High Impact Winter Storm Takes Aim at Ontario

A Colorado Low storm system will move out of the American Upper Midwest on Friday and threaten to bring a large winter storm to the Great Lakes region this weekend. The persistent colder than normal air currently over Ontario combined with the moisture and energy from this storm is likely to bring high impact weather to the eastern half of the province. Some of the risks from this storm are heavy snow over 25cm for Northeastern Ontario, significant freezing rain to regions north of the #401 corridor and heavy rain in southwestern Ontario.

The leading edge of an approaching winter storm arrives in the province on Friday to bring snow to regions north of Lake Huron and rain for southern Ontario.

Early Saturday morning the risk of freezing rain starts for locations south of the Algonquin Park region and north of the Greater Toronto Area. This area of freezing rain is likely to slide south into all of southern Ontario late Saturday into Sunday morning to bring significant icing. The freezing rain could continue for all of Sunday before moving out and leaving behind 25mm+ of ice accumulation. If that much ice does accumulate then all infrastructure from roads to the power grid could be significantly impacted.

While this freezing rain event is happening across many of the province’s cities, there is the also the potential for heavy rain in extreme SW Ontario where up to 50mm is possible to elevate the risk of flooding.

Areas to the north of the swath of freezing rain are likely to be a band of heavy snow. 25-40cm of new snowfall is possible along a line from Sault Ste. Marie to Sudbury to North Bay. The most substantial snow is likely to arrive on Sunday into Monday.

The storm is still several days away, and the exact path and intensity could still change as the event approaches. Stay tuned to local forecasts and watch for weather warnings later this week as the likelihood of a high impact weather event remains high through the weekend.