A massive and powerful storm is expected to hit southwestern Ontario at the end of this week, bringing with it below-freezing temperatures for a week.

The Canadian Environment Agency confirmed that the weather system, moving northeast from the United States, will first head to the Great Lakes region where it will bring strong winds and heavy snow to parts of the Golden Horseshoe area late Friday night through Saturday morning.

The weak but still fast-moving low-pressure system is scheduled to hit southern Ontario on Thursday before the storm. Snow thickness is expected to reach two centimeters, and wind speeds to reach 19 km/h.

By Friday, there will be more snow with winds reaching 60 km/h in the Greater Toronto Area.

The storm is expected to continue until Saturday, accompanied by scattered gusts and wind speeds up to 59 km/h.

Bill Coulter, a meteorologist at CP24, said that snow may mix with rain showers along Lake Ontario, which may "keep accumulations at the lower end of the accumulation spectrum," and he said residents should expect 10 to 20 cm across much of the Greater Toronto Area and five to 10 cm in areas close to Lake Ontario.

By Sunday, snowfall will stop, but the day will be cloudy with sunny intervals and temperatures will drop to -6 degrees Celsius.

Coulter added: "Although there is still some uncertainty about the exact path of the system and the precipitation mix, all models agree that this storm will be a game changer in terms of temperature."

"It acts as floodgates, behind which bitterly cold air will flow into the region on Sunday and most of the following weekdays, so we will have to prepare for the coldest weather yet in this cold weather season after the early weekend snow and mix burst."