Southern Ontario: Snow Squall Outlook for Thursday, January 20, 2022

Forecast Discussion

Arctic air has once again flowed into Southern Ontario which has resulted in some lake effect snow developing off Georgian Bay and Lake Huron. It appears that a fairly strong but narrow snow squall will set up off the southeastern shoreline of Lake Huron just after midnight tonight. It’s expected to continue into Thursday morning affecting locations to the northwest of London including Lambton Shore, Strathroy and Grand Bend.

There is still some uncertainty regarding exactly where this band will set up which will affect who sees the most snowfall accumulation. Current data indicates there is the potential for a small zone between Lambton Shores and Grand Bend to pick up close to 40cm by the time the lake effect snow tapers off late Thursday. Now, this doesn’t mean all areas within that zone will see anywhere near 40cm as it will be very localized. Lake effect snow will persist throughout that area into the afternoon and evening with the heaviest snow expected from the late morning to early evening on Thursday. It should come to an end by the late evening or predawn Friday.

Despite the current snow squall warning, the City of London should escape most of the lake effect snow activity. They could see a few rounds of heavy snow as the bands shift around, but accumulation should be limited to around 5-10cm. The highest accumulation will be the northwest of the city closer to the Lake Huron shoreline.

We also expect some fairly unorganized lake effect snow to develop off the southern shoreline of Georgian Bay. This could bring localized snowfall accumulation of up to 15cm to locations such as Meaford, Collingwood and Angus. Expect poor driving conditions in the affected regions tomorrow and be sure to drive according to the conditions.