Flash flooding sweeps across southern Ontario

Close to 100mm of rain falling in just a few hours flooded large sections of the GTA Tuesday morning, including the Don Valley Parkway shown above. (Twitter Photo #ocstorm)

Just as it did last week in Montreal, severe thunderstorms produced widespread flash flooding across the greater Toronto region on Tuesday.

A cluster of thunderstorms developed along the Lake Ontario shoreline on Tuesday morning, hammering southern Ontario with rounds of heavy rain. Significant flash flooding occurred across the GTA, closing roads and inundating homes, businesses and even Union Station with deep water. 

Public transportation in several areas ground to a halt after 97.8mm of rain fell at Toronto's Pearson Airport, the fifth wettest day on record at that location. Most of that in just a few hours. TTC stations filled with water, and firefighters had to rescue commuters from Go Trains. A dozen motorists were also rescued from the badly flooded Don Valley Parkway. Toronto Hydro reported as many as 170,000 customers without power at the height of the storm. Many roads and ramps remained closed into Wednesday morning as the cleanup continued. It was Toronto's third "100-year flood" since 2013.

Damage will likely run into the tens of millions after major, widespread flooding occurred across the Toronto region on Tuesday, July 16. (Photo: OPP)

Significant flooding was also reported in the London region. The line of thunderstorms swept northeast towards Kingston before moving east into upstate New York and passing well south of Montréal. Severe weather was reported in New York and Vermont, with wind damage, power outages and more flooding.

Despite the hot and humid weather across southern Quebec, most of the storms were tame in nature, with lots of lightning, but just a few millimetres of rain here in the St. Lawrence Valley late Monday night and again Tuesday afternoon.

With the amount of cars badly flooded and likely destroyed as well as the amount of water that flowed into homes, train stations and businesses, damage will run into the tens of millions of dollars, just as it did here in Montréal last week.