The snow and ice pellets expected Saturday night in Eastern Ontario will change to freezing rain by Sunday morning, Environment Canada reports.
The National Weather Service used an Ice Storm Waring for Erie, Niagara, Orleans, Genesee, Monroe, Wyoming and Livingston counties from 2 p.m. Saturday through 2 p.m. Sunday.
Ice build-ups of this magnitude combined with gusty northeast winds up to 60 kilometres per hour could result in widespread power outages because of fallen tree limbs and power lines.
Provincial Police Sgt. Kerry Schmidt said there had been more than 200 collisions on the highways in the Greater Toronto Area by Saturday afternoon.
A powerful low will move across the Great Lakes, whipping up strong winds and heavy rain for most of southern lower MI through the day Saturday.
An ice storm sweeping through southern Ontario could down power lines, delay flights and lead to risky driving conditions.
A freezing rain warning is in place for Peterborough and southern Peterborough County, Lindsay and southern Kawartha Lakes, and Northumberland County, with an ice storm forecast for Sunday.
The NWS says there could be significant icing with about a half inch of ice possible.
Periods of freezing rain may continue into Monday with a high temperature of just a few degrees above freezing.
By Sunday, parts of the region could be grappling with up to 25 millimetres of frozen ice accumulation.
"It's a lot of freezing rain, no question about it", said Kimbell.
Hydro One says it has crews ready to respond to outages 24/7, and additional resources are on standby this weekend. According to CTV News, by early afternoon around 8000 people were left without power.