We are now into December and have been dealing with a rather mild and uneventful past two weeks across Southern Ontario. Our snow here in Barrie has disappeared quite a while ago and temps have been averaging 3 to 6C above normal each day. That is all about to change! A large low pressure system is moving into the Great Lakes and with it will bring a surge of mild air and rain for most of the province. Behind this storm we will see some colder conditions and a return to more normal/slightly below normal December like weather .

Lake effect snow will develop east of Georgian Bay and Lake Huron beginning Tuesday night and should continue into Thursday night, possibly even Friday. This outbreak will be different then the first two from November. The primary wind direction will be from the WSW and W allowing for different areas to be impacted. There will be a time where the winds could shift into the WNW for a short duration bringing some of these bands more south (Wednesday night). One thing I want to highlight is that many would expect given the duration of this event (72 hours) that the amounts would be higher. They won’t and here’s why:

  1. Ample wind sheer keeps bands moving meaning I’m not expecting these bands to stall for hours on end. I guess the benefit is that it will spread the fun out, just not as much.
  2. Lack of true arctic air. Similar in experience to our last two outbreaks, we are lacking the true cold arctic air needed to create super bands. Daytime highs on both Wednesday and Thursday will be near 0C to -2C meaning some of snow will be wet in nature, and the difference between the air temps and the water temps will be less.

So in conclusion, don’t expect epic monster bands of snow. We will have snowsqualls, but we have yet to have an epic outbreak this year so far.

Timeline

Things will get going Tuesday night around midnight and continue to develop through the night. Winds will initially be WSW to ESE bringing the main band off Georgian Bay from Parry Sound northward through Britt, Sunridge, Powassan, North Bay. As far south into Huntsville, Bracebridge should also get some flurries as well as areas just east of Lake Huron from Kincardine across to Dundalk, Shelburne, and Orangeville. Winds should slowly become more Westerly as we go through Wednesday with the most intense band up in Muskoka, somewhere just near of Parry Sound or to the south. Its worth noting this band will be traveling far inland right to the Quebec border near Petawawa.

As we head into Wednesday night the winds will start to become more WNW thus shifting that main band further south down into Bracebridge and Gravenhurst and eventually towards Midland and Orillia. Areas further north will also see a few weaker bands pester around as the energy tries to sink south. Flurries will also get going in the Blue Mountains, Owen Sound, Dundalk Highlands, and up on the escarpment. Through Thursday the bands will continue to impact Simcoe County from Midland down to Orillia and possibly Barrie. Also off Lake Huron we will have to watch a corridor from Owen Sound and Kincardine down towards Shelburne.

Finally as we head into Thursday night into Friday we should start to see a more W flow taking the energy back north.

Accumulations

I will start with my map which shows (in general terms) of what areas I expect to get hit the worst. I will then do a city by city which will include my own thoughts on where the heaviest bands will set up which can’t be shown as easily on a map.

LES Outbreak Dec 5th-8th.jpg

City By City (map updated Dec 5th to include areas NE of Lake Erie and Lake Ontario where we will likely see 3-8cm of snow, locally 10cm if things stall out a bit longer)

Goderich: 2-8cm

Kincardine: 10-15cm

Sauble Beach: 10-15cm

Owen Sound: 15-25cm

Kitchener: Trace-5cm

Collingwood/Blue Mountains: 12-20cm

Tobermory: 25-35cm

Dundalk/Shelburne: 8-15cm

Midland: 10-20cm

Orillia: 10-20cm

Barrie: 8-15cm

Alliston: Trace-5cm

Gravenhurst: 25-40cm

Bracebridge: 25-40cm

Huntsville: 35-55cm

Rosseau: 35-60cm

Parry Sound/Britt: 35-60cm

North Bay: 8-15cm

Powassan: 20-40cm

Sunridge: 25-50cm

Petawawa/Pembroke: Trace-6cm

Fort Erie/NE Lake Erie Shoreline: 5-15cm

Prince Edward County: 5-15cm

Kingston: 4-10cm

That’s all for now. I will fine tune this as more info comes in, but right now its pretty clear who’s going to get hit the worst.

 

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