A nasty winter storm struck the Maritimes early Monday, dumping more than 20 centimetres of snow in some areas, closing schools and cancelling flights.

"You have to anticipate the unknown," Const. Chantal Farrah told CTV Atlantic. "So when you're on a main street in your community, you don't know if you're going to have a car, or a snowplow, or kids sliding in their driveway."

Along with heavy snow, the low-pressure system also brought freezing rain and high winds. It moved northeastward, passing over Nova Scotia and New Brunswick,  reported.

"There is also the potential for freezing rain. Strong northeast winds will develop giving reduced visibilities in blowing snow in open areas. Total snowfall amounts will range from 15 to 25 centimetres," the weather office's website reports.

Snowfall warnings have been issued for Moncton and southeastern parts of the province, along with Kent County, St. Stephen, Grand Manan, Saint John, Sussex, Kennebecasis Valley and Kings County.

All schools in , which includes the Moncton area, were closed at noon.

Road crews expected to work 12-hour shifts to keep the roads clear.

"We'll be working until midnight," said Robert Melanson, who operates a snow plow in Moncton. "If another crew is needed after that, they'll get a skeleton crew."

In Nova Scotia, Environment Canada issued warnings for much of the province. Annapolis County, Cumberland County, Hants County Kings County and surrounding areas were under a freezing rain warning while Halifax, Guysborough and Antigonish are under wind warnings.

All schools within the  were closed Monday. Parts of southwestern Nova Scotia were expecting between five and 15 centimetres of snow.

In Prince Edward Island, the western part of the island continues to be under a snowfall warning, Meanwhile in the east; residents had to contend with hazardous driving conditions as freezing rain is expected to hit the area.

All schools have been closed for the day on the island.

Air Canada is warning that travel in and out of Halifax and New Brunswick airports may be adversely affected due to the storm.

With a report by CTV Atlantic's Kelland Sundahl