Polar vortex
The polar vortex (alternate names: Arctic cyclone or polar vortice) is a persistent large-scale cyclone located near geographical poles of a planet. On Earth, a polar vortex is usually in the middle and upper troposphere and stratosphere. The cyclone surrounds the polar highs. Polar storms lie in the wake of the polar front. They strengthen in the winter and weaken near summer. These vortexes span usually between 620 to 1,240 miles. They circulate counter-clockwise in the Northern Hemisphere.