The threat of a flash freeze in parts of southern Ontario failed to materialize Friday as there was no rapid drop in temperatures.

But the Toronto area is still being hit by blowing snow Saturday, which Environment Canada warned could make driving conditions treacherous in places. The flurries are forecast to stop by late afternoon.

"Blowing snow, poor visibility and drifting snow, not to mention slick roads, will remain an issue for drivers throughout the GTA," CBC weather specialist Jay Scotland said.

The prospect of a blast of Arctic air prompted Toronto to issue an extreme cold weather alert aimed at helping the homeless seek shelter.

Alerts are issued when temperatures are forecast to fall below -15 C.

The weather service expects a high of only -10 C on Saturday, with wind chill making it seem like -25.

The unusually seasonable weather mean motorists will share the road with vehicles they haven't seen much: snow plows and salt trucks.

"We'll be focusing initially on the expressways with salting operation," said Myles Currie, the director of transportation services for Toronto. "If we see accumulations of two to three centimeters, we'll dispatch our plows on our arterial roadways. And then we'll make our way onto the side streets…if necessary."

North of the GTA there are snow squall watches in effect for the areas around Barrie, Collingwood and the Bruce Peninsula.

Temperatures are forecast to increase to near zero degrees in the coming days, starting Sunday.

With files from CBC News