We are currently tracking the risk of some severe thunderstorms across much of Southern Ontario including the risk for some non-severe storms in Central and Eastern Ontario extending into Northern Ontario.
Widespread showers and thunderstorms are expected to cross into the Extreme South and continue to strengthen and develop over the region. The main threats will include wind gusts between 100-110km/h or higher as well as hail towards 1.5 to 2cm in size. Multiple storms passing over the same region could produce flash flooding with rainfall totals between 50-125mm in a short period of time. For the high confidence and severity, we have highlighted this region as moderate/yellow/'3'.
Towards the north into the Simcoe/GTA/Muskoka region, thunderstorms, some severe, may 'pop-up' across the region. A few of these isolated developing thunderstorms may be capable of producing a tornado and hail towards 2.5 or possibly even 3cm in size. We have highlighted this region as low/green/'2'.
Into Eastern Ontario, a few weakening thunderstorms over Lake Ontario may briefly strengthen into an isolated severe storm over Prince Edward County as they extend towards Kingston and Belleville. We have highlighted this region as low/green/'2'.
In the 'mainly non-severe risk', we can't rule out a very isolated severe thunderstorms, especially from Huntsville and Haliburton over to Renfrew and Ottawa. We have highlighted this region as mainly non-severe/blue/'1'.
The best parameters will extend in the Extreme South and along the Dundalk Highlands into the Shelburne and Orangeville regions for hail and an isolated tornado, the biggest wind threat is in the Extreme South and the flooding threat from training storms is possible across most of the region.