Toronto just saw record rainfall. Why weren't people ready?

Storm chasers saw it coming, and Environment Canada's rainfall warning suggested a deluge was coming — so why were so many people caught off guard by the powerful storm that hit Toronto on Tuesday?

And how are residents supposed to prepare for events like this?

David Phillips, senior climatologist with Environment Canada, says the expected rainfall amounts were there all along.

"It was a surprise in terms of the [fact] it was well forecasted and the amounts were there in the forecast. But when you actually see them falling in a city as huge as Toronto, it becomes really devastating," Phillips said in an interview with CBC News Network on Tuesday.

The record rainfall caused widespread power outages and shut down several major traffic routes. At the height of the storm almost 100 millimetres of rain fell in some areas, Environment Canada says, surpassing the city's daily record set back in 1941.

Some 97.8 millimetres of rain fell at Pearson International Airport, while 83.6 millimetres fell on Toronto's downtown core in just a few hours. About 87 millimetres was recorded at Billy Bishop airport on Toronto's waterfront, according to preliminary figures from the federal department.

City manager Paul Johnson said the city will review what happened Tuesday to be better prepared in future.

"I don't want people to feel we were unprepared. We were," Johnson said at a news conference Wednesday.

"However, the situation changed significantly and when that shifted, we needed to pivot to try and ensure the safety of the folks that were caught in the storm."

Johnson said the city has been fielding questions about its decisions in responding to the powerful storm, particularly  when it comes to roadways.

"We always review every incident after, and we will be paying particular attention to how we can utilize data and evidence in a stronger way to look at what response we should take," he said.

A series of separate storms consecutively drenched the GTA, but particularly the city of Toronto. He said the system that brought the rainfall was "unique" from a meteorological perspective, Phillips said.

"There was a line of storms from London to the west part of Toronto that lined up like a parade, like jumbo jets on the airport tarmac. And there was storm on top of storm coming in one after the other, dropping their load of precipitation," he said Tuesday.

A rainfall warning was issued for the city on Tuesday morning, with a risk of thunderstorms continuing in the afternoon and evening. The rain fell on Toronto in a four-hour window, but major traffic and transit disruptions persisted in the aftermath.