Southern Ontario is bracing for another round of strong to severe thunderstorms on Wednesday, with the Greater Toronto Area, Barrie and Niagara Region in the path of storms that could bring large hail, heavy downpours and localized flooding.
According to The Weather Network, a highly moist and unstable air mass sitting over southern Ontario, combined with a moderately strong northwest airflow aloft, is expected to boost storm dynamics through the afternoon and evening hours.
Evening commute could be affected
The severe weather is forecast to begin building in the afternoon and could affect evening commutes across the Barrie area, the GTA and the Niagara Region, The Weather Network reported.
Niagara, which recently experienced devastating flooding from earlier storms, could see another 30 mm of rain from Wednesday's system. A weak supercell is also possible as the storms develop.
The storms are expected to continue through the evening and push into the London-Windsor region.
Wildfire smoke adds uncertainty
One complication forecasters are watching is upper-level smoke from wildfires. The jet stream is carrying smoke from British Columbia directly into Ontario, and that smoke could suppress thunderstorm development and severity, according to The Weather Network.
Eastern Ontario also faces an additional risk of severe storms along the Ottawa-Montreal corridor, where thunderstorm energy and instability are available but mid-level winds and moisture are weaker.
Disruptive storms, some of them severe, are expected to develop near Ottawa by late afternoon or early evening, then track east into Quebec and across the international border by the evening. The main hazards there include heavy rainfall, large hail and strong winds.
Cooldown by Friday
By Friday, a provincewide cooldown is expected to bring temperatures down to slightly below seasonal values.
Residents are advised to stay up to date on changing conditions and any weather alerts in their area.
