Around 420,000 customers were without power up and down the Eastern Seaboard and in Ohio as severe thunderstorms moved through the region.
A survey of outages maps for electric utilities from South Carolina up to Maine indicated that thousands of homes and businesses were without power just before midnight Thursday. The Carolinas, Maryland, Pennsylvania, New York and Ohio recorded a particularly high number of outages.
Shortly after midnight, a tornado warning was issued for parts of New Jersey, not far from the Pennsylvania border. A National Weather Service statement advising people to take cover immediately said "a severe thunderstorm capable of producing a tornado" was located just north of Trenton, moving northeast at 55 mph (90 kph), with radar indicating rotation.
The weather service said storms carrying damaging winds and torrential rainfall would continue to push north overnight, possibly downing trees and causing flooding.