A nor'easter bearing down on Nova Scotia is causing traffic delays on the ground and in the air.

More than 20 collisions were reported to the police within an hour on Friday afternoon, said Cpl. Andrew Joyce, a spokesperson for the RCMP.

"It's not a good time to be out on the roadways," he told CBC Radio's Mainstreet at 5:15 p.m. AT. "To my knowledge, as of yet, there have been no serious injuries reported."

Joyce said the collisions were "all over the province" and warned drivers should stay off the roads unless it's an emergency.

"It's risky," he said.

Cape Breton Regional Police officers had responded to 13 accidents as of 5:45 p.m. AT. There were no serious injuries, said Staff Sgt. Paul Muise.

Flights delayed, cancelled

Meanwhile, the Halifax Stanfield International Airport's arrivals and departures boards showed dozens of cancellations and delays on Friday afternoon.

"We're seeing significant impacts today and into this evening," said Ashley Gallant, a spokeswoman for the airport.

Gallant said the cancellations are widespread. Many airlines are looking ahead and making adjustments to future flight schedules, she said.

"Travellers can expect flight schedule changes tomorrow as well, even when this storm passes. Then, airlines will sort of be in recovery mode tomorrow," Gallant said.

The airport is advising anyone with travel plans to check ahead.

Antigonish hit hard

Thousands of power customers without electricty in the Antigonish area, according to Nova Scotia Power, as heavy snow continues to fall.

Ryan Kaiser, who lives in Lakevale, said power lines were hanging under the weight of the snow, some of the downed entirely. Cars were stuck on hills and trees snapped or bent over, he said. 

"This is likely the worst storm I've seen in recent years," Kaiser said. "It's the first time I could not make it safely to work in seven years. It was impossible to know where you were on the road — or if you were going to smash into a stuck car."

By 8 p.m., 30 cm of snow had fallen, he said. Highway 337 was impassable, the plow unable to keep up. 

"It'll be interesting to see what the morning brings," Kaiser said.