Mercury plunges after artic chills sweep America
News
An Arctic front plunged into the Washington region of USA, bringing very cold temperatures
Important facts
Cause:
A swirl of arctic air broke away from the polar vortex that usually encircles the North Pole and moved south towards America
Polar Vortex:
- The polar vortex is a large area of low pressure and cold air surrounding both of the Earth’s poles. It always exists near the poles, but weakens in summer and strengthens in winter.
- The term “vortex” refers to the counter-clockwise flow of air that helps keep the colder air near the Poles.
- Often during winter in the Northern Hemisphere, the polar vortex will become less stable and expand, sending cold Arctic air southward over the United States
