The polar vortex is making winter interesting again in 2019, five years after it first made headlines. As fellow Forbes contributor and meteorologist Marshall Shepherd recently pointed out, the polar vortex isn't new. It's a mass of low pressure and cold air over the winter pole that sometimes shifts a little further south. (A lobe of) "The Polar Vortex"... coming to a theater near you. Thoughts on #cold outbreak next week: - Could be coldest lows we've seen in some Midwest cities in 2 to 5 years.

Source: Forbes January 24, 2019 19:18 UTC