Flash freeze could make roads 'treacherous' on Friday, says Environment Canada

A rapid drop in temperature forecast for Friday could turn wet, rainy roads into sheets of ice, Environment Canada says.

 A winter storm is expected to hit the Ottawa region Thursday night and could continue through the holiday weekend, according to a special weather statement from Environment Canada.

Peter Kimbell, a warning preparedness meteorologist with Environment Canada, said snow will begin Thursday and then turn to rain which is expected to continue Friday when temperatures could reach a high of 9 C. 

Later on Friday, a powerful cold front moves in which will cause temperatures to fall to around –5 C within one to three hours, he said.

"When it freezes that rapidly, roads become very hazardous — treacherous — so rapidly, it's extremely dangerous," said Kimbell on Tuesday.

The falling temperatures will come with strong, potentially damaging winds and snow that may be heavy at times.

Drivers should plan around the weather conditions on Friday, said Kimbell, who added the freeze could start as early as afternoon rush hour.

"In any case, Friday late in the day, is really a time people would want to be off the roads because it has a potential to cause a lot of problems for motorists," he said

Areas downwind of Lake Huron and Georgian Bay could see blizzard conditions late Friday, according to the weather agency. Snow is expected to last multiple days through the weekend for areas east of the Great Lakes.

Holiday plans may be affected

Environment Canada is encouraging people to change travel plans for the holidays and warns outages are possible.

"While there is high confidence in a high impact winter storm, the details regarding wind speeds, precipitation types and amounts remain highly uncertain at this time," Environment Canada said.

"Please monitor your local forecast and the latest alerts for your area."