TORONTO - A messy mix of snow, ice and freezing rain moved across southern Ontario on Wednesday, plunging the region back into the depths of winter after several days of milder weather, with Environment Canada predicting colder temperatures into the weekend. 

A winter system from the northern plains of the United States rolled in to southwest parts of the province early in the day before hitting the Greater Toronto Area. The storm was then headed for Ottawa but icy weather was predicted to linger over several regions until Thursday. 

“This one is a fairly well known storm track (that) brings a lot of moisture with it and, with those combination of temperatures, can bring a messy mix of precipitation,” Geoff Coulson, a meteorologist with Environment Canada said in a phone interview.

On Thursday, we’re expecting a second shot of precipitation possibly moving through that could give more freezing drizzle, freezing rain, ice pellets and snow to various parts of southern and eastern Ontario.”

Environment Canada said up to 20 millimetres of ice will accumulate in the southwest, such as the London and Niagara areas, by Thursday. The storm could cause extensive power outages in the region.

Up to15 centimetres of snow and ice is in the forecast for the Greater Toronto Area, and up to 20 centimetres of snow may fall in the Ottawa area, the weather agency said.

Environment Canada is warning highways, roads, walkways and parking lots across the province will become icy and hazardous so residents should take special care during the storm.