Thundersnow brought bright flash, loud boom to Toronto: meteorologist

A large lightening strike can be seen during a Feb. 28 thundersnow event in Toronto. The image was captured from a doorbell camera in Leaside. (Supplied)

A sudden bright flash of light followed by a loud boom on Friday night is the result of thundersnow, says a meteorologist with Environment Canada.

The rare weather phenomenon, which occurred just after 8 p.m., happens when lightning and thunder strike during a snowfall.

Speaking with CP24.com Saturday, Christina Kretchman, of the national weather agency, explained that a low-pressure system was travelling across much of the province yesterday and when it passed by Toronto last night, there was quick change in airmass that caused “atmospheric instability,” resulting in a strong lightning strike followed by a loud thunder boom.

This clash of air masses with contrasting temperatures occurred as air was rising quickly, she said, adding that at the time snow pellets were falling at Toronto Pearson Airport.

Kretchman said the origin point for this uncommon weather event was somewhere in the vicinity of Sunnybrook Health Sciences Centre, near Bayview and Lawrence avenues in East York.

“It was the right time and the right place and the right ingredients to cause that to happen,” she said.

Many people have since taken to social media to ask if anyone else saw unusually bright, massive lightning strike followed by a significant clap of thunder, which some described as sounding like an explosion or a bomb.

Some of those who posted wondered if what happened was a meteor entering the atmosphere.