ALBANY (AP) — Hundreds of school districts from Buffalo to New York City have cancelled classes and authorities are advising people to stay off the roads as a nor’easter starts to pummel the Northeast.

Gov. Andrew Cuomo has declared a state of emergency Tuesday for all of New York’s 62 counties, including New York City’s five boroughs. The Democrat also directed non-essential state employees to stay home from work — except in Franklin, Essex, Jefferson, St. Lawrence, Lewis and Clinton counties.

The National Weather Service says the storm will drop more than a foot of snow across much of the upstate region, with some areas getting up to 18 inches and higher elevations in the lower Hudson Valley expected to get 2 feet or more.

Blizzard warnings have been issued for much of the region south of Albany, where high winds could produce whiteout conditions.