Washington Post: For days, it`s appeared on computer model maps in the form of deep blue and purple shades. Now it`s about to get real and up close and personal. Some of the coldest air in years, if not decades, is poised to pour into the U.S., with mind-boggling low temperatures.
Basically a large whirlpool in the atmosphere originating at the north pole -- in geek speak known as the polar vortex -- is diving into the Lower 48.
The polar vortex (as simulated by the circulation at 500 mb in the GFS model) dives...