Climate Central: If the cold and snow currently blanketing the Mid-Atlantic and Northeast from a fierce winter storm were not bad enough, an even colder blast is expected to arrive early next week. That's when a large section of the "polar vortex" that normally remains over Canada and the Arctic seems ready to pay an unwelcome visit to the continental U.S.
The cold air has already had a major impact. At the height of the snowstorm in Boston early Friday, temperatures were in single digits, making it one of the...