'This is one to take seriously': Officials warn of dangerous wind and coastal flooding from 'historic' nor'easter

State officials declared a state of emergency and joined Boston officials in urging residents to stay indoors during the nor’easter arriving Sunday night, calling it a historic storm.

“This is one to take seriously,” Gov. Maura Healey said Sunday afternoon, hours before the arrival of what she described as a “strong, long lasting storm.”

Healey said 12 to 18 inches are expected across much of the state, and Greater Boston is likely to see between 18 and 24 inches. Up to 75 mph winds are possible on the coast, bringing windchill temperatures in the low teens and near zero visibility.

The snow is expected to be heavy and wet and create blizzard-like conditions, and officials warned residents about power outages and downed trees. Healey and her team said anyone who loses power should contact their utility and call 211 to find the nearest warming center.

“It’s really critical for folks to stay off the roads for their safety and for the safety of those who are trying to clear the roads and clear any debris,” Healey said.

Healey activated 200 members of the Massachusetts National Guard to provide rescue response and debris removal. She directed all non-emergency state employees to work from home Monday and urged private employers to do the same.

The MBTA will be running on a sharply scaled-back schedule on Monday. Subways, trains and the commuter rail will be operating at levels similar to Sundays, and customers should anticipate longer wait times. All ferry service will be suspended Monday.

Several school districts across the state have closed, including Boston Public Schools, and several cities have enforced parking bans. A parking ban in Boston went into effect at 2 p.m. Sunday, and anyone parked on listed roads or BPS and library parking lots may be ticketed and towed.

Boston Mayor Michelle Wu encouraged everyone to stay warm, but asked people to pitch in clearing sidewalks when the storm passes.

“ Sidewalks are the responsibility of property owners, whether it's in front of your business or in front of your home, and that means clearing the sidewalk,” Wu said during a press conference Sunday morning. “ That is really important for everyone to be able to get around.”

Wu reminded residents that space savers are allowed for 48 hours after the end of the snow emergency, but are not permitted at all in the South End or Bay Village. Trash collection in Boston will be delayed by one day throughout the week.

Adrian Jordan, Boston’s chief of emergency preparedness, said during the last major storm in January, first responders responding to fires in the city encountered people out in the city on the roads due to the AFC Championship game in which the New England Patriots advanced to the Super Bowl.

“ There were a lot of civilians just out and about. We're please asking people to refrain from doing that this time around,” he said. " If nothing else comes of this — please stay off the roads. Give the plows time to work. Let the the agencies do their jobs."

Massachusetts Highway Administrator Jonathan Gulliver said he expects the state's highways should be ready for the Tuesday work commute, but he said it will take longer for secondary and local roads.

"Because of the snowfall that we have already on the ground, there is not a lot of places that this snow can be put, which means that we are in a removal operation," Gulliver said.

He said with the rate of expected snowfall, it will be impossible for plows to keep up with the snow during the height of the storm.

“ We've had a couple of really bad storms, including one a few weeks ago," Gulliver said. "If our forecast currently holds, this storm is going to make you forget about those last ones."