Winter storm arrives in Ottawa with snow changing to freezing rain overnight

A winter storm battering Ottawa with snow will shift to freezing rain overnight before temperatures rise above the freezing mark Wednesday.

Flakes started falling in downtown Ottawa just after 1 p.m. Tuesday, reducing visibility at times through the afternoon. 

Environment Canada has issued a winter storm warning for Ottawa, Prescott-Russell, Smiths Falls, Perth, eastern Lanark County, Barry's Bay, Killaloe, Petawawa, Pembroke, Renfrew, Arnprior and Calabogie.

A snowfall warning has been issued for Westport, western Lanark County and the Tweed-South Frontenac area.

The weather agency is predicting 10 to 20 cm of snow in Ottawa, but parts of the Ottawa Valley could see 15 to 30 cm. 

• OC Transpo’s plan to keep service running in the storm

A warning was also issued for parts of western and central Quebec, where the storm could bring between 20 to 40 cm in the Outaouais region and the lower Laurentides.

"Snow associated with a major winter storm is expected to arrive this afternoon and continue into Wednesday morning. Snow will likely change to ice pellets or freezing rain tonight. Several hours of freezing rain are possible, particularly in the Ottawa Valley.," the weather agency said.

"The amount of snow will depend on how quickly precipitation changes to ice pellets or freezing rain, although some locations may receive 10 to 20 cm of snow."

Heavy winds could also begin overnight, with easterly winds at 30 km/h gusting to 50 km/h.

Senior climatologist David Phillips told CTV News on Tuesday that snow will fall for approximately nine hours then freezing rain and ice pellets will come in for about five hours late this evening.

"This one has got some force behind it – it's just going to drive right through, bringing a complex mix of rain and snow and freezing rain, ice pellets – a real congealed mixture of everything above," he said.

Phillips says it is difficult to predict the amount of freezing rain or snow expected because temperatures will hover around the freezing mark all night.

"All that interaction around that 'sweet zone' makes it a real challenge to get the amount of precipitation and the type of precipitation right," he said.

Environment Canada says rapidly accumulating snow could make travel difficult in some locations and poor weather conditions may contribute to transportation delays.

"Take extra care when walking or driving in affected areas," Environment Canada said.

Some school boards across eastern Ontario and the Ottawa Valley have already cancelled school buses ahead of the storm.

OC Transpo says to anticipate delays and to plan ahead to allow extra time for travelling. 

Hydro Ottawa says the storm has the potential to cause power outages and tree damage. Crews will remain on stand-by as they monitor the weather conditions.

"Customers are encouraged to be prepared in case of extended power outages. Please ensure that electronics, such as cell phones and laptops, are fully charged ahead of the storm," Hydro Ottawa said in an email to residents on Tuesday.

Residents can visit the Outage Map for information on power outages.

The City of Ottawa has issued a daytime parking ban, which will be in effect beginning Wednesday (Jan. 10) between 10 a.m. and 7 p.m.

• Daytime parking ban issued for Ottawa on Wednesday

During a winter weather parking ban, parking is prohibited on city streets so crews can plow easily and effectively. 

Winter night parking regulations are now in effect in Gatineau until the end of March to free up the streets for snow clearing. On-street parking will be not be allowed between midnight and 6 a.m. Sunday through Friday, and from 3 a.m. to 6 a.m. on weekend.

Ottawa Police is reminding drivers to be prepared for changing road conditions and to adjust their driving accordingly.