Snowy Start to 2025 in Ontario’s Snowbelt; Squalls Could Deliver Up to 50cm of Snow by End of Week
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As we kick off the New Year across Ontario, we’re starting off with a blast of cold Arctic air that moved into the region over the past 24 hours. With this chilly air comes the inevitable return of lake-effect snow in the traditional snowbelt areas surrounding Lake Huron, Georgian Bay, and Lake Superior.
Strong snow squalls are anticipated to develop Wednesday evening and are likely to persist through Thursday and into Friday. These squalls are expected to bring intense snowfall rates of 5-10 cm per hour, along with near-zero visibility that will make travel nearly impossible in the hardest-hit areas.
The main focus for this lake effect activity will be in parts of Huron, Perth, Grey, Bruce, and Simcoe counties. Depending on where these narrow snow bands establish, localized accumulations could approach or exceed 50 cm by week’s end, with additional snowfall possible through the weekend as the lake effect machine remains active.
HOURLY SNOWFALL RATE/intensity - MAP FROM WEATHERBELL
Disorganized squalls are expected to begin forming off Lake Huron and Georgian Bay late Wednesday evening or around midnight. According to the latest data, multiple bands could develop off Lake Huron, with one possibly targeting areas south of Owen Sound.
Another band may stretch from Goderich inland towards Stratford and St. Marys, just north of London. However, there remains some uncertainty about where exactly these squalls will set up, which will determine the heaviest snowfall locations.
For Georgian Bay, models show differing timelines. One suggests squall activity could begin just after midnight, while another predicts development near sunrise on Thursday. If squalls form, areas like Wasaga Beach and Barrie could be affected overnight.
Overnight, the bands that do form may shift around and dissipate periodically, spreading snowfall over a broader area. If a squall locks into place unexpectedly, snowfall can accumulate rapidly in a short time.
HOURLY SNOWFALL RATE/intensity - MAP FROM WEATHERBELL
The event is expected to intensify by mid to late Thursday morning as the northern squall off Lake Huron drifts northward, potentially crossing the Bruce Peninsula and reconnecting over Georgian Bay. This setup could lead to a rare "multi-lake connection," allowing the squall to draw moisture from a long stretch of open water.
The result would be heavy snowfall affecting areas such as Owen Sound, Collingwood, Wasaga Beach, and Barrie, with possible extensions into Durham Region and southern Kawartha Lakes.
Another squall off Lake Huron could extend inland into Huron and Perth counties, with potential impacts as far as Kitchener-Waterloo. While intense snowfall could occur, squalls are notoriously narrow, and not all areas will be directly affected.
HOURLY SNOWFALL RATE/intensity - MAP FROM WEATHERBELL
By late Thursday afternoon, snow squalls off Lake Huron may weaken as the wind shifts more westerly, reducing the available lake surface from which the squalls can pull moisture. The Georgian Bay squall, however, could continue intensifying and shift northward, potentially impacting areas like Midland and Orillia while giving Barrie a break.
There remains uncertainty regarding the squall's position, with some models suggesting it may remain south of Orillia. If the squall locks in place overnight, areas such as Simcoe County and southern Kawartha Lakes could see prolonged periods of heavy snow, leading to extremely poor travel conditions, potential road closures, and significant snowfall accumulations.
By late Friday morning, shifting winds are expected to push the Georgian Bay squall southward, potentially dissipating it by midday. However, lake effect activity off Lake Huron may persist southeast of the lake into areas like Kitchener and London through Friday afternoon and evening.
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The hardest-hit regions from this event will likely include Grey-Bruce and southern and central Simcoe County, including Wasaga Beach and Barrie. Snowfall totals in these areas could range from 25 to 50 cm by Friday night.
Some localized spots, particularly between Barrie and Orillia, may see totals exceeding 50 cm, with the potential for as much as 75 to 100 cm. However, model disagreement prevents us from confidently forecasting such extreme totals.
It’s important to note that snow squalls are highly localized phenomena, often only a few kilometres wide. While our forecasts aim to highlight the most likely zones, the reality is that squalls can shift unexpectedly, meaning not every location in a forecasted zone will see the same impacts.
Surrounding areas, including Orillia, Lindsay, Fenelon Falls, and Port Perry, could see localized snowfall of 15-25 cm from the Georgian Bay squall, with totals tapering quickly outside of this zone. Peterborough and areas along the Lake Ontario shoreline between Oshawa and Brighton may see 5-15 cm.
For regions east of Lake Huron, a narrow band from Goderich to Wingham and Listowel could see 25-50 cm of snow, with some extension into Kitchener, where totals may approach 15-20 cm. However, the exact setup will depend on the squall’s inland reach.
Elsewhere, the Golden Horseshoe could see a few centimeters of snow from brief, heavy bursts of lake effect activity, but no significant accumulations are expected. Areas north of Bracebridge, east of Peterborough, and south of Woodstock are likely to see little to no snow.
As always, lake effect snow forecasts carry inherent uncertainty. While many areas may receive less snow than forecasted, those directly in the path of these intense squalls could see the full brunt of the snowfall. Be prepared for rapidly changing conditions, and avoid non-essential travel in the hardest-hit zones.
Snow squalls are also expected to affect regions east and southeast of Lake Superior in Northern Ontario starting Wednesday evening. These squalls will continue to persist throughout the day on Thursday before shifting south of the border.
The Sault Ste. Marie region appears to be in the bullseye and could see localized snowfall totals between 25 to 50cm by the time the snow tapers off late Thursday.
