“Extremely Great” Clouds Appear in Southern Ontario | News

People in London, Ont. Surrounding communities including Cambridge, Kitchener, Waterloo, Guelph, Fergus, New Hamburg, Stratford and Brantford saw some unusual wave-like clouds around noon on Wednesday, February 7, and people were reacting on social media.

“Some of the coolest clouds over London right now,” wrote one person who shared a series of photos on the Ontario Storm Reports Facebook page, run by Instant Weather Ontario.

Soon, other people were sharing their photos and commenting.

“I've been on this earth for 50 years and I've never seen clouds like this,” wrote another commenter.

“Angel wings,” wrote another.

“Wow, so cool,” wrote another.

One person in the comments said, “Wow, those are really interesting clouds, what are they called or how did they form?” He asked a question.

What are Kelvin-Helmholtz clouds?

Alanna Franks, a meteorologist at Instant Weather, explained the sighting as a rare Kelvin-Helmholtz cloud in Ontario. Tidal clouds are formed when the wind above the cloud moves much faster than the wind below it.

“It's not something that happens very often because you need favorable conditions, a big difference in air speed from top to bottom,” he said.

“We call this vertical or sheer velocity … The top of the cloud rises like a wave. So you get a wave-like pattern.”

Kelvin-Helmholtz clouds usually form in mountainous areas because higher winds can blow unimpeded, and lower winds are much slower because the mountains act as a barrier, so these types of clouds are not often seen in Ontario.

“I've never seen this before. That's something that doesn't happen very often here,” Franks said. “I'm very jealous.”

These clouds also don't last long and fly away quickly, he said.