The Canadian city of Toronto has been left reeling after experiencing one of the most severe thunderstorms in its history.

The storm began to develop during Monday afternoon, 19GMT, in hot and humid conditions. Within two hours a supercell had engulfed the city. There were huge variations in recorded rainfall across greater Toronto.

The largest total was 126mm at Pearson International airport. Downtown Toronto was deluged with 90mm while Butterville airport, just 40km to the north, picked up a mere 17mm.

Although the city has experienced a wetter spell – Hurricane Hazel deposited a staggering 121mm in October 1954 – this was an exceptional storm.

It smashed the previous one-day rainfall record of 36mm of 2008. The average rainfall total for the whole month of July is just 74mm.

“[This was] one of the wettest moments in Toronto’s history,” said Environment Canada senior climatologist Dave Phillips

The effects of all that rain were widespread and severe. The train network was stopped due to power and signalling issues and several stations were flooded.

A ten-car, double-decker commuter train with around 1,000 passengers on board became stuck for several hours. Police and firefighters used boats to rescue exhausted passengers who had been forced to flee the flooded lower decks of the train.

Electricity supplies to many homes were also interrupted. Up to one million homes lost power within the city and surrounding suburbs but, for most consumers, outages were short-lived.

Scores of cars were abandoned in the flooded streets and many flights were cancelled from the downtown Billy Bishop airport because of a loss of power in the terminal building.

The forecast is for the potential of further thunderstorms through Tuesday and Wednesday before slightly cooler, fresher weather returns later in the week.

Source: Al Jazeera