Virginia, Maryland, North Carolina, Pennsylvania and Columbia declare state of emergency, with forecasters warning of two feet of snow in Washington and storm surges to rival Hurricane Sandy
Swathes of the east coast of the United States are bracing themselves for a huge storm, forecast to sweep in the early hours of Saturday and blanket the region with snow.
Winter Storm Jonas was predicted to affect one in four Americans. On cable news, forecasters were warning of "a significant risk of loss of life and property." Tom Singer, CNN's forecaster, said storm surges could rival those of Hurricane Sandy.
As of early Thursday afternoon, more than 76 million people were covered by either a blizzard watch, blizzard warning, winter storm watch, winter storm warning, winter weather advisory, or freezing rain advisory from Kansas to the Carolinas to the New York City area.
Washington DC, New York, Philadelphia and other eastern cities readied fleets of snow ploughs, airlines cancelled flights and residents stocked up on supplies in the face of a predicted two and a half feet (76cm) of snow.
Baltimore and Washington were expected to be the worst hit cities, with 50mph winds and two feet of snow.
At least five states had declared emergencies by Thursday afternoon, ahead of the season's first major Atlantic Coast storm started to move over the Mid-South before barrelling on an expected north and eastward course.
Governors in Virginia, Maryland, North Carolina and Pennsylvania joined Columbia in declaring states of emergency, and the governor of West Virginia declared a state of preparedness.
Trains in the Washington area including the second busiest US subway system would be suspend operations from late on Friday until Sunday.
People were being warned to only travel if absolutely necessary, and supermarket shelves were being stripped of bread, milk and other essentials as millions of residents in the storm's path prepared to hunker down for a wintry weekend. Consumer watchdogs warned against illegal price gouging for such essentials as generators, batteries, torches and hotel lodging.