Peoria, Ill. (WMBD) – The Polar Vortex will NOT be making a visit to Central Illinois next week, but it will be responsible for bringing the region its coldest temperatures of the season. By this weekend, high temperatures in the single digits and teens are expected with low temperatures below zero.
What is the Polar Vortex?
Yes, the Polar Vortex is a real phenomenon. However, over the last 10 years the term has evolved into a clickbaity headline to describe arctic outbreaks and seems to come around every year in the months of January and February.
The term Polar Vortex refers to the counter-clockwise flow of air that bottles up cold air near the North Pole. While the center of that flow wobbles, it never deviates too far from the North Pole. During the winter months the Polar Vortex will occasionally weaken allowing colder temperatures near the arctic circle to drop south in to the United States.
You can think of the Polar Vortex as a spinning top. When the top is spinning fast, the rotation of the top is tight and it doesn’t wobble much. When you disturb the spinning top, it starts to spin slower and the top will begin the wobble…the atmosphere does the same thing. As that counter-clockwise flow slow down, the cold air that’s been bottled up near the North Pole will slosh around and start to advance southward.
In this case, the Polar Vortex has been disturbed by a stratospheric warming event and the counter-clockwise flow around the Northern Hemisphere is beginning wobble. This will send arctic air southward bringing much colder air to much of the U.S.
What does it mean for us?
The first of a series of cold fronts is expected to move through Central Illinois on Thursday. Scattered rain showers are expected ahead of the cold front with temperatures reaching the lower to mid 40s. Once the front comes through, temperatures will drop quickly, reaching the lower 20s by early evening. This could allow for any lingering rain showers to change to snow but no snow accumulation is expected. Instead, the sudden drop in temperatures could result in a flash freeze threat Thursday evening where wet roads begin to ice over.
Quiet weather is expected on Friday before a stronger cold front drops in Friday evening and Saturday. While accumulating snow is possible with this system, the main issue will be the dangerous cold air coming in behind it. A backwards trajectory of the incoming cold air mass shows that the cold air set to impact Central Illinois early next week is indeed near the North Pole.
While the placement of the coldest air is uncertain, high temperatures in the single digits and low temperatures below zero look likely early next week. Very dangerous wind chills in the -10° to -30° range could also be possible.
Be sure to monitor future forecast as the severity of this incoming cold snap is better understood. Be sure you have the proper clothing and necessities to get through the colder weather.