The storm is expected to be a long, drawn-out affair, dropping heavy rain on some parts of New England as late as Thursday night, the National Weather Service said.
And its effects were already being felt as it approached the Atlantic coast: State Highway 12, the only road connecting Hatteras Island to the North Carolina mainland, was closed for a few hours Monday morning because a combination of high tide and strong onshore winds from the outer edges of the storm flooded it, the state Transportation Department said.
More from NBC:
Wal-Mart changes 'I can't breathe' ad after complaints
Subway dig unearths ancient farm in heart of modern Rome
Coffee in a New York minute
The storm is expected to bring powerful sustained winds and gusts of up to 60 mph, especially during the worst of the wet weather Tuesday afternoon. The rain is forecast to change over to snow overnight into Wednesday, with the heaviest snow in the interior Northeast from northern Pennsylvania to northern Maine.
Six inches of snow could fall in some places, and as much as 2 feet in higher elevations. Flight delays are probable in Northeast hubs on Tuesday and Wednesday, according to The Weather Channel.