Despite intense snowfall in Ottawa overnight Saturday, Environment Canada says the heaviest snowfall is expected throughout Sunday afternoon.

The city remains under a winter storm warning, with 15 to 25 centimetres of snow expected to accumulate throughout the day and another 5 centimetres expected to accumulate Sunday night, Environment Canada said in an updated warning.

As of 4:30 p.m. Sunday, snow was 34 centimetres deep at the Ottawa airport and 29 centimetres deep at the Gatineau airport.

Rapidly accumulating snow could create hazardous travel conditions, with visibility reduced to near zero at times due to heavy and blowing snow.

The storm is expected to bring wind speeds up to 60 kilometres per hour. Environment Canada is urging residents to delay non-essential travel until conditions improve.

Snow crews battle storm

Bryden Denyes, area manager of special operations with the city, said plows have been out since the storm began, focusing on major roads first. He says intense winds blowing snow are making the cleanup that much more difficult, particularly in rural areas.

“This will be a scenario where when we plow a road or a sidewalk very soon after, it may not look like we plowed anything. That’s just because of how fast the snow is coming down in the wind, and then because of the accumulation totals for this storm being quite high,” Denyes said.

Since the storm hit, Ottawa’s emergency services have been responding to collisions.

An Ontario Provincial Police spokesperson told CBC that officers had responded to 37 collisions on OPP-monitored roads in Ottawa since 6 a.m. Sunday, though no injuries were reported.

The Ottawa Police Service said it had responded to 19 collisions since 8 p.m. Saturday.

Transports et Mobilité durable Québec spokesperson Martin Girard said no provincial roads are currently closed, but the province will not hesitate to close a road if necessary.

Reports of snow covering furnace vents

Ottawa Fire Services took to X late Sunday afternoon to remind residents to check their carbon monoxide alarms.

The service said it has responded to several calls for carbon monoxide inside the home after snow covered hot water and furnace vents, keeping the odourless and deadly gas inside.

Airport and transit disruptions

Crews at the Ottawa Macdonald-Cartier International Airport are “out in full force dealing with the snow and keeping the runways clear and safe,” according to an emailed statement from an airport spokesperson.

FlightAware reported 36 delayed flights at the airport and 53 cancellations Sunday afternoon.

OC Transpo is running its regular Sunday service, but delays are expected due to the storm’s impact on the roads, the transit agency said in a memo to city council. 

“Buses are operating as intended, but like everyone on the road, delays are expected due to poor weather conditions. The Severe Storm Schedule for buses will not be implemented as it is only used on weekdays,” the memo reads.

The city’s on-street parking ban, effective from 10 a.m. Sunday, will remain in place until further notice.

The city began plowing residential streets at 10 a.m. Sunday but expects multiple passes will be needed due to the fast accumulation, Denyes said.

“We’ll just keep cycling through the storm in our response until it ends,” he said. “And then we’re going to get into our cleanup of the storm, which will include moving into snow removal operations.”