Widespread Strong Severe Thunderstorm & Tornado Risk for Southern Ontario on Wednesday
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The multi-day severe weather threat continues in Southern Ontario for Wednesday, with what could be the strongest risk of the year so far. Several rounds of storms are expected this afternoon and early evening throughout Central and Eastern Ontario, along with the Golden Horseshoe.
The biggest concern is currently focused on an area stretching from Lake Simcoe northeast into Muskoka and Algonquin Park. All the latest data points to a very potent environment developing early this afternoon, which would be favourable for storms to quickly become severe with large hail, destructive wind gusts, and tornadoes.
As a result, our forecast includes the first ‘strong’ (level 3) severe risk of the season in Ontario. This is primarily due to the wind threat, which could be quite widespread and intense as we see multiple lines of storms. One or two tornadoes are also possible within the ‘strong’ and ‘slight’ severe risk zones, which encompass almost all of Southern Ontario except for Southwestern Ontario.
The ‘strong’ severe risk includes Kitchener, Orangeville, Barrie, Orillia, Collingwood, Midland, Bracebridge, Parry Sound, Huntsville, Sundridge, Bancroft, Algonquin Park, Deep River And Pembroke.
The tornado threat is highest across Central Ontario, where isolated severe supercells could develop. However, tornadoes could occur anywhere within the severe risk zones, so remain vigilant regardless of your location.
Timing is tricky to nail down as we are looking at multiple rounds of storms, and models are not in full agreement on when and where these storms will occur. Here is a rough estimate of each round of storms, though this may shift throughout the day.
Current indications show isolated storms developing between Lake Huron and Georgian Bay along the Goderich to Parry Sound corridor. This could happen as early as 12-1 PM as the environment builds ahead of these storms.
They are expected to track into Simcoe County and regions east of Georgian Bay by early afternoon. At this point, they will likely become severe, tracking into the Muskoka, Parry Sound, and Sundridge regions.
All severe threats are possible as they track northeast towards Algonquin Park, Bancroft, and eventually the Quebec border. Large hail and tornadoes are possible within these clusters of storms, especially early in their lifespan before they begin to bow out and become more of a wind gust threat.
For those who see this first line of storms, don’t be caught off guard! More storm development is expected across Georgian Bay and to the south around Lake Simcoe throughout the afternoon hours.
Another cluster of storms in the late afternoon may follow a similar track as the earlier storms through Simcoe County, Kawartha Lakes, Muskoka, and Bancroft. This line of storms will continue across Central Ontario and potentially into the Ottawa Valley by dinner time.
Some isolated storms may also form over Lake Erie and potentially track into the Niagara region during the afternoon. Additionally, we are seeing some indications of a few isolated storms forming just before sunset around 6 to 8 PM between Orangeville and Kitchener, tracking into parts of the Greater Toronto Area.
This is a concern because the environment at this time may be stronger than anything we’ve seen earlier in the day. While storm development is more questionable, if it does happen, these storms could certainly pose a tornado threat.
The severe threat will continue into Eastern Ontario during the evening hours as the second round of storms moves into the area. At this point, it will likely be mainly a wind risk, however, an isolated tornado can’t be ruled out—even after sunset. The storm risk should diminish by midnight as the line of storms moves into Quebec.
