes, meteorologists look at overall trends.
“It’s difficult to predict each year to year. I know there’s overall trends we can look at just thinking maybe this year might be more active. But, they’re just trends. It doesn’t necessarily mean that year’s going to 100% be more active,” Adcock said.
More: Preparing for Middle Tennessee’s next tornado
However, the trends do indicate that there’s been an increase in the number of recorded tornadoes touching down in Middle Tennessee.
“In the past 30 years, we’ve seen more tornadoes across Middle Tennessee,” Adcock said. “But I want to put a big asterisk next to that because, while we’ve seen more tornadoes, we’re not saying that there’s actually been more tornadoes. … So while we have seen this trend of more tornadoes, it could be simply related to having better technology to identify tornadoes and also more people that can be impacted by them.”
The question of climate change
When asked if climate change could be contributing to the increase in tornadoes, Adcock noted that it’s impossible to blame any one tornado on climate change by itself.
“But what we do know with climate change is that we are seeing more extreme weather events across the U.S,” she said.
Meteorologists and climate scientists have seen tornadoes change over the last few decades. Tornado outbreaks are more frequent, and tornado alley is shifting eastward to include parts of Alabama, Mississippi, Arkansas, Tennessee and other southern states. However, because tornadoes are brief and localized, they’re “difficult to link to global climate trends,” according to Yale Climate Connections.
Tennessee is currently experiencing the La Niña pattern, which means warmer and wetter weather.
“We’ll usually have an earlier and more active severe weather season,” Adcock said.
La Niña doesn’t guarantee a busy tornado season, however.
“When it comes to forecasting tornadoes, we need a lot of variables to come together. We need moisture. We need something called instability — so how fast the air is moving aloft and different things like that. Usually, we need a cold front and different things like that,” Adcock said. “But the really interesting thing with tornadoes is we need all of these variables to come together pretty much perfectly. So even if there’s one little thing off, a tornado might not happen.”
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