Lauren Mitchell posted this photo so-called “fallstreak cloud” or “hole punch cloud,” formally known as a cavum, that appeared over Chilliwack on Dec. 9, 2019. (Facebook)

Lauren Mitchell posted this photo so-called “fallstreak cloud” or “hole punch cloud,” formally known as a cavum, that appeared over Chilliwack on Dec. 9, 2019. (Facebook)

Bizarre ‘hole punch cloud’ forms over Fraser Valley

Several people posted images of the odd formation, which is scientifically known as a cavum

No, it wasn’t aliens.

Several people posted photos of a bizarre cloud formation over Chilliwack on Monday. What appeared as a giant hole in a flat, thin cloud is what’s known as a “fallstreak cloud” or “hole punch cloud.”

(See below for more photos.)

But the formal name of the cloud formation, which was added to the 2017 version of the International Cloud Atlas is a “cavum,” according to an article on The Weather Network from that year.

“This supplemental feature is caused when ice crystals are introduced into a thin cloud comprised of super-cooled water droplets, usually due to an aircraft passing through the cloud on takeoff or landing,” according to meteorologist and science writer Scott Sutherland. “With the sudden appearance of the ice crystals, the water droplets in the vicinity all rush in – creating a clear spot in the cloud – where they freeze and grow the crystals into snowflakes, which then fall out of the sky.”

The cloud also included a wispy feature below it, almost appearing like a tornado, which is a shaft of precipitation produced by the falling snow.

A similar cavum was seen over Abbotsford earlier this year prompting social media posts.

• READ MORE: Strange cloud forms over B.C.’s South Coast

People posted images of the one on Dec. 9 over Chilliwack from as far east as Bridal Falls and as far west as Langley.


@PeeJayAitch
paul.henderson@theprogress.com

Like us on Facebook and follow us on Twitter.

Get local stories you won't find anywhere else right to your inbox.
Sign up here

 

Mike George posted this photo on Dec. 9, 2019. (Facebook)

Mike George posted this photo on Dec. 9, 2019. (Facebook)

Melissa Violet Anderson posted this image of the “hole punch cloud” that appeared over Chilliwack on Dec. 9, 2019. (Facebook)

Melissa Violet Anderson posted this image of the “hole punch cloud” that appeared over Chilliwack on Dec. 9, 2019. (Facebook)

Bizarre ‘hole punch cloud’ forms over Fraser Valley

Just Posted

Langley Township Civic Facility. (Langley Advance Times files)
Housing, RCMP, Fort roads all discussed at Langley Township budget meeting

A Monday meeting touched on priorities for this year and beyond

Table for sale took a bit more work than first thought. (Mariana Aramburu/Special to The Star)
Ryan’s Regards: Clearing the clutter

Most New Year’s resolutions are abandoned by this point in the year

Submit letters to the editor through our website, via email or in writing.
LETTER: Cloverdale man said public pressure only convinces church goers they are right

Engageing churches in discussions on how to reduce transmission would be more effective than bans

When the pandemic forced the shut down of playgrounds in Langley this past Spring it sparked creativity for these Langley grandparents Herb and Cherri Kwan, who found themselves picking up a paint brush to help keep the local kids occupied. (Bernadette Amiscaray/Special to Langley Advance Times)
PHOTOS: Pandemic park closures spark artistic rock creations for retired Langley grandparents

Herb and Cherri Kwan started hiding painted rocks in Routley Park when playground closed

Shortreed Community Elementary. (Langley School District/Special to the Aldergrove Star)
Parent Advisory Council raises concerns over Langley school district power outage response

Fifteen teachers at Shortreed Community School in Aldergrove staged a sit-in strike last Wednesday

Provincial health officer Dr. Bonnie Henry prepares a daily update on the coronavirus pandemic, April 21, 2020. (B.C. Government)
B.C. adjusts COVID-19 vaccine rollout for delivery slowdown

Daily cases decline over weekend, 31 more deaths

A female prisoner sent Langford police officers a thank-you card after she spent days in their custody. (Twitter/West Shore RCMP)
Woman gives Victoria-area jail 4.5-star review in handwritten card to police after arrest

‘We don’t often get thank you cards from people who stay with us, but this was sure nice to see’: RCMP

Cannabis bought in British Columbia (Ashley Wadhwani/Black Press Media)
Is it time to start thinking about greener ways to package cannabis?

Packaging suppliers are still figuring eco-friendly and affordable packaging options that fit the mandates of Cannabis Regulations

An elk got his antlers caught up in a zip line in Youbou over the weekend. (Conservation Officer Service Photo)
Elk rescued from zip line in Youbou on Vancouver Island

Officials urge people to manage items on their property that can hurt animals

A Trail man has a lucky tin for a keepsake after it saved him from a stabbing last week. File photo
Small tin in Kootenay man’s jacket pocket saved him from stabbing: RCMP

The man was uninjured thanks to a tin in his jacket

Tla-o-qui-aht First Nation Chantel Moore, 26, was fatally shot by a police officer during a wellness check in the early morning of June 4, 2020, in Edmundston, N.B. (Facebook)
Frustrated family denied access to B.C. Indigenous woman’s police shooting report

Independent investigation into B.C. woman’s fatal shooting in New Brunswick filed to Crown

Delta Police Constable Jason Martens and Dezi, a nine-year-old German Shepherd that recently retired after 10 years with Delta Police. (Photo submitted)
Dezi, a Delta police dog, retires on a high note after decade of service

Nine-year-old German Shepherd now fights over toys instead of chasing down bad guys

Nurses collect samples from a patient in a COVID suspect room in the COVID-19 intensive care unit at St. Paul’s hospital in downtown Vancouver, Tuesday, April 21, 2020. (THE CANADIAN PRESS/Jonathan Hayward)
5 British Columbians under 20 years old battled COVID-19 in ICU in recent weeks

Overall hospitalizations have fallen but young people battling the virus in hospital has increased

Most Read