Uccellini, who has written two textbooks on Northeastern snowstorms, said Wednesday it was too early to tell if the storm would be one for the record books. But he said it will be a rare and major storm, the type that means "you can't let your guard down."
The snow will start Friday morning, with the heaviest amounts dumped on the region that night and into Saturday as the storm moves past New England and upstate New York, the National Weather Service said.
A blizzard watch for parts of Massachusetts and Rhode Island said travel may become nearly impossible because of high winds and blowing snow.
A coastal flooding watch also is in effect for some shore communities in Massachusetts, Connecticut and Long Island.
Thanks to the ability to make their own snow, the region's larger ski resorts aren't as dependent on natural snowfall, though every bit helps.