“Rain and near record warmth will give way to a rapid freeze-up Thursday afternoon and a major snowstorm Thursday night through Friday morning,” Global News meteorologist Anthony Farnell said.
He said Ottawa can expect anywhere from 20 to 25 cm of snow overnight Thursday.
“This will combine with blowing snow to create even bigger drifts in the city,” he said.
Environment Canada has issued a special weather statement for most of southern Ontario, warning of a “messy mix of wintry weather” beginning Wednesday evening.
Farnell said 10 mm of rain will fall in Ottawa before the transition to snow.
“The temperature on Friday will remain below -10 C with a wind chill between -20 and -25,” he added.
Farnell said the storm will be a “high-impact event,” affecting residents from Windsor all the way up to Quebec City.
It should wrap up for Ottawa on Friday, but beyond that, the city could see more active weather.
Farnell said an Alberta clipper is expected early Saturday, dropping another 2 to 5 cm of snow.
“The active pattern also continues through next week with more chances of snow and potentially ice in Ottawa,” he said.
“This could end up being the stormiest period of the entire winter in Ottawa.”
It comes as the so-called “Freedom Convoy” blockade of downtown Ottawa continues Wednesday, nearly three weeks after it began.
Trucks, RVs and other vehicles with Canadian flags or banners with the word “freedom” in giant letters along their front grilles remain on Wellington Street in front of Parliament Hill, with drivers saying they will stay put until all COVID-19 vaccine mandates and restrictions are lifted.
Police issued a new warning to participants Wednesday morning, saying that they must “leave the area now,” as questions heat up about when police will act to remove the demonstrators.
— with files from Amanda Connolly and The Canadian Press