Forecasters are predicting 30 to 40 centimetres of snow today for parts of Nova Scotia and New Brunswick, and up to 30 centimetres for Prince Edward Island.
In some areas, the snow was whipped by winds of up to 100 km/h, cutting visibility to almost zero. Severe whiteout conditions are reported for Nova Scotia's Cobequid Pass, the toll highway.
High winds knocked out the power for 21,000 customers in Nova Scotia at the peak on Saturday. Most of the outages were in the western part of the province.
As of 7 p.m. Saturday, that number dipped down below 2,000.
A collision involving a snowplow hitting a power pole on Highway 7 outside Dartmouth left about 1,000 customers without electricity.
The power company says blowing snow in Shelburne County made it difficult to restore power.
"We currently have about 100 crews strategically placed across the province. However, weather conditions and travel issues are slowing down some of those efforts," said utility spokesman Aaron Veinotte.
Nova Scotia Power said it hoped to restore electricity by 11 p.m.
In New Brunswick, about 600 customers in the St. Stephen area were in the dark Saturday morning.
On Prince Edward Island, however, the lights remained on.
Most of the flights out of Halifax Stanfield International Airport were cancelled.
"We've got two crews working to keep the runways clear. But the issue is the blowing snow and the visibility. Of course visibility is a huge concern for pilots. The airlines will see what the visibility is when the time comes and that will be their deciding factor," said airport spokeswoman Ashley Gallant.
Very few cars could be seen on the roads in downtown Halifax on Saturday morning as blowing snow whipped through the streets, creating whiteout conditions.
All Marine Atlantic crossings were cancelled for Saturday.
The region's inter-provincial bus service, Maritime Bus, also cancelled all of its scheduled routes.
Most wharves on the eastern side of Cape Sable Island were under water and Route 330 was impassable as a result.
Dick Crowell, emergency measures co-ordinator in Barrington, said about a metre of water was covering the highway.
"There was a roof on one of the older homes lying in the middle of the road in Clark's Harbour. I believe that's been cleared up. There are lots of lines down. There are trees that are down and one of the fish plants has about three feet of water all around it," he said.
Parts of downtown Liverpool were also under water.
Melanie Ingersoll, owner of the town's Home Hardware, said her store wasn't damaged, but she was shocked to see water levels reaching the doorstep.
"The water is starting to go down now. So that's good news," she said.
"We're pretty much just hanging out waiting for the steps and sidewalk to clear off so we can kind of clear the ice away and we're not really open but we're here if someone has an emergency and absolutely needs to make it in."
Two storms moving in
Atlantic Canada is being pummeled by two fierce snowstorms that are combining.
One storm hit southern Ontario and Quebec on Friday, leading to at least three deaths in Ontario — two on the roads and an 80-year-old woman who was shovelling her driveway.
The other snowstorm hammered the northeastern United States, sweeping across the New York-to-Boston corridor.
The storm has dumped 47 centimetres of snow in parts of central Connecticut. More than 40 centimetres of snow is covering Mansfield, Mass., just southwest of Boston.
The U.S. National Weather Service says more than 90 centimetres of snow is expected in Boston, threatening the city's 2003 record of 70.1 centimetres.
Throughout the U.S. Northeast, 500,000 homes and businesses had lost electricity by Friday night as wet snow, freezing rain and howling winds caused havoc. By Saturday morning, that number had increased to 650,000.
Thousands of flights have been grounded. New York City's airports are closed. There's about 30 centimetres of snow east of the city.