More than 900 flights for Thursday have already been canceled as the Northeast prepares for a storm system that will unload as much as a foot of snow and have sub-zero wind chills. The weather “will lead to whiteout conditions making travel extremely dangerous. Do not travel,” said the National Weather Service. New York's Long Island will be under a blizzard warning from Thursday through Friday. Boston is supposed to get five to 11 inches of snow and temperatures as low as three degrees below zero.