A powerful winter storm that moved into southern Ontario and parts of Quebec on Thursday, delivering a chilly mix of snow, ice pellets and freezing rain, is expected to hit Ottawa by about 4 a.m. Friday.

By 7 a.m., as the morning commute gets underway, about two to four centimetres of snow is expected to be already on the ground, according to CBC Ottawa climatologist Ian Black.

By Friday evening, that'll grow to about 15 centimetres of total mixed precipitation.

There's also a risk of freezing rain in the region with a forecast high of about 1 C and winds gusting anywhere from 30 km/h to 50 km/h, Black said.

Storm warning issued Thursday

Environment Canada issued a winter storm warning for Ottawa and eastern Ontario on Thursday morning.

Environment Canada has also issued a snowfall warning for areas of Upper Gatineau, Chelsea and the Outaouais with a "mixed bag" of between 15 and 25 cm expected to fall, mostly ice pellets and wet snow.

Most of the precipitation is expected throughout the day Friday.

Some flights scheduled for Ottawa to Toronto on Friday were already cancelled Thursday. People are advised to check the airport website before heading out to catch a flight.

Preparations underway

City crews have had to haul out all of their snow-clearing equipment ahead of the storm, a process that takes days.

Street sweepers have been out in force cleaning roads recently, so the city plans on using salt instead of dirty grit to make roads safe.

Auto repair and tire shops are reporting that some customers are cancelling scheduled plans to have their snow tires removed.

The city's annual snow budget, from Jan. 1 to Dec. 31, is $56 million per year. So far this year — ahead of Friday's storm — the city has used $48 million, or about 86 per cent.

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