Snow Day (Bus Cancellation) Outlook for Tuesday, November 23, 2021

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Lake effect snow and localized squalls will continue around the Lake Huron and Georgian Bay shoreline overnight into Tuesday. However, the squalls are expected to weaken somewhat by the early morning so conditions at the time won’t be as bad as compared to earlier in the night. Despite that, the significant accumulation between 15-30cm still to come by the morning will likely result in some school bus cancellations through the affected area as roads will still be snow covered along with localized blowing snow.

The highest probability ranges from 50-75% which includes Simcoe County and portions of Grey-Bruce counties directly near Lake Huron and Georgian Bay. Some lake effect snow will continue to linger through the morning hours in the regions we've given the 75% chance of a snow day. Although it might not be enough as this region appears to be more stringent when calling a snow day even with a snow squall warning from Environment Canada in effect. The further away from the shorelines, the lower the chance of a snow day as this will be mainly contained to the traditional snowbelt.

If there are any cancellations tomorrow morning, you can be sure we’ll be up bright and early beginning at 6 AM with our bus cancellations live blog to keep you updated.

Disclaimer: Instant Weather has zero authority when it comes to bus and school closures. It is completely up to the school boards, bus companies, and local authorities as well as being up to parents to decide what is best for their children. This is simply our best guess based on our forecast. Also note that due to the current pandemic, some school boards have changed their policies on school bus cancellations. Some will continue the school day in a virtual format should there be school bus cancellations - check with your local board for more details.

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.

Snow Day (Bus Cancellation) Outlook for Monday, November 22, 2021

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Intense snow squalls are expected to develop early Monday morning and continue throughout the day for areas around parts of Lake Huron and Georgian Bay. This will bring reduced visibility and rapid snowfall accumulation making for very poor driving conditions in the affected region. As a result, it’s hard to see how school buses will be able to run safely through Grey, Bruce and Simcoe Counties so we’ve given those areas a 75-90% chance of a snow day.

Surrounding regions including Parry Sound, Muskoka, Kawartha Lakes, North Durham, Dufferin and North Huron/Perth counties have the chance of seeing a snow day ranging from 25-50%, but it’s not guaranteed depending on local road conditions in the morning. Other areas throughout the GTA, Kitchener/Waterloo region and London likely won’t see a snow day, but an isolated cancellation can’t be ruled out mainly due to the potential for some icy roads.

If there are any cancellations tomorrow morning, you can be sure we’ll be up bright and early beginning at 6 AM with our bus cancellations live blog to keep you updated.

Disclaimer: Instant Weather has zero authority when it comes to bus and school closures. It is completely up to the school boards, bus companies, and local authorities as well as being up to parents to decide what is best for their children. This is simply our best guess based on our forecast. Also note that due to the current pandemic, some school boards have changed their policies on school bus cancellations. Some will continue the school day in a virtual format should there be school bus cancellations - check with your local board for more details.

Arctic Air To Kick Off an Impactful Snow Squalls Event Between Monday and Tuesday With 15–30cm of Snow Accumulation; Locally Up to 40cm for Grey, Bruce and Simcoe Counties

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The first push of frigid Arctic air will bring temperatures well below the freezing mark through Southern Ontario to start off the week. This cold air will also turn the lake effect snow machine onto full blast through parts of the snowbelt starting Monday morning and lasting through to Tuesday. Intense snow squalls with the worst conditions found during the day on Monday and overnight into early Tuesday will set up off Georgian Bay and Lake Huron in a northwesterly flow and stretch quite far inland at times. There will also be some strong wind gusts between 40-60km/h resulting in localized blowing snow and near-zero visibility out on the roads which will make travel near impossible through the affected regions.

It’s still a little uncertain on the exact placement of the snow squalls which will determine who sees the most snowfall accumulation from this event. Model data earlier in the day showed one main band off Lake Huron somewhere near Saugeen Shores and stretching as far inland as the Hwy 400 corridor south of Barrie. However, the most latest data shows a clearly northern shift in the location of the bands which would allow for some further enhancement from Georgian Bay. This would put the squall from Lake Huron over Wiarton/Owen Sound and it’ll move across Georgian Bay picking up more moisture before pushing into Simcoe County and Northern Grey County. Some additional activity. For our forecast, we’re going with the latest data, but keep in mind that we may have to make adjustments to our map if it shifts back. We will update it by the end of Sunday evening at the latest based on the evening model data.

Snow squalls and lake effect snow will develop off Lake Huron and Georgian Bay early Monday morning with a primarily westerly flow which will affect the Bruce Peninsula and into the Muskoka/Parry Sound region. This activity will be fairly weak so significant accumulation isn’t expected with maybe 5-10cm max before it shifts southward later in the morning. The lake effect snow will further intensify into a strong squall towards the late morning hours as it reaches the Northern Simcoe County region.

Now, the key thing will be if it stabilizes and stops shifting to the south locking into somewhere through Southern Bruce Peninsula, Meaford, Owen Sound, Simcoe County and areas directly east of Lake Simcoe. If it does this then we could easily see snowfall totals ranging from 20-40cm by the evening in localized pockets with general totals between 10-25cm. Heavy snowfall could be found quite far to the east as the squall will have a lot of fetch and strong winds to push it far inland. Locations such as Lindsay, Kawartha Lakes and Peterborough who traditionally don’t see a lot of lake effect snow may get up to 10-20cm along with poor driving conditions.

After the dinner hour, we expect the squall to move southward again with the enhancement off Georgian Bay being shut off and it becoming mainly fueled by Lake Huron. The fetch won’t be as intense compared to earlier in the day so the lake effect activity will be more contained to the Lake Huron shoreline. The most significant impact from this squall late Monday and into the overnight hours will be felt through the Saugeen Shores, Kincardine, Hanover, Chatsworth and Minto region where locally up to 20-40cm is possible by Tuesday morning. Some less organized lake effect snow is also possible off the southeastern shoreline of Georgian Bay early Tuesday morning with a focus on the Collingwood/Angus area potentially stretching across Hwy 400, but the Lake Huron squall will be the main event. All lake effect snow and squalls should taper off by the afternoon on Tuesday.

Please note that the accumulation map that we provided in this forecast is meant to show the maximum accumulation possible from the snow squalls. Due to the localized nature of lake effect snow, one location can get 50cm while just down the road could see less than 5cm so it’s quite hard to factor these hyper-local dynamics into the forecast. Lake effect snow is probably one of the most difficult things to forecast as just a slight change in the wind direction can shift the heaviest snow in a different direction. Even if we’re forecasting up to 40cm doesn’t mean you’re guaranteed to see it and you may see nothing at all. Just the potential is there should the environment line up. Similar to tornadoes, they don’t affect everyone within the risk zone. Sometimes the lake effect snow just doesn’t materialize to the extent that we’re expecting and sometimes they’re much stronger resulting in overachieving snowfall totals. We are continuously going over the latest update and will revise our map later Sunday evening if needed.

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

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Forecast Discussion

Accumulating snow from Sunday may continue into early Monday through Northeastern Ontario where an additional 5-10cm is possible, but there is low confidence on the exact locations impacted. Snow squalls may also continue east of Lake Superior.

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

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Forecast Discussion

Snow squalls are expected to affect areas east of Lake Huron along with regions southeast of Georgian Bay during the day on Monday. This could bring rapid snowfall accumulation and near-zero visibility. However, there is some uncertainty on the placement of these squalls which will determine who sees the highest totals. We will have a full snow squall outlook published sometime on Sunday.

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.

Snow Squalls To Bring Up to 20cm of Snow to Areas East of Lake Huron and Georgian Bay Between Thursday Evening and Friday Morning

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Colder air returns to Southern Ontario after a brief shot of mild weather which has resulted in the development of lake effect snow late Thursday and is expected to further intensify into squalls by the evening.

The focus of these squalls will be on a zone east of Georgian Bay with the heaviest accumulation in locations such as Parry Sound, Port Carling, Bracebridge, Gravenhurst and Miden. There will also be some less organized squalls off Lake Huron with higher amounts further inland over the Hanover, Minto, Wingham and Listowel area. Total accumulation could approach the 20cm mark locally with general amounts around 10-15cm.

Those closer to the shoreline will see lower amounts due to temperatures staying above the freezing mark which will mean the snow will struggle to accumulate. The lake effect activity will drift southward during the morning on Friday bringing the heavy snow to locations such as Collingwood, Wasaga, Angus, Goderich and Stratford. However, the squalls won’t last long until fizzling out by the afternoon hours so accumulation should be limited to around 5cm with maybe some localized pockets picking up to 10cm.

Snow squalls can cause quite dangerous driving conditions through the affected regions with near-zero visibility and rapid snowfall accumulation. It is highly recommended that you avoid travel during the evening and overnight hours if you can. Otherwise please leave lots of time to get to your destination safely! The morning commute will likely be impacted, but conditions should be a little better than compared to the overnight hours. School bus cancellations are possible Friday morning which we will cover in our snow day forecast to be issued Thursday evening.

Northern Ontario: Fall Weather Hazards Outlook for Thursday, November 18, 2021

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Forecast Discussion

Snow squalls are possible off the Eastern shoreline of Lake Superior starting early Thursday morning and continuing throughout the day. The heaviest snowfall rates will be found between Sault Ste. Marie and Wawa where travel conditions will be quite poor during the morning and afternoon with near-zero visibility. We expect to see the squalls will slowly weaken by late Thursday and be fully done around the midnight hour.

Total accumulation in the hardest hit zone including Wawa and just to the north of Sault Ste Marie could approach up to 20cm with general amounts between 10-20cm. Surrounding areas that include Marathon, Chapleau and Sault Ste. Marie can expect locally up to 5-10cm by the end of the day although not everyone will see even a flake of snow due to the localized nature of lake effect snow.

Southern Ontario: Fall Weather Hazards Outlook for Thursday, November 18, 2021

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Forecast Discussion

The lake effect machine will kick back into gear to end off the week for Thursday and affect areas mainly to the east of Georgian Bay. We will see the development of lake effect snow beginning Thursday afternoon around the Parry Sound and Muskoka region. Although they won’t really get organized until after the dinner hour when some localized strong squalls may develop and continue into the overnight hours. A few hours of heavy snow is possible through the Hwy 400 and Hwy 11 corridor between Parry Sound to Honey Harbor and Huntsville to Gravenhurst with poor travel conditions during the evening.

Localized totals of up to 15cm can’t be ruled out should the squall lock into a particular area for a few hours. A more general estimate would be around 5-10cm, but it’s hard to predict as these squalls are so localized. There will also be some less organized activity off Lake Huron that will bring around 5cm at most with locally up to 10cm for the Hanover and Meaford area.

The wind direction will shift bringing the weakening squall southward into parts of Simcoe County and Kincardine/Listowel area early Friday morning. They will fully dissipate by late Friday morning so accumulation should be limited on Friday.

Northern Ontario: Fall Weather Hazards Outlook for Thursday, November 18, 2021

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Forecast Discussion

Lake effect snow and localized squalls are possible east of Lake Superior on Thursday which could bring up to 10-20cm to the Marathon and Wawa area. However, confidence in the exact location of the lake effect snow is low at this point.

Southern Ontario: Fall Weather Hazards Outlook for Thursday, November 18, 2021

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Forecast Discussion

Lake effect snow may develop during the afternoon on Thursday and continue into Friday for areas east of Lake Huron and Georgian Bay. However, confidence in locations impacted and the exact accumulation is unclear at this point.