NASHVILLE, Tenn. (WKRN) – When it comes to winter weather, there’s nothing that gets people more excited than talk of a big snow, and it’s been a while since we have seen a widespread large snow in Middle Tennessee and Southern Kentucky.
But scientists announced last week that there has been a warming of the upper atmosphere over the arctic circle that often leads to large scale winter weather events several weeks later, including snow.
It’s called “stratospheric warming”, and every once in a while during the winter, it happens over the North Pole and the Arctic Circle in the layer known as the stratosphere.
“A stratospheric warming event occurs in the atmosphere high above, near where a plane flies and a little bit higher than that; that’s the level of the atmosphere we are talking about,” explained Dan Hawblitzel, the Nashville National Weather Service Office’s Science Information Officer. “It could warm as much as 50°C, even warmer than that.”
“So, when that happens, the jet stream, also known this time of the year as the Polar Vortex, typically resides up in Canada near the Arctic. When the temperatures up near the Arctic in the stratospheric level warm-up, that allows that jet stream to sag quite a bit further south than it otherwise would, and that could allow it to even reach this far south,” said Hawblitzel.
And yes, it could lead to a major snow in parts of the United States, even the mid-south.
“When the jet stream comes into your area, that’s when you want to start watching out for a very active weather pattern,” said Hawblitzel. “And with that jet stream coming this far south, it means it’s bringing cold temperatures with it. So, an active weather pattern, cold temperatures, we know what that spells around here. That spells the potential for winter weather.”
And Hawblitzel gave an example of a stratospheric warming event over the arctic that brought a major snowstorm to the mid-south.
“One of the last significant ones that we had was in January of 2016,” Hawblitzel pointed out. “And those of you who lived in Middle Tennessee around that time might remember that is the last time we received significant snow across a wide area around Middle Tennessee. Parts of Nashville saw seven inches, even more snow, from that stratospheric warming event. That’s not to say that that’s exactly what’s going to happen this time, but it definitely goes to illustrate that that kind of weather is possible in or around Tennessee.”
So keep an eye out toward the end of this month. Somewhere in the United States, possibly even the mid-south could see a major snowstorm.