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 Chilliwack

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

 

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

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

Just Posted

Fabrication work for Vedder Bridge roundabout art project is well underway

Funds of $255K held in reserve from new bridge budget do not represent a new cost for artwork

Chilliwack school trustees using Zoom to conduct meetings during pandemic

Public participation not available, but staff taking public questions before and after meetings

A little snow and hail for Chilliwack but no record broken

It was the second snowiest April day in Chilliwack on record Friday

B.C. firefighters only responding to most life-threatening calls during COVID-19 pandemic

The directive comes after province spoke with paramedics, fire services, according to top doctor

Are you a senior needing help during COVID-19? These Chilliwack volunteers are here for you

Picking up groceries and phone chats are just some of the services being offered at no charge

As 240K apply for emergency benefit, Trudeau says aid coming for Canadians left behind

Canada Emergency Response Benefit provides $2,000 per month

B.C. clears more acute hospital beds as COVID-19 case growth slows

Province holding about 40% of beds empty for peak still to come

UPDATE: UK PM Boris Johnson moved to intensive care after COVID-19 symptoms worse

He has been quarantined in his Downing St. residence since being diagnosed with COVID-19 on March 26

Travellers, travel agents ‘in agony’ over refund policies and customer service

Many Canadian carriers are offering customers flights rebookings or travel vouchers — but not refunds

Introverted and extroverted kids likely to react differently to COVID-19 restrictions

B.C. child psychologist says your parenting approach can’t be one-size fits all in social isolation

B.C. begins taking submissions for $2M COVID-19 research fund

Rural health, impact of shifting hospital resources among priorities

Wearing non-medical masks can stop spread of COVID-19 before symptoms start: Tam

Health officials had previously not recommended wearing them

Easter Bunny not a COVID-19 carrier, allowed to do drop offs

World Health Organization grants permission to Bunny as he cannot transfer the virus

Most Read