A phenomenon known as Sudden Stratospheric Warming could lead to some volatile weather in December.
There are several layers in the atmosphere, but the closest layer to the ground is what typically gets the attention. That layer of the atmosphere is called the troposphere and it goes up until the air ceases to get colder with height. Once the temperature starts to increase with height, you’ve reached the stratosphere.
In the stratosphere above the north pole you’ll find the polar vortex, a jet of counterclockwise winds rotating around the north pole. When the stratosphere abruptly warms (sometimes by as much as 50 degrees) the polar vortex becomes displaced and the winds around the poles change direction. This is a sudden stratospheric warming, and it typically leads to the movement of arctic air, taking the cold air locked up near the north pole down closer to the mid-latitudes.
The influx of cold air also leads to a wavier jet stream pattern, which means more precipitation and volatile temperatures.
Here’s what this means for us here at home. During the week of Thanksgiving, milder air will be locked over the eastern US, with cooler air over the west next week. But as our SSW gets underway, our pattern will flip. Colder air will likely spill over the northern and central US. Because of our relatively southern location, there’s no guarantee that we’ll see consistent cold air. We’ll be in the battleground zone between the warmer and cooler air.
This means roller coaster of temperatures, along with higher precipitation and stormier weather.” So as the Sudden Stratospheric Warming event gets underway, expect a more active weather pattern to emerge after thanksgiving.
