Thunderstorms, rain looming for Toronto as heat warnings hit southern Ontario

Parts of southwestern Ontario are under a tornado watch, with Environment Canada as a severe thunderstorm moves its way across the province.

An orange tornado watch has been put in place for several counties in southwestern Ontario shortly before 5 p.m., but more cities have been placed under watches as of 6:15 p.m.

Environment Canada says conditions within the region are favourable for this thunderstorm to potentially produce tornadoes, as well as strong winds that could exceed 110 km/h.

Quarter to loonie sized hail and torrential downpours are also expected from the storm.

“Significant damage or destruction to infrastructure, homes and the natural environment is possible,” Environment Canada said in a bulletin.

If a tornado warning is issued or a tornado occurs, people are urged to go indoors to a room on the lowest floor away from outside walls and windows. This could include a basement, bathroom, stairwell or interior closet.

People should leave mobile homes, vehicles, tents, trailers and other free-standing shelters and move to a strong building if you can.

As a last resort, the weather agency says you can lay in a low spot and protect your head from flying debris.

Red tornado warnings were briefly issued for Kitchener-Cambridge-Region of Waterloo and Listowel-Milverton-Northern Perth County at about 5:16 p.m., but they have since been dropped.

Those regions remain under red severe thunderstorm warnings.

Stratford-Mitchell-Southern Perth County and Woodstock-Tillsonburg-Oxford County also briefly were upgraded to red tornado warnings, but have since returned to being under orange tornado watches.

The tornado watch comes as showers and thunderstorms also continue to move through other parts of southern Ontario, including Toronto, amid high heat.

At about 5:08 p.m., an emergency alert was issued in the Greater Toronto Area warning of destructive winds and very large hail.

Environment Canada also upgraded its severe thunderstorm watch to a red severe thunderstorm warning for the City of Toronto.

Red severe thunderstorm warnings have also been issued for Hamilton, Brantford, Caledon, Kitchener and Mississauga.

The agency also issued a yellow heat warning for several regions earlier in the day, including Niagara Falls, that indicates maximum temperatures of 30 to 32 C on Wednesday. Humidity will make it feel near 40 degrees.

The federal weather agency also said the heat event may continue into Thursday for Windsor and Essex County, but confidence is low.

Niagara will also see a 60 per cent chance of showers and a risk of a thunderstorm with wind gusts hitting 40 kilometres per hour in the afternoon. Showers with thunderstorms will begin in the evening and end after midnight.

The precipitation is part of a system blanketing much of the region Wednesday, with Toronto in for 20 to 30 millimetres of rain in some parts by the afternoon.

A first wave of thunderstorms passed through the area in the morning, but a second wave in the evening is expected to bring another 15 to 25 millimetres of rain.

The Toronto and Region Conservation Authority (TRCA) said on its website that there’s a higher potential for flooding in its river systems. It also warned that its watersheds have already gotten between eight and 55 millimetres of rain on Monday.

“The ground is saturated which will limit the ability to absorb more rainfall,” the TRCA said.

“Heavy rain from thunderstorms could cause flooding in flood plains and low-lying areas that do not drain well, especially if significant amounts of rainfall is received.”

The weather system is anticipated to pass over the region early Thursday morning, after which a mix of sun and cloud is forecast for several days in Toronto.