Arctic Blast To Bring Intense Snow Squalls to Southern Ontario’s Snowbelts With Up to 50cm of Snow Possible by Saturday

We already got a rude awakening earlier this week with much colder temperatures and some lake effect snow through the snowbelts. That was only the beginning though as another wave of cold Arctic air is expected to push into our region during the day on Friday setting the stage for some strong snow squalls to develop off Lake Huron and Georgian Bay. The lake effect activity will actually begin during the late afternoon on Thursday into the evening hours with a westerly wind pushing heavy snow into the Southern Muskoka and Haliburton area.

This intense squall will deliver a few hours of rapid snowfall accumulation to regions like Port Carling, Bracebridge, Gravenhurst and Minden. Some areas will easily pick up the forecasted 10-20cm within the evening and early overnight hours of Thursday. The blast of cold air will invade the province early Friday morning resulting in a change in the wind direction and shifting the powerful squalls off Georgian Bay southward with an additional band developing off Lake Huron affecting parts of Huron, Perth, Grey and Bruce counties.

Snow squalls off Lake Huron and Georgian Bay will continue throughout the day on Friday with a particularly strong band somewhere between Kincardine and Saugeen Shores. The squall activity off Georgian Bay will be focused on the southeastern shoreline including Collingwood, Angus, Wasaga Beach and Barrie. Although the latest data seems to indicate it won’t be as organized as the squalls off Lake Huron so the snowfall rates will be lower.

Overnight Friday into Saturday morning we’ll see another change in the wind direction to a more northwesterly flow. This will cause the organized band near Kincardine to sink southward and bring heavy snow to areas just to the north of London. It may continue into the afternoon on Saturday before fading out as conditions become unfavourable for lake effect snow.

As far as accumulation, keep in mind that nailing down the exact location of these squalls is tricky and the accumulation will vary significantly depending on where they set up. With that being said, we believe there is a zone that includes Kincardine, Hanover, Mildmay and Minto that has the potential to see as much as 30-50cm of accumulation by the end of day Saturday. Localized amounts may even exceed 50cm should the squall lock into a particular location for an extended period of time. For other regions to the east of Lake Huron, we expect the general 15-30cm of accumulation over the next two days although not everyone will see that.

The lake effect activity off Georgian Bay will first focus on the Muskoka region late Thursday into Friday morning with between 10-20cm of accumulation possible by sunrise Friday. After the squall sinks southward it will bring a few hours of heavy snow to Northern Simcoe County before settling in around the Barrie/Collingwood area. Accumulation for Northern Simcoe County will be around 5-10cm while further south the total accumulation will be closer to 20-30cm. These squalls may stretch into parts of York Region and the Kawartha Lakes especially near Lake Simcoe which could see localized totals between 10-15cm.

We have only shown the affected regions on our map. The rest of Southern Ontario including Eastern Ontario and Extreme Southwestern Ontario will see a few flurries over the next few days with little to no accumulation.