Washington - A light dusting of snow that stuck drivers in icy gridlock for hours in and around Washington served as an ominous prelude to the massive blizzard bearing down Thursday on the eastern United States.
Less than an 2.5cm of snow fell on Wednesday night in the capital area, but that was enough for roads to immediately freeze over. Hundreds of accidents left drivers stuck for hours in icy gridlock after efforts to lay salt ahead of the dusting proved ineffective.
Washington Mayor Muriel Bowser apologised for the city's "inadequate response.
"We are very sorry for [our] inadequate response," said Bowser, who declared a 15-day state of emergency ahead of the potentially historic blizzard. "We should have been out earlier, with more resources."
For people already scrambling to prepare for up to 0.6m of heavy wet snow, the trouble caused by a mere dusting provided more reason to worry about what the National Weather Service is calling a "potentially crippling winter storm" expected to blanket the Mid-Atlantic region starting Friday afternoon and continuing through Sunday.
Most major school districts in the region either closed on Thursday or opened late. Bowser announced that the city's schools would pre-emptively close on Friday, and that city offices would close at noon, hours ahead of the storm. A decision on federal workers was pending on Thursday.
Smaller amounts of snow are expected for New York, Boston and other northern cities, but forecasters warned of high winds, power outages and coastal flooding up and down the east coast.
States of emergency were declared in Virginia, Maryland and Pennsylvania, where road crews were out in force on Thursday. Blizzard watches were in effect from Virginia through New Jersey and beyond.
All major airlines have issued waivers for travel over the weekend, allowing passengers to rebook onto earlier or later flights to avoid the storms. The airports included vary by airline but include some cities in Kentucky, Tennessee and West Virginia all the way up the coast to New Hampshire and Massachusetts.
One major event in Washington was still on: the March for Life, an annual anti-abortion rally that's usually one of the largest events in the capital. It will be held on Friday, the anniversary of landmark 1973 Supreme Court ruling legalising abortion.
And it took an act of Congress, but the children of Washington will finally be able to sled down Capitol Hill, the US Capitol Police announced on Thursday. The powerful House Appropriations Committee, whose chairman's office overlooks a prime sledding spot, made sure of that, instructing officers to "forbear enforcement" when sledders are on the grounds.