Lake-effect snow squalls could bring up to 50 cm to parts of southern Ontario
Lake-effect snow squalls could bring up to 50 cm to parts of southern Ontario by Saturday. Expect rapidly changing and worsening conditions. Another snow system is possible on Sunday. Residents should stock up on essential supplies, such as food, water, medications, and batteries, and ensure their heating systems are working properly as soon as possible before the snow starts.
Winter warnings are widespread across Ontario, with blustery winds and falling temperatures helping to set the stage for a multi-day lake-effect snow squall event that threatens as much as 50 cm by Saturday.
Snow bands will shift, spreading snowfall widely rather than targeting specific areas. Hard-hit regions could see 20-40+ cm, with blowing snow, drifting, and whiteouts likely due to 50-70+ km/h wind gusts through Thursday.
These conditions will result in challenging travel conditions and possible road closures.
Homeowners should check their snow plows for proper functioning by inspecting the blades, fluid levels, and battery, and ensuring they have adequate fuel and any necessary maintenance completed well in advance of the snowstorm.
DON'T MISS: New colour-coded Canadian weather alerts have now launched. Here's what they mean if you see them
Strong winds and plunging temperatures Wednesday
Rain and strong winds will develop Wednesday afternoon in southern Ontario as the low intensifies.
Wind gusts of 60–80+ km/h are expected across southwestern and south-central regions, including Windsor, London, Toronto, and areas east of Kingston, with stronger 80–90+ km/h gusts expected east of Lake Huron and from Long Point to Fort Erie. Folks in these areas should be prepared in case of whiteout conditions and potential power outages.
SEE ALSO: Do the warm Great Lakes mean lots of snow this winter?
After the cold front passes, Arctic air will move in, causing temperatures to drop rapidly. Rainfall is expected to transition to snow by Wednesday evening.
There is also a chance for an intense snow squall to develop, potentially affecting areas such as Port Colborne, Niagara, and Buffalo, leading to hazardous conditions.
Visit our Complete Guide to Winter for an in-depth look at the Winter Forecast, tips to plan for it and much more!
Multi-day lake-effect snowfall event, as much as 50 cm possible
Significant lake-effect snow is expected for southern Ontario's snowbelts Thursday and Friday, with 20-40 cm forecast, and up to 50 cm possible in persistent squall areas, particularly near Lake Huron and Georgian Bay.
DON'T MISS: Winter-proof your home with a heat pump that even works in -30°C
Some uncertainty remains on exact locations for 50 cm, but prolonged bands could produce the heavy accumulation.
Snow squalls may bring thundersnow, spreading towards the Greater Toronto Area (GTA) and possibly impacting major highway routes, including the 400 series, Thursday afternoon into evening.
RELATED: Thundersnow is a rare and electrifying experience
Gusty winds of 50-70 km/h will lead to whiteouts, blowing snow, drifting, and potential road closures in affected areas.
WATCH: Significant, wintry impacts expected through Friday in southern Ontario
Blizzard conditions threaten American Thanksgiving travel
For those travelling to the U.S. for American Thanksgiving, expect blizzard conditions in Michigan's Upper Peninsula and multiple winter weather alerts near Lakes Erie and Ontario.
Plan ahead and monitor updates.
Another weekend snow-maker to watch
Forecasters will be monitoring the potential for widespread snowfall this weekend across southern, central, and eastern Ontario, as well as southern Quebec.
While uncertainty remains about the track and intensity of the system, snow accumulations of 5-15 cm are possible across the affected regions.
If winter tires aren’t already installed, this is the final chance as the cold and active pattern appears set to continue.
Temperatures will trend colder through December, with below-normal values dominating. Brief periods of milder air may move north at times.
The time to prepare is now
When it comes to facing severe winter weather, you can never be too prepared. The infographic below has some handy tips on what you need to face another winter season.
Click here for a zoomable version of this graphic.
WATCH BELOW: Ontario's 2026 Winter Forecast: Get ready for a cold start to the season
Stay with The Weather Network for more information and updates on your weather across Ontario.