The heavens open: Rare hole-punch clouds cause spectacle in the sky over Washington and British Columbia

• e-mail

A strange cloud formation has left residents in Washington State and British Columbia perplexed, after showing up in the sky several times this month.

Experts say the stunning clouds that look like a brushstroke are known as hole-punch clouds or fallstreak holes, and are caused by a rare - but rather ordinary - atmospheric occurrence.

Residents in Lower Mainland, BC witnessed a fallstreak cloud over their town early Sunday, and it happened again over Vernon, BC the following morning.

Scroll down for video 

Stunning: A resident in Spokane, Washington captured this jaw-dropping picture of a fallstreak cloud that appeared in the sky the morning of February 18

Fallstreaks were also seen above Spokane, Washington earlier last week.

These unfamiliar clouds form when temperatures are below freezing, but water droplets in the clouds have yet to freeze due to a lack of ice particles. 

When ice particles form quickly, it causes a domino effect as the water droplets connect with the crystals, which get heavier and then start to fall all of a sudden - leaving a large hole in the cloud.

The wispy clouds that form in the center of the hole are the water particles falling. 

Passing airplanes are thought to be the reason behind the formation of these clouds, since a drop in pressure caused by their wings or propeller tips cools the air quickly. 

Rainbows are sometimes seen with fallstreak clouds, thanks to light refracting off the water droplets.  

Unusual: The rare cloud formations have been appearing more frequently above Washington and British Columbia this past month. The above picture and following three images were taken by Zora Fernandez, from the Sheraton Guilford Hotel in Surrey, BC around 6:30am on February 22

Like a brushstroke: Fallstreak holes are created by a rare atmospheric occurrence sometimes sparked by passing airplanes. Another picture taken by Zora Fernandez in Surrey, BC Sunday morning 

Phenomenon: The formations occur when ice particles are rapidly introduced into a cloud and water droplets start to fall suddenly, causing a hole in the cloud, and a few wisps where the condensation is happening. Another picture taken by Zora Fernandez in Surrey, BC Sunday morning

Beautiful colors: Rainbows are sometimes seen with fallstreak clouds, thanks to light refracting off the water droplets. Another picture taken by Zora Fernandez in Surrey, BC Sunday morning