Freezing rain is expected to hit Southern Ontario on Thursday morning with the potential for an ice storm over the weekend, according to Environment Canada.

"This has the potential to be a major ice storm for some regions, with ice accumulations in excess of 20 millimetres possible," said Environment Canada in a special weather statement issued Wednesday morning.

The ice, combined with winds up to 60 km/h, could result in power outages due to fallen tree limbs and power lines, and will make travel "hazardous," the statement warns.

A fast-moving, low pressure system will arrive on Thursday, starting off as freezing rain before changing to rain as temperatures rise.

The freezing rain is expected to fall briefly around the Highway 401 corridor, but may last several hours in areas north of the city.

Areas around Lake Ontario and Highway 401 will likely remain above the freezing mark.

More freezing rain is expected for portions of Southern Ontario throughout the weekend, though it's not clear which areas will be most affected, Environment Canada said.