TORONTO -- Torontonians are in for a cold and snowy weekend.

Environment Canada issued a special weather statement Thursday afternoon warning of “significant snowfall” in the city and most of southern Ontario.

“An approaching low pressure system will bring snowfall to Southwestern Ontario beginning overnight Friday which will spread eastward to the Golden Horseshoe on Saturday morning,” the weather agency said. “Total snowfall amounts of 10 to 15 cm are expected.”

The snow may transition to periods of rain late on Saturday, the statement said.

Winds are expected to blow up to 60 kilometers an hour in some areas.

“Visibilities will be reduced in areas of blowing snow, which can make travel hazardous,” Environment Canada warned. “Be prepared to adjust your driving with changing road conditions.

At the same time, the city issued an extreme cold weather alert, with temperatures forecast to reach -12 C overnight on Thursday without the wind chill.

Chief Medical Officer Dr. Eileen de Villa issued the alert in anticipation of colder weather conditions for the next 24 hours.

A warming centre at Metro Hall, on John Street, will be open by 7 p.m. on Thursday. It will remain open until noon on the day the alert is terminated.

The city says the most at risk of cold-related illness are people experiencing homelessness, those who work outdoors, elderly people and children.

On Friday, it is forecast to be - 6 C but it will feel like - 19 C with the wind chill in the morning.

Temperatures will warm up for the weekend, with Saturday forecast to be 2 C and Sunday 0 C.