January Is Ending on a Snowy Note Across Southern Ontario With a System to Dump Up to 15-25cm of Snow on Sunday

UPDATED FORECAST

ISSUED: Saturday, Jan. 28, 2023 (2:00 PM)

Southern Ontario is bracing for yet another impactful snowstorm this weekend, with the latest data shifting the heaviest snowfall totals further south, extending from Kincardine through Collingwood, Muskoka, Bancroft, and Renfrew. Snowfall totals here will range from 15 to 25cm with locally up to 30cm.

Based on the southern shift, we are now expecting less mixing through the Greater Toronto Area (GTA), boosting potential snowfall totals ranging from 5-10cm along the lakeshore and up to 10-15cm further inland. Eastern Ontario is expecting 10-20cm, with slightly less in Prince Edward County due to rain mixing in near the Lake Ontario shoreline. The heaviest snow is expected to occur during the mid to late morning hours on Sunday.

Wet flurries transitioning to rain are expected by mid-morning in Deep Southwestern Ontario and the Niagara region, with snow tapering off by the afternoon as the system exits the region and moves into Quebec.


ORIGINAL FORECAST

NOTE: You can click on the map to open a zoomable image which will be easier to read.


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While the weather started mild and quiet for most of Southern Ontario to begin the first month of 2023, the same can’t be said as we say goodbye to the remaining days of January. We are monitoring yet another potential storm that could bring significant snow to parts of the region on Sunday. This comes only days after a system dumped up to 20-25cm of snow across Southern Ontario on Wednesday leading to hazardous driving conditions and a lengthy cleanup that lasted throughout the week.

With this upcoming event, it will feel like deja vu as we experience similar totals, but the track appears to be slightly further north. This will mean that higher snowfall totals will be found east of Lake Huron and Georgian Bay as lake enhancement becomes a key component in providing extra moisture. While to the south, we could see some mixing in Deep Southwestern Ontario and around the Golden Horseshoe making for a tricky forecast regarding the overall snowfall totals.

We debated on even releasing a forecast this evening as models still disagree on where this mixing line will be located. Some models show less mixing around the GTA, allowing for snowfall totals to exceed 10cm. On the other hand, some models show a switchover to rain (especially closer to the shorelines) which would keep snow totals closer to a few centimetres if anything at all. This is why we emphasize that the forecast right now is very preliminary and will likely change once we get more data tonight and on Saturday.

Snow is expected to start late Saturday or pre-dawn Sunday as the system moves in from the west. The bulk of the snow will fall during the morning hours which is when we expect the worst conditions. It will begin to taper off later in the day with just scattered flurries by the late afternoon through the evening. For Southwestern Ontario, the precipitation will start as wet snow or showers and transition over to rain by the late morning. There is the potential for some brief freezing rain during the transition, but the environment isn’t favourable for widespread freezing rain.

Again as mentioned, the exact snowfall totals are still a little uncertain depending on the track and the extent of rain mixing in and reducing the snow accumulation. We do believe that a fairly widespread zone including the Grey-Bruce region, into Muskoka, Parry Sound and Bancroft could pick up between 15 to 25cm. Some models even indicate locally higher totals exceeding 30cm, but we’ve decided to stick to the 15-25cm range due to the uncertainty. An upgrade to the 20-30cm level in some areas isn’t out of the question.

Accumulation will drop off to the south with expected totals ranging from 10 to 20cm in locations such as Goderich, Northern Simcoe County, Peterborough and the Ottawa Valley. Southwestern Ontario and the GTA are currently on the line between very little snowfall accumulation and 10+ cm of accumulation. We will finalize this in our updated forecast on Saturday and provide a more exact accumulation range once we get a better idea of the extent of the mixing.


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