Here's when Ottawa could receive up to 25 cm of snow

The first significant snowstorm of 2023 arrived in Ottawa Thursday afternoon, threatening to blanket the capital with up to 25 cm of snow.

Environment Canada has issued a winter storm warning for Ottawa, while the city of Ottawa has issued a daytime parking ban from 10 a.m. to 7 p.m. on Friday.

"The good news is that I think we've downgraded the snow amounts just a bit – we called for 20 to 30 (cm), now it looks like 15 to 25," Environment Canada senior meteorologist David Phillips told CTV News at Noon.

"I think the reason for that is that it is not just going to be a pure snow event. We see perhaps in the wee hours towards midnight, we see the possibility of rain included and so that will rob some of that snow from falling. It's primarily a snow event."

Environment Canada's winter storm warning calls for snow, heavy at times, beginning this evening and tapering to light snow by late Friday afternoon. The warning calls for 15 to 25 cm of snow for the Ottawa area, but the weather agency warns some areas could see 30 cm.

"About 10 o'clock tonight, as the system draws in cold air from the north it will be primarily a snow event – heavy snow. The most snow will be overnight," Phillips said.

Environment Canada is recommending people consider postponing non-essential travel during the storm.

The forecast calls for 10 cm of snow thursday night, with another 10 to 15 cm of snow on Friday.

The winter storm warning is in effect for Ottawa, Prescott and Russell, Plevna-Sharbot Lake-Western Lanark County and Smiths Falls-Perth-Eastern Lanark County.

Environment Canada says those areas could see 20 to 25 cm of snow.

There is a snowfall warning in effect for the Ottawa Valley, including Pembroke, Petawawa and Cobden.

Environment Canada says all areas could see up to 20 cm of snow Thursday night and into Friday.

Parking ban

The city of Ottawa has issued a daytime winter weather parking ban for Friday to allow crews to plow streets "easily and effectively."

The winter parking ban will be in effect from 10 a.m. to 7 p.m.

Only vehicles with on-street parking permits can park on city streets during the winter weather parking ban.

Six park and rides will be open for parking during the winter weather parking ban. The locations are:

• Riverview (at Earl Armstrong)
• Innovation (at Innovation Drive)
• Chapel Hill
• Nepean Woods (at Strandherd Drive)
• Greenboro
• Leitrim

Vehicles may also park at the following locations during the winter weather parking ban:

• Kanata Recreation Centre – 100 Charlie Rogers Place
• Minto Recreation Centre – 3500 Cambrian Road
• Ray Friel Recreation Centre – 1585 Tenth Line Road
• Tom Brown Arena – 141 Bayview Station Road
• Strathcona Park – 25 Range Road
• Jules Morin Park – 400 Clarence Street East
• Centrepointe Park – 260 Centrepointe Drive

All available resources deployed, city says

The city of Ottawa says all "available resources" have been deployed to clear roads, sidewalks and the winter cycling network ahead of the storm.

"Because of the duration and intensity of this storm, operations will take longer than usual to complete," the city said on its website.

The focus will be on clearing priority roads, sidewalks and the winter cycling network.

"Given the amount of precipitation expected, some residents may find it challenging to get out of their communities. We anticipate crews will transition to the residential neighbourhoods tomorrow morning," the city said.

At the start of the storm, crews will focus on Hwy. 174, the Transitway, major roads and arterials.  At 5 cm of snow, secondary roads and minor collectors will become the focus, and residential roads and lanes will be cleared once 7 cm or more falls.

"If we end up getting 30 cm, it may take us a little bit longer to clear it. But we're going to have resources out all day today, all night and just keep cycling tomorrow," city of Ottawa operations program manager Bryden Denyes said.

Heavy rain for Brockville, Kingston, Belleville

While Ottawa could see up to 25 cm of snow, an area stretching from Brockville-Prescott to Kingston, Belleville and Toronto will see heavy rain on Thursday night.

Environment Canada has issued a special weather statement for Brockville, Prescott, Gananoque, Mallorytown Kingston, Odessa, Napanee, Picton, Belleville, Quinte West and Cobourg.

The areas could see 15 to 25 mm of rain this evening, before precipitation changes to snow.

"Light showers and drizzle will give way to rain, heavy at times, late this afternoon and then change to snow by midnight," Environment Canada said.

"Note that the partially frozen ground may have a reduced ability to absorb this rainfall. A few centimetres of snow can be expected by Friday evening."