The Polar Vortex is a term you might have heard in recent years when unusually cold arctic air blankets the South. It is not a new artifact of weather. Although it is not something new, it has only recently been popularized by meteorologists across the country to explain cold Artic outbreaks.
You will no doubt be hearing about the Polar Vortex on your evening weather forecast this month. It always exists near the Poles, weakening in the summer but getting stronger this time of year.
Let me explain what it is. The term “vortex” refers to the counter-clockwise flow of air that helps keep the colder air near the Poles. During winter, sometimes the Polar Vortex will expand, sending cold air southward with the jet stream. One such outbreak occurred last month when we saw temperatures drop into the low 20s, teens in the mountains.
Debilitating sudden snow storm on I-75/85 in Atlanta.
The one that occurred in January of 2014 brought bone chilling artic air and two inches of snow that paralyzed Atlanta.
There are several things the Polar Vortex is NOT. It not something new. It has always been there but now meteorologists talk about it more, as our viewers have become more “weather savvy.” It is also not a feature that exists at Earth’s surface. We examine the vortex tens of thousands of feet up in the atmosphere.
What we need to know is, is it weakening or strengthening.
You would think a strengthening Polar Vortex means trouble. It is just the opposite. A WEAKENING Polar Vortex allows cold arctic air to spill south. A STRONG vortex keeps the cold air arctic air corralled across the North Pole, like a big fence.
Even when we don’t see ice or snow from these episodes, extremely cold temperatures like we saw is 2015 and in 2021 led to damaged homes and damaged pipes. Georgia’s peach crop really took it on the chin during those winters.
A lesson on Polar Vortex and what it can do
There is also something else we have really begun to understand more in recent years. It is the amount of snow cover across Siberia.
The latest snow cover map from NOAA shows a great deal of snow cover there. That is the source region of where our cold arctic outbreaks come from. Should the Polar Vortex weaken this month, all that really cold air sitting over that snow cover will come down over the United States like an avalanche. We have the technology to detect when this is going to happen. We will have time to prepare for that next event. In the meantime, you now know what it is and what it can do.
I hope all of you have a wonderful new year. Happy 2025!
Photos: courtesy NOAA and Glenn Burns
