Southern Ontario: Fall Weather Hazards Outlook for Tuesday, November 30, 2021

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Forecast Discussion

A fairly weak system will sweep across Northeastern Ontario and into parts of Central Ontario during the day on Tuesday and into the evening. Not much accumulation is expected with maybe a few centimetres of fresh snow. However, there is some indication that the system could be enhanced by Georgian Bay bringing slightly higher totals through the Muskoka, Parry Sound and Algonquin Park area. Accumulation here could range from 5-10cm with most of the snow coming later in the day and especially during the evening hours. A few localized spots may pick up 15cm if we see really organized lake effect bands developing within the system snow, but it doesn’t seem likely.

The rest of Southern Ontario will see snow throughout the day on Tuesday with a focus on the morning for Southwestern Ontario and later in the day for Eastern Ontario. At this point, we don’t believe anyone outside of the areas east of Georgian Bay will see more than 5cm so we have not included that accumulation in the outlook. Just keep in mind that you should expect some winter weather conditions everywhere, but it won’t be very impactful.

Southern Ontario: Fall Weather Hazards Outlook for Sunday, November 28, 2021

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Forecast Discussion

A system currently bringing accumulating snowfall to parts of Southwestern Ontario during the evening on Saturday is expected to merge with a system over Northern Ontario as it drops southward across Southern Ontario. This will spread light to moderate steady snowfall through areas east of Lake Huron and into the Golden Horseshoe during the morning on Sunday and continuing into the afternoon.

Accumulation won’t be overly significant with general amounts ranging from 5-10cm (although a few pockets could pick up slightly higher amounts if we see some lake enhancement) by the end of Sunday when the snow is expected to taper off. Regardless, this will likely be the largest snowfall much of the GTA and surrounding regions outside of the snowbelt have seen this season thus far. If you’re travelling on Sunday, leave plenty of time to get to your destination as roads will likely be slushy or snow-covered.

Southern Ontario: Fall Weather Hazards Outlook for Saturday, November 27, 2021

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Forecast Discussion

A fast-moving system will sweep across Extreme Southwestern Ontario during the afternoon on Saturday and continue through the evening. This will bring the first accumulating snowfall of the season to locations such as Windsor, Sarnia and Chatham. General snowfall accumulation between 4-8cm is possible with locally up to 10cm, but it’s unlikely many areas will see this. The snowfall will taper off just after midnight as the system moves over Upstate New York. Additional snowfall is possible on Sunday with another system which will be covered in Sunday’s outlook if necessary.

Southern Ontario: Fall Weather Hazards Outlook for Friday, November 26, 2021

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Forecast Discussion

A weak system that has been bringing scattered showers to parts of Southern Ontario throughout the day on Thursday is expected to linger into Friday. However, some of the coldest air of the season will flow into the region overnight and early Friday morning which will drop temperatures to well under the freezing mark. This will allow for the rain showers to transition over to wet flurries and light snowfall.

This system is lacking in terms of moisture so significant accumulation isn’t expected outside of the snowbelt except for higher elevations of Central/Eastern Ontario. Some icy road conditions can also be expected during the morning commute on Friday due to the sharp drop in temperatures and earlier rainfall. But the drop isn’t significant enough to be considered a flash freeze.

As for the areas that will see the highest totals, this will be those along the Lake Huron and Georgian Bay shorelines as lake enhancement and embedded snow squalls will help boost the totals above the general system snowfall. The focus will be on areas southwest of the lakes including Goderich, London, Collingwood and Angus where between 10-15cm of snowfall is possible and maybe locally as much as 20cm by the end of Friday.

Further north, more moisture across Algonquin Park and into the Ottawa Valley will allow for snowfall accumulation of between 10-15cm in the higher elevations and around 5-10cm for other areas. Aside from those regions, the rest of Southern Ontario is expecting to see less than 5cm of accumulation on Friday. The snow will come to an end late Friday.

Northern Ontario: Fall Weather Hazards Outlook for Thursday, November 25, 2021

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Forecast Discussion

An area of moderate to heavy persistent snowfall will move across Northeastern Ontario starting in the afternoon on Thursday and continue through to Friday morning. It will also be accompanied by some strong wind gusts between 40-60km/h which may result in localized blowing snow and near-zero visibility out on the roads The hardest-hit area appears to be the region just to the southwest of the Quebec border including Sudbury, Englehart and Timmins where total accumulation between 10-15cm is expected by early Friday morning. A few localized spots may pick up slightly more than 15cm. Outside of this zone, the rest of Northeastern Ontario will see around 5-10cm of snow. As mentioned, the snow will taper off by noon on Friday.

Northern Ontario: Fall Weather Hazards Outlook for Monday, November 22, 2021

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Forecast Discussion

Heavy snow from a system currently tracking across Northern Ontario will continue into Monday morning. This will bring the potential for up to 10-15cm of additional snowfall accumulation on Monday mainly through Northeastern Ontario. There will also be some snow squalls off Lake Superior affecting the Wawa and Sault Ste. Marie during the morning which may result in localized totals between 10-20cm in the hardest-hit locations. All snow will come to an end by late Monday, but some flurries may continue throughout the day.

Northern Ontario: Fall Weather Hazards Outlook for Sunday, November 21, 2021

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Forecast Discussion

Light to moderate snowfall is expected to spread across Northern Ontario throughout the day on Sunday starting with the more western part of the province earlier in the day and reaching Northeastern Ontario by the late afternoon. Snowfall rates won’t be particularly impressive due to the lack of moisture that this system has to work with. We’re expected general snowfall totals by the end of Sunday between 5-10cm for much of Northern Ontario with locally up to 15cm in some pockets. Under 5cm is expected for the Thunder Bay area as they’ll miss most of the precipitation and the North Bay, Elliot Lake and Sudbury region will see more of a rain/snow mix which should keep accumulation under 5cm.

In addition to the system snow, some lake effect snow and localized snow squalls could develop east of Lake Superior late Sunday. The corridor between Wawa and Sault Ste. Marie may see locally as much as 20cm when combining the system and lake effect snow. Snow will linger into Monday which could deliver another 5cm of snow accumulation with locally 10-15cm in the lake effect zone east of Lake Superior. This will be covered in Monday’s outlook.