The weather will be turning cold this week as air sourced in from the Arctic region drops into the Northern Plains of the U.S. It will be a relatively typical January cold snap for our region. Some will refer to it as a Polar Vortex. Please don't. It isn't.
The Polar Vortex is a high-altitude circulation around the Polar region at approximately 60 degrees north latitude. When the Polar Vortex becomes weak and wobbly, it is possible for large areas of polar air to be displaced southward, often resulting in extremely variable conditions throughout the mid-latitudes. Some areas will be unusually warm while other areas experience extreme cold.
This week, however, the Polar Vortex is actually quite strong. The air over our region this week has come from the Arctic, not the North Pole. It will be a cold week, but it is not a "Polar Vortex."