Another stormy Wednesday for southern Ontario

Another potentially stormy Wednesday is on the horizon for southern Ontario. Heat, humidity and a frontal system will create the threat of severe storms, which may bring heavy rain, localized flooding, and strong wind gusts reaching up to 80 km/h.

After the severe flooding, damaging winds, and tornadoes across parts of Ontario last Wednesday, a storm-free week would be welcome news.

Unfortunately, that isn’t the case as an upper trough moves across the Great Lakes throughout the day on Wednesday. That means an elevated risk of thunderstorms, possibly severe, in a swath of southern Ontario, with heavy rain, gusty winds and localized flooding as the main threats.

Heat, humidity sneaks in for midweek storm threat in southern Ontario

As the Low lifts across northwestern Ontario and moves into Hudson Bay, a more muggy southerly flow will develop across the heart of Ontario.Temperatures will climb into the mid-20s by Tuesday and Wednesday, with Windsor and Sarnia making a challenge at 30 degrees.

On Wednesday, moisture values reach their peak across southern Ontario, along with the available energy to develop thunderstorms ahead of the cold front. Localized flooding remains the current hazard with this batch of storms as total moisture in the atmosphere is modelled to be between 40-60 mm--a red flag for flooding potential.

Environment Canada