Questionable Severe Thunderstorm Risk Through Eastern & Northeastern Ontario for Saturday Afternoon/Evening

Mother Nature has certainly cranked up the thermostat across Southern Ontario with a multi-day heatwave expected to continue into the early part of the week. Many areas will see daytime highs exceed 30°C including during the day on Saturday and for several days to come. This hotter weather is also a key ingredient in thunderstorms that could develop over the next few days bringing with it the threat of some severe weather.

The thunderstorm risk for Saturday is focused on parts of Southern Quebec and also extends into Northeastern and Eastern Ontario along the Quebec border. Any storms that develop in this area mainly during the late afternoon and early evening hours have the potential to quickly become severe with damaging wind gusts and large hail as the main threat. However, it’s not guaranteed and is dependent on storms actually developing which some models suggest the storms will stay over Quebec and not cross the border into Ontario. There is also a very low tornado threat, but it can’t be completely ruled out especially in this environment.

With the season’s first robust severe risk we thought it would be a good time to introduce our new regional thundercast timeline graphic that should help break down the risk by time instead of by location. Keep in mind this is still in testing and we’ll be tweaking it throughout the season - storms may happen outside of the timeline shown on the graphic, but it’s our best guess on when storms will develop based on the environment and future radar.

Today’s severe risk will likely occur during the late afternoon and early evening hours with a slightly earlier timeline through Northeastern Ontario compared to Eastern Ontario. The strongest threat will be found during the dinner hour between 5-10 PM depending on your location. Again, these storms could develop further to the north and stay over Quebec so it’s possible this whole event may ‘bust’.

As usual, we’ll be here keeping you updated on any active weather that may develop. Stay safe!