The Guelph Mercury reports:
It is official: the epic rainfall in Toronto on Monday afternoon that drenched highways, had cars bobbing up and down in rainwater and overwhelmed 911 was an extreme weather event.
No, experts say, it wasn’t because of climate change. But yes, we will likely see more storms like it.
“This is likely the wettest moment in Toronto’s history,” David Phillips, senior climatologist with Environment Canada, said on Monday evening while rain was still falling. “By the end, we may have a new all-time one-day record.”
More than 90 millimetres of rainfall was recorded at Pearson International Airport in just two hours, starting at about 4:30 p.m.
To put it in perspective, the wettest day in Toronto was Oct. 15, 1954, when Hurricane Hazel slammed the city and 121.4 millimetres of rainfall was recorded over the entire day.
The wettest July day in the city was July 28, 1980, when 118.5 millimetres of rain fell — again, over the entire day.
July usually gets about 75 millimetres of rain in the entire month.
That’s why Monday’s rainfall was epic.
“All of that rain, it fell in less than two hours,” Phillips said. “It’s just incredible.”
Brian Edwards, a meteorologist with forecasting service Accuweather.com, said a cluster of extremely slow-moving thunderstorms was responsible for the deluge.
“It was almost as if the system refused to move . . . it stood there and rained and rained,” he said. “Nobody could have guessed at the amount of rain it would unleash.”
Flooding was inevitable, Edwards said, adding that no infrastructure can possibly handle that kind of rain.
But Phillips points out that Toronto, like other cities, is becoming more vulnerable to flooding as more of it is covered with asphalt. Building materials are impervious to rain and so “we end up with flash floods,” he said.
Making things worse, the ground had still not absorbed all the water from earlier storms by the time the big downpour hit, so there was nowhere for the rainwater to escape.