Could the southern snowstorm indicate a delayed, more severe tornado season?
The severe winter weather that hit the southern United States area is leading some meteorologists to believe it could mean not just a delayed tornado season, but one that is more severe.
While peak severe weather typically runs from March through May, increased storms have recently been tracked across the plains starting in the middle of winter and early spring.
“The last couple years, it was an early start to tornado season," said Reed Timmer, an extreme meteorologist in AccuWeather's spring preview. "We were already chasing during parts of January last year. That's because there were El Niño conditions in the tropical Pacific, so we had a very energized southern stream to the jet that was pumping moisture, bringing with it disturbances as well, early on in the year."
"There was a lack of true arctic, stable air in mid-to-late winter last year," said Paul Pastelok, AccuWeather lead long-range meteorologist.
This spring the weather may play out differently due to an influx of Arctic air, and a La Niña that is expected to influence weather patterns across the globe.
What's La Niña's impact on tornado season?
Though every La Niña is different, the pattern in 2021 is similar to that of February 2011. That system produced over 700 tornadoes in total with 343 of those coming from a super outbreak that took place across the southern, midwestern, and northeastern portions of the United States from April 25-28. Four of those were rated EF5.
In total, the three-day system left behind more than 300 fatalities, and over 2,800 injuries, and approximately $10 billion in damage
"During February and March of that year, everyone was wondering if it was going to be a very below-average year and then the bottom dropped out in April," Timmer said.
Similarly, the 2021 season may have a slow start with increased activity during April and May, where the recent clashes of extremely cold air from winter storms across the country, and warmer air from the south have set the atmospheric stage for potentially destructive tornados.
Though an analog model may not present a full picture.
Dr. Patrick Marsh, chief of the Science Support Branch NOAA/National Weather Service Storm Prediction Center, said comparing one season to previous seasons works until it doesn't.
"They're basically saying, 'the last time we had air like this was 2011', " Marsh said
"Regarding 2011, I know a lot of people are making references to that because 2011 was the last we arctic air outbreaks similar to this," he said also pointing out that while it was an active season, he would not call it delayed.
"Just because we've had two weeks of bitter cold doesn't mean it will take the atmosphere months to recover from it," Marsh said. "So I'd be hard-pressed to say that because of this we'd have an active but delayed severe weather season."
He does point out that it doesn't mean there won't be localized threats, some of which have already occurred.
On Sunday, Feb. 14, an EF0 tornado touched down in a Tampa, Florida retirement community. One day later, an EF2 dropped on Damascus, Georgia.
"What I can say is that if you are hit by a tornado it doesn't really matter if it was an active season or not. It's active to you," Marsh said.