A powerful, fast-moving snowstorm swept into the U.S. Northeast Thursday with the potential for more than 30 centimeters of snow along the heavily populated Philadelphia to Boston corridor. Forecasters said that the storm had the potential to be the most powerful that some areas have seen in a mostly snow-free winter. Schools were closed in Boston, Massachusetts; Philadelphia, Pennsylvania; and New York City. Numerous auto accidents were reported, and more than 3,000 flights were cancelled. The National Weather Service predicted that the Boston area and eastern Maine could receive 30 to 45 centimeters of snow, and a blizzard warning has been issued for all of Long Island. New York City could get 20 to 30 centimeters and the Philadelphia area 10 to 20 centimeters. Officials also warned of high winds, coastal flooding, and possible power outages. The storm comes a day after much of the Northeast enjoyed a brief glimpse of spring, with temperatures hitting 15 degrees Celsius in some places.