What is a polar vortex?
By Kyle Davis, staff meteorologist, American Family Insurance
As the wind blew across my face as I left the library during the winter of 2007, a sense of pride kept me warm even as all other heat was whisked away. The wind chill: -40° F. Or C. It actually doesn’t matter, the two measurements come together at that point. I knew my time living in Canada could give me some of the coldest weather I would ever see, and that day in Quebec City, I thought, could very well be the coldest day of my life — it certainly was to that point.
I felt like I deserved some sort of recognition for making it through the experience, maybe even a sticker I could put on the back of my car like marathon runners proudly display.
After spending the next several years in the western U.S., including Arizona, my life took a 142° turn, or 167° if you count wind chill. For my wife, a lifelong Phoenix resident, the irony is the change was about 180° degrees, and nothing could be closer to the truth. When we moved to Wisconsin in 2015, a week after getting married, we knew new challenges were ahead, including winter. Though we’ve felt the cold each winter we’ve lived in Wisconsin, none of it compared to the artic plunge of February 2019, which gave both of us — and our young son — the new coldest temperatures of our lives: -27° F, with a wind chill of -50°.
While the polar vortex has always been around, it did not become ingrained in our vocabulary until recently. To picture the polar vortex, imagine a large circulation around the arctic that extends high up into the stratosphere (anywhere from 10 to 30 miles into the sky). When it is strong and fast moving (like a fast moving top spinning on a table), it keeps the cold air locked up where it should be — in the arctic.
However, sometimes the air way above the arctic suddenly and drastically warms and messes up the polar vortex’s flow (like the top as it slows down and begins to wobble), causing it to split, and sending pieces spinning in different parts of the northern globe. This eventually affects the jet stream down below, which drives much of the weather in the U.S. The jet stream starts to meander and bring down extremely cold air from the north.
Most people would probably agree the bitter cold brought on by these events is not pleasant. Are we going to see more of these episodes? This has been the cause of debate recently, and I’m not sure anyone can say for certain.
However, the number of times we’ve seen a weak vortex which leads to cold outbreaks, has actually increased in the last twenty years from about three to seven days a year. While we might see more cold outbreaks, overall we are seeing fewer extremely cold days.
As an example, see the graphic showing number of days in Madison, Wisconsin (firmly entrenched in the usual path of arctic intrusions) when the minimum temperature dropped below -20° F per decade. It was a lot more often in the ’60s, ’70s, and ‘80s.
As a meteorologist and senior weather modeler at American Family Insurance, we made sure those who respond to our customers’ claims were well aware of the recent dangerous conditions.
Frozen pipes, house fires, and traffic accidents are all common dangers in cold weather, and we wanted our people to be ready to serve customers affected by the frigid temperatures. So, as part of our preparation, we sent out company alerts detailing how cold it was going to get and when the cold would set in.
Putting the customer first defines how we work, what we think about, and how we plan. I’m just grateful I can do it in well-heated buildings. Although it may invoke pride, I’ve experienced enough of those record cold days first-hand, thank you.
Kyle is one of many American Family Insurance experts available to speak on a variety of topics.