***NOTE: YOU CAN CLICK ON THE MAP TO OPEN A ZOOMABLE IMAGE***

As January 2025 draws to a close, Southern Ontario’s weather has varied greatly depending on the region.

Snowbelt areas near Lake Huron and Georgian Bay have been bombarded by persistent lake-effect snow over the past couple of weeks. Meanwhile, Eastern and Deep Southwestern Ontario have seen little snow this month, as no significant systems have impacted those areas.

That pattern is about to shift, with an Alberta Clipper poised to bring a widespread snowfall event across Southern Ontario. This system is expected to deliver 10 to 20 cm of snow to Eastern, Central, and Southwestern Ontario over the next 24 hours, including the snowbelt regions.

In addition to the clipper, snow squalls are forecast to develop Wednesday afternoon and continue into the evening. Combined system snow and lake effect snow could bring an additional 20 to 30 cm to areas east of Lake Huron between Tuesday and Wednesday.

**PRECIPITATION TYPE** - MAP FROM WEATHERBELL

Snowfall from the clipper has already begun moving into Southwestern Ontario near Lake Huron as of late Tuesday afternoon.

Moderate to heavy snow will spread eastward through the evening, with the heaviest snow expected in the Greater Toronto Area (GTA) and Central Ontario during the late afternoon and early evening.

Localized heavier snow is likely along the Lake Huron and Georgian Bay shorelines, particularly over the Bruce Peninsula, where lake enhancement will add extra moisture to the system.

For Southwestern Ontario, snowfall will begin to taper off by the evening and should exit areas southwest of Lake Simcoe by midnight.

Central and Eastern Ontario will continue to see snow through the early overnight hours, with the Ottawa Valley potentially experiencing snowfall until Wednesday morning, tapering off around sunrise.

**HOURLY SNOWFALL RATE/intensity** - MAP FROM WEATHERBELL

Following the system’s departure, lake effect snow is expected to ramp up over Lake Huron and Georgian Bay.

Models indicate disorganized snow bands developing off Lake Huron on Wednesday afternoon, impacting areas like Grey, Bruce, Huron, and Perth counties. These bands may occasionally extend as far as Kitchener and Hamilton.

Additionally, a snow squall may form southeast of Georgian Bay, bringing heavy snow to the Barrie and Innisfil areas Wednesday afternoon. The intensity and duration of this squall remain uncertain.

By Wednesday evening, activity over Lake Huron may consolidate into a stronger squall targeting the corridor between Southampton and Kincardine, potentially extending to the Hanover area. This squall could lead to rapid snowfall accumulation before gradually weakening after midnight.

The highest snowfall totals over the next 24 hours are expected in the Grey-Bruce region.

Communities such as Port Elgin, Kincardine, Owen Sound, Chatsworth, Mildmay, and Hanover are forecast to receive 10 to 15 cm of snow from the clipper and an additional 10 to 20 cm from lake effect snow on Wednesday.

This could bring total accumulations to 20 to 30 cm, with isolated pockets potentially exceeding 30 cm.

Across Central and Eastern Ontario, Alberta Clipper snowfall is generally expected to range from 10 to 15 cm. Areas southeast of Georgian Bay, including Barrie, may see near 20 cm due to the added snow from Wednesday afternoon’s localized squalls.

Lower totals are expected in the GTA and Niagara regions, as the system’s moisture will primarily focus further north, and lake enhancement will not play a role.

Snowfall amounts in the GTA are expected to range from 4 to 8 cm, with Hamilton and the Niagara corridor seeing even less at 2 to 4 cm.

Deep Southwestern Ontario, including Windsor, Chatham, Sarnia, and London, will see little to no snow from this system. London could receive a few centimetres, while Windsor may only see a trace.

Looking ahead, we are monitoring a potential system moving in on Friday, which could bring snow and freezing rain to parts of Southern Ontario. Stay tuned for updates.