Skip to Content

(Project: Blizzard) Demystifying the ‘Polar Vortex’: what it is and how it brings biting cold

ROCKFORD (WREX) — Imagine yourself watching television in the dead of January. You hear the meteorologist on the nightly news use the term "polar vortex", not fully knowing what it means. The impact of the polar vortex is soon to be felt, as temperatures plummet.

The fundamentals:

At both North and South Poles, there exists a large low pressure area. Within these distinct areas of low pressure, some of the coldest temperatures on the planet exist. Counterclockwise flow around these low pressure centers keep the cold air locked away at the poles.

During the winter months in the Northern Hemisphere, the jet stream can become less stable. According to the National Oceanic and Atmospheric Administration, the buckling of the jet stream leads to cold air spilling out of the far reaches of Canada and into the Central United States.

Is this something new?:

Contrary to how it might seem, the 'polar vortex' is not a new atmospheric phenomena. In fact, the first use of the term is believed to date back to the 1850s.

As temperatures plunge, cold air spills into the Upper Midwest.

The polar vortex never goes away, as the poleward low pressures tend to be pretty permanent. This is thanks to the fact that the low pressure is actually located in the upper reaches of the atmosphere and not close to the ground.

What are the impacts?:

Do you remember the last week of January 2019? If not, temperatures plunged well below-zero! Record cold temperatures were recorded multiple days during the last week of January. An all-time cold temperature was recorded in Rockford at -31°. Wind chills during this time dipped to 50° below zero, causing life-threatening conditions for people under-prepared for biting cold. As a result, at least twenty people were killed as temperatures plunged below-zero and stayed there for days on end.

Justin Ballard

Justin Ballard joined 13 WREX as the weekday morning meteorologist. He’s a proud graduate of UNC-Charlotte and happy to call Rockford home.

Skip to content