A snowplow clears the road outside Citadel High School in Halifax. (Mari Ito/CBC)

Emergency crews are preparing for dangerous winter weather conditions after Environment Canada issued snowfall, wind and storm surge warnings for much of the region.

Up to 50 centimetres of snow is expected in parts of New Brunswick and as much as 30 centimetres is forecast for parts of Nova Scotia.

Wind gusts of up to 100 km/h are expected to whip up whiteouts in all three provinces, with the west side of the Cape Breton Highlands expected to see the worst of it with gusts reaching 160 km/h.

"People are going to be quite surprised by how strong these winds will actually be," said CBC Meteorologist Trevor Adams.

RCMP are urging motorists to drive carefully and monitor the weather throughout the day.

In P.E.I., the Confederation Bridge has issued a travel advisory that high winds may result in traffic restrictions between P.E.I. and New Brunswick starting about 7 p.m. until about 7 a.m. Sunday.

The combination of high astronomical tides, storm surge and large pounding waves could also result in coastal flooding and could damage infrastructure along the Atlantic shoreline and Northumberland strait during high tide Saturday night, Environment Canada warns.

Flight cancellations, power outages expected

Air Canada is advising travellers to expect delays and cancellations of flights travelling to and from the Maritimes throughout Saturday and into Sunday morning. Customers should check the status of flights before heading to the airport.

In New Brunswick, flights were disrupted at the Moncton airport Saturday afternoon. An Air Canada flight to Montreal was cancelled and two other flights — one en route to Toronto and one to Montreal — were delayed. The airport tower was also put on standby to accept any flights diverted from Halifax.

At both the Saint John and Fredericton airports, flights departing to and arriving from Toronto and Montreal were either delayed or cancelled Saturday afternoon, but evening departures and arrivals in Saint John were expected to remain on schedule.

In addition, heavy snowfall may also result in "contaminated runway conditions, which could restrict the amount of baggage aircraft may accommodate," Air Canada said in a news release.

"In the event certain flights experience such limitations, Air Canada and Jazz will work to expedite baggage delivery for affected customers on the first available flights following the end of the weather event," the company says.

Snow plows, hydro workers, hospitals on alert

In Halifax, extra snow removal crews have been called in to help keep the runways clear at Stanfield International Airport.

"By the looks of the forecast, they'll be working around the clock," said Ashley Barnes, spokeswoman for the airport authority.

City snow removal crews are also out in full force, working 12-hour shifts, said spokesman Gordon Hayward.

"We'll keep going that way indefinitely until we get everything cleaned up," he said.

Halifax Metro Transit will stay on the road, but delays can be expected, said spokeswoman Lori Patterson.

"The good news is it's on a weekend when not as many people are using public transit, trying to get back and forth to work," she said.

If public transit is ordered off the road, a plan is in place to make sure emergency health care workers can get to the hospital. A special crew will be sent out in four-wheel-drive vehicles to collect essential staff, said Maureen Wheller of the Capital District Health Authority.

Ferries affected

Weather conditions are also causing ferry problems. Maritime Atlantic officials say the crossing between Nova Scotia and Newfoundland has been affected.

The Atlantic Vision ferry from Port au Basques, N.L., was forced to heave to offshore after being unable to dock at North Sydney Harbour due to high winds.

In New Brunswick, some ferry services are being shut down. The John E. Rigby's last run between Deer Island and L'Etete will be at 4:30 p.m., while the Princess II will stop after its 5 p.m. crossing, officials said.

Meanwhile, power utilities in the Maritimes are bracing for the storm conditions.

"What we're concerned about with this storm is the potential for the very, very high winds — and with those high winds if we have wet snow, that could be something that could impact lines, with trees coming uprooted and coming down on our lines, so that's our concern," said Heather MacLean of NB Power.

"If the winds do come up to be as high as some of the predictions are, we'll be watching that very carefully."

As of mid-afternoon, more than 4,000 customers in the Dartmouth area were without power, but by 4:30 p.m., power had been restored to all but about 650.

Extra crews and contractors are on standby across the region because it's unclear which province will be hit the hardest, said Stacey Pineau of Nova Scotia Power.

"When we are waiting on a storm like this, we'll wait and see which part of Atlantic Canada gets worst hit. We'll share crews as appropriate," she said.