High-Impact Snow Squall Event Could Bring Up to 100 cm and Blizzard Conditions to Southern Ontario’s Snowbelt Starting Monday
/Chilly Arctic air has begun sweeping into Southern Ontario this weekend, marking the return of lake-effect snow activity off the Great Lakes. While snow squalls on Sunday have been relatively limited, they are expected to organize and intensify as the evening progresses.
Intense snow squalls are set to impact areas around Lake Huron and Georgian Bay from Monday through Tuesday. Portions of the Niagara region and Prince Edward County may also experience squalls driven by activity off Lake Ontario and Lake Erie.
Moderate wind gusts of 50-60 km/h are likely to develop on Monday morning. When combined with heavy snow, these winds could cause blowing snow and localized blizzard-like conditions in some areas. Poor travel conditions are anticipated, with road closures possible throughout Monday and into Tuesday.
The Bruce Peninsula is expected to bear the brunt of these squalls. A prolonged and intense squall is likely to lock in over the region from Monday afternoon through Tuesday, with snowfall totals potentially approaching 100 cm.
Other areas along the Lake Huron shoreline, as well as parts of Simcoe County and Muskoka, could see snowfall accumulations of 25-50 cm by the end of Tuesday.
This forecast also extends to the southern tip of Prince Edward County, south of Picton, where a Lake Ontario squall could drift across the county before moving into New York State.
As of Sunday evening, a pocket of heavy snow over Lake Ontario is affecting northern Niagara. Meanwhile, a squall over Lake Huron has diminished but is expected to reorganize by midnight.
According to the latest model data, a very narrow yet intense squall is likely to develop over the Goderich area overnight. Snowfall rates could reach 10-15 cm per hour, with higher ratios due to colder temperatures.
This could result in rapid snow accumulation across Huron County, particularly in the Goderich region, through Monday morning.
There is some uncertainty regarding how far inland this squall will extend. However, it could potentially stretch into the Kitchener area, through Burlington and Hamilton, and become further enhanced as it moves back onshore over the Niagara region via Lake Ontario.
By Monday afternoon, a shift to more westerly winds is expected, pushing the Lake Huron squall towards the Bruce Peninsula. The squall is predicted to stall over the northern and central parts of the peninsula by Monday evening.
Wind gusts will strengthen throughout Monday afternoon and evening, reaching 50-60 km/h in some areas. These winds are likely to create blowing snow and near-zero visibility, making travel nearly impossible east of Lake Huron. While conditions may not officially meet blizzard criteria, they will be very close.
Model projections diverge on the squall's movement after it crosses Georgian Bay. Canadian models suggest a variable wind direction could cause the squall to curve northward into Muskoka and Parry Sound instead of continuing east.
Meanwhile, the American model indicates a more southerly trajectory, targeting Midland, Honey Harbour, and Washago. This model also suggests secondary squall activity could impact southern Bruce-Grey areas, including Port Elgin and Owen Sound.
Both models agree that upper-level winds will likely keep the squall close to the Georgian Bay shoreline. This may spare inland areas like Bracebridge, Gravenhurst, and Orillia from the heaviest snowfall, though the squall's reach could still surprise some locations.
There is also uncertainty regarding squalls over Lake Ontario and Lake Erie. While these squalls may drift northward into Fort Erie and southern Prince Edward County, they could remain concentrated south of the border.
Snow squall activity is expected to remain stationary through Monday night into Tuesday morning, with snowfall rates of 5-10 cm per hour possible.
The Bruce Peninsula squall may gradually drift southward on Tuesday afternoon, although it is expected to weaken slightly as wind directions shift. Despite this, squalls will likely persist over the Grey-Bruce region throughout Tuesday.
Snow squalls are anticipated to continue into Wednesday, although their intensity and direction remain uncertain. Southwesterly winds may develop, which could direct squalls over the Bruce Peninsula and extend into the Parry Sound region.
UPDATED FORECAST (3:30 PM - JAN 20, 2025)
Muskoka, before you grab a pitchfork to take out your snow frustrations, you might want to trade it in for a snow shovel—you’re going to need it. 😉
The latest model data this morning doesn’t bring good news for those in Muskoka hoping for a break from the snow. How does another 50-100 cm sound?
In our initial forecast, we mentioned that model data suggested snow squall activity would stay primarily along the Georgian Bay shoreline. This meant that areas further inland, such as Bracebridge, Port Carling, and Gravenhurst, could avoid the brunt of the snow.
Unfortunately, the newest data paints a different picture. This morning’s updates indicate that snow squalls will push much further inland than originally expected. The models also show an increase in the intensity of these squalls, starting late this afternoon and continuing all day through Tuesday.
As a result, we’ve made adjustments to our forecast, extending the zone of heavy snow further inland east of Georgian Bay. Additionally, we’re now introducing a 50-100 cm snowfall zone for Muskoka, similar to what was previously focused over the Bruce Peninsula.
Locations such as Port Carling, Rosseau, Port Sydney, and Bracebridge are now directly in the crosshairs, with the potential for up to 100 cm of snow by the end of Tuesday. Meanwhile, the forecast for the Bruce Peninsula—covering Tobermory, Lion’s Head, and Wiarton—remains unchanged, with totals still expected to reach 50-100 cm.
For the rest of Muskoka, including Huntsville and Gravenhurst, as well as Parry Sound and Midland, snowfall accumulations of 25-50 cm are likely. This range also applies to the Owen Sound, Meaford, and Port Elgin areas.
You might notice a slight reduction in the forecast east of Lake Huron. This adjustment reflects snowfall that already occurred last night and early this morning, especially in areas like Goderich. These regions are expected to see an additional 15-25 cm of snow by the end of Tuesday.
Our forecast for Fort Erie and Prince Edward County remains unchanged. Squall activity off Lake Erie and Lake Ontario could bring 15-25 cm of snow to the southern Niagara region, including Fort Erie. Meanwhile, southern Prince Edward County, particularly south of Picton, could see totals ranging from 25-50 cm.
See below for our Lake Ontario and Lake Erie forecast.
PREVIOUS FORECAST:
Given the frequent mention of the Bruce Peninsula in this forecast, it’s no surprise that this region is expected to receive the most snowfall from this event.
Accumulations of 50-100 cm are projected for areas including Tobermory, Lion’s Head, and Wiarton. Some locations may even exceed 100 cm if the squall remains stationary for an extended period.
Along the Lake Huron shoreline, areas such as Goderich, Point Clark, Kincardine, Port Elgin, Chatsworth, Owen Sound, and Meaford are likely to see 25-50 cm of snowfall by Tuesday’s end. As with most snow squalls, localized variations in totals are expected based on the squall's exact path.
Similar snowfall amounts of 25-50 cm are possible along the eastern Georgian Bay shoreline, including Midland and MacTier. However, these totals will be highly localized, as the squall’s path is still uncertain.
Further inland, areas east of Lake Huron, such as Listowel, Hanover, and Flesherton, are forecasted to receive 15-25 cm of snow. Western Muskoka and Simcoe County, including Port Carling, Bala, Washago, and Gravenhurst, could also see 15-25 cm.
Brief periods of heavy snow are possible in the western GTA, Kitchener, Barrie, and parts of Muskoka, leading to localized accumulations of 5-15 cm. Most areas will likely remain on the lower end of this range, but isolated pockets could approach 15 cm.
The St. Catharines and Niagara-on-the-Lake regions are currently experiencing locally heavy snow, which is expected to continue overnight. By Monday morning, total snowfall, including amounts already fallen, could range from 15-25 cm.
Fort Erie may also see 15-25 cm of snow if the Lake Erie squall edges far enough north. However, there is a possibility that the squall will remain south of the border, resulting in minimal accumulation on the Canadian side.
In Prince Edward County, the southernmost tip exposed to Lake Ontario could see 25-50 cm of snow. Slight shifts in the squall’s position could significantly impact snowfall totals, with Picton potentially receiving 15-25 cm under favourable conditions.
The rest of Southern Ontario is expected to see less than 5 cm of snow from this event. The Ottawa Valley and areas in deep southwestern Ontario will likely experience the least snowfall, with accumulations of less than 2 cm by Tuesday.