Polar vortex

The polar vortex is a large area of low pressure and cold air surrounding the Earth’s poles. The term vortex is used to describe the counter-clockwise flow of air that helps keep the colder air near the Poles. Many times, the polar vortex expands during winter at the northern hemisphere, leading to cold air flowing southwards. While it remained bottled up around the North Pole for the past two years, it is now threatening to sweep across North America, Europe and Asia from late January 2021.