A powerful low pressure system will impact most of Ontario and Quebec beginning on Thursday and lasting until Christmas Eve.
The low will bring snow, mixed precipitation, rain, and exceptionally strong winds.
For areas northeast of Lake Superior and northeastern Ontario south to North Bay mostly snow is expected. Heavy snow and strong winds are expected. These areas could see snowfall amounts of 20 to 40 cm. Wind gusts could reach 100 km/h.
Across Southern Ontario, rain is expected on Thursday and Friday. On Friday night rain will change to snow as temperatures fall drastically. Areas east of Lake Huron and Georgian Bay could see heavy snow with amounts potentially exceeding 20 cm. Eastern areas of Southern Ontario could see 5 to 15 cm of snow. 10 to 20 mm of rain is expected across western areas of southern Ontario Across eastern sections of Southern Ontario rainfall amounts will range from 20 mm to as much as 100 mm. Wind gusts are likely to reach 100 km/h.
Across southern Quebec significant snow, strong winds and blowing snow are expected over areas north of the St Lawrence River, while over the areas to the south, some of the precipitation will fall as rain. Freezing rain is likely in the snow-to-rain transition area. Rainfall amounts of 10 to 20 mm is expected, except for the Montreal region where significantly higher amounts are expected, 30 to 60 mm could occur in that area. Snowfall amounts of 20 to 60 mm is expected for areas north of the St. Lawrence River. Wind gusts between 50 and 90 km/h are expected.