A blizzard hitting the north-eastern United States is already causing major disruption.
Massachusetts, Rhode Island, New York, Connecticut and Maine are all on an emergency footing, with millions of residents being warned to stay indoors.
Massachusetts Governor Deval Patrick has temporarily banned all non-emergency traffic and he's warning people to prepare for the worst possible conditions.
The BBC reports that airlines cancelled more than 4300 flights - including all those to and from the three major airports in New York City - and the train operator Amtrak has suspended nearly all services north of the city.
People have been warned to stay off the roads, and stock up on food and other supplies as the storm affects 25 million people in the region.
With the heaviest snow expected late on Friday and early on Saturday, blizzard warnings were in effect for much of the coastal section of the north-eastern US, from Newark to southern Maine.
Forecasters said the storm could dump as much as 90cm of snow in some places as it hammered swathes of territory, with winds of up to 120km/h expected to create deep drifts.
Parts of Massachusetts were already under a foot of snow by Friday night, with more expected over the weekend. Some 350,000 homes and businesses across the region were without electricity.