Ontario to Welcome the First Day of Astronomical Spring With Up to 15-25cm of Snow Between Tuesday & Wednesday
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As we close the chapter on winter with what seemed like an early spring, Ontario is being reminded that winter isn’t going out without a bang. The first day of astronomical of spring arrives on Tuesday, March 19, 2024, at 11:06 PM EDT, but it certainly won’t look like it…
Despite a month filled with unseasonably warm temperatures that saw many regions experience their first 20°C days of the year—quite unusual for this early in the season—the final hours of winter won’t let us forget the season isn’t finished just yet!
A weak system is set to track across Northern and Southern Ontario from Tuesday morning and persist throughout the day. Although this system lacks significant moisture, lake enhancement is expected to amplify snowfall totals in parts of Northeastern Ontario and the regions surrounding Lake Huron and Georgian Bay. We're anticipating overall snowfall accumulation of 10-20cm, with localized areas possibly seeing up to 25cm by Wednesday morning.
While the bulk of the snow will diminish by Wednesday, localized snow squalls could continue to dust the Grey-Bruce and Muskoka regions with an additional 5-15cm of snow by Wednesday's end. However, these higher amounts will be highly localized.
Snowfall has started in parts of Northwestern Ontario, with the system moving south and east overnight. Light snow is expected for most regions throughout Tuesday, except near Lake Superior, Georgian Bay, and Lake Huron, where lake enhancement will result in heavier snowfall.
Particularly northwest of Georgian Bay and east of Lake Superior, Tuesday morning and afternoon will see locally intense snow bands causing reduced visibility and rapid accumulation. These conditions will extend through parts of Northeastern Ontario and into Central Ontario.
By Tuesday night, we expect the system-induced snow to taper off shortly after midnight. However, with cold temperatures prevailing, lake effect snow is likely to continue into Wednesday. This includes a potentially strong snow squall in the Grey-Bruce area, reaching into parts of Simcoe County and the Northern GTA by Wednesday morning.
The snow squall is forecasted to be brief as a wind shift will cause it to move southward and gradually dissipate. Another bout of light snow is anticipated across Southern Ontario on Wednesday afternoon as lake-effect snow becomes more widespread due to the shifting wind direction.
The heaviest snowfall, primarily due to lake enhancement, is expected east of Lake Huron and Georgian Bay. Areas like Owen Sound, Wiarton, Parry Sound, Huntsville, and Sundridge could see totals of 15 to 25cm by Wednesday's end. Owen Sound, in particular, may receive upwards of 30cm, especially if the Wednesday morning squall intensifies as some models suggest.
Neighbouring areas such as Bracebridge, Orillia, Collingwood, Hanover, Kincardine, and Tobermory are projected to receive 10 to 20cm of snow. However, due to the variability introduced by lake enhancement, snowfall distribution will be highly unpredictable, with some locations potentially receiving less than 10cm.
Locations like Goderich, Orangeville, Barrie, Peterborough, and Kingston should brace for 5 to 10cm of snow. These areas will benefit from some lake enhancement, but limited overall moisture will keep totals below 10cm.
Eastern, Southwestern Ontario, and the Golden Horseshoe, including the Greater Toronto Area and Extreme Southwestern Ontario, are expected to see about 5cm of snow over the next two days, with some areas receiving only a few centimetres.
Northeastern Ontario, extending into Northwestern Ontario, could see 15cm to 25cm of snow by the end of Wednesday. This includes Sault Ste. Marie, Wawa, Marathon, Geraldton, Timmins, and Kirkland Lake.
The remainder of Northeastern Ontario will see totals between 10 to 20cm, though regions north of Georgian Bay like Elliot Lake and Sudbury may receive less than 10cm due to diminished lake enhancement.
Northwestern Ontario will experience lesser impacts, with Thunder Bay expecting 2 to 5cm of snow, while Kenora and Dryden will see less than 2cm.
