Bitter cold in US Midwest: What is the polar vortex and why is it so cold?

January 30, 2019 7:19 AM

CHICAGO (REUTERS) - Meteorologists have blamed a phenomenon called the polar vortex for the bitter cold that has descended on much of the central and eastern United States this week, forcing residents to huddle indoors, closing schools and businesses and cancelling flights.

from
The Straits Times World News