A rare weather phenomenon strikes southern Ontario again

Thundersnow has struck southern Ontario for a second time this month.

The weather phenomenon takes place when lightning and thunder strike during a snowfall.

CTV News Toronto Weather Anchor Lyndsay Morrison said thunder and lightning has been reported during a sudden snowfall on Wednesday afternoon around downtown Toronto, Burlington, Hamilton, on the QEW toward Niagara, in the Kawarthas, and near Woodstock.

“While thundersnow feels uncommon, it’s certainly not unheard of,” Morrison said.

“What’s unique about this season is that we’ve had two thundersnow events this March where it has happened in the most populated part of our country, so there have been lots of people witnessing it, recording it and reporting it!”

According to the Farmer's Almanac, thunderstorms occur when an air mass becomes so unstable that it overturns violently, usually when drastically different temperatures meet.

Local residents were quick to chronicle the “fast and furious” arrival of the spring snow, paired with a crack of thunder and lightning.

Thundersnow last struck southern Ontario less than a month ago as a major snowstorm hammered the region on March 3.

This time around, on Wednesday, a sharp cold front rushed through Toronto, bringing a “burst of heavy wet snow” after a sunny morning that began to resemble typical spring weather.

Environment Canada issued a weather advisory in Toronto for Wednesday, forecasting one to two centimetres of snow, paired with winds gusting up to 70 km/h. 

With files from CTV News Toronto's Abby O'Brien