Icy Blast Begins to Ease in Midwest, Northeast US

Meteorologists linked the spell of brutal cold to the so-called polar vortex, a cap of icy air that usually swirls over the North Pole. Changing air currents caused it to slip down through Canada and into the U.S. Midwest this week.

from Top World News- News18.com http://bit.ly/2GgQlSl