A fast-moving storm over-performed in some places, leaving as much as a foot of snow in parts of New Jersey, New York and Pennsylvania, forecasters said.
A new train for the busy Washington to Boston route has finally passed a computer modeling test and is set for tryouts on the tracks. Amtrak has no date yet for when it can carry passengers.
While conditions will be calmer in the Southeast U.S., more rain is expected in Maine, and more snow in parts of the West. The New York region will face brutal winds.
The cancellations were felt most acutely in Chicago, where ice and snow briefly halted all flights on Tuesday afternoon. Airports elsewhere in the Midwest and the Northeast were also affected.
Government officials and energy developers misjudged the difficulty of building huge clean energy projects in the United States, which has built very few of them.