Severe Cold Weather

Frigid, and in some cases record-setting, cold air stretched from Minnesota to Georgia on Monday, while another winter storm began to dump snow across the mid-Atlantic before turning up the coast toward a winter-battered Boston.
Mr. Darnley said the cold temperatures across much of the eastern U.S. have their origin in a low-pressure system over the Bering Sea between Alaska and Russia. That system has created a blocking pattern along the coast of California, allowing arctic air to sweep down into the eastern part of the country.
The same weather pattern has also helped set the conditions for warm moisture to mix with cold northern air, forming the winter storms that have ridden up the East Coast and socked Boston repeatedly, say meteorologists.

http://www.wsj.com/articles/bitter-cold-follows-latest-new-england-snowstorm-1424099641
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