- Rare phenomenon is bizarre cloud formation called fallstreak or hole-punch cloud
- Fallstreaks form in clouds of supercooled water droplets
- Aircraft punching through this cloud layer can cause air to expand and cool as it passes over the aircraft, creating the hole
Southern California residents were treated to a far-out sight as a rare cloud formation made for a unique daytime sky on Saturday.
The rare atmospheric phenomenon is a strange cloud formation of fallstreak, or hole-punch, clouds.
Experts say the stunning clouds that look like brushstrokes or seashells – even apt for the coastal region – are caused by a rare but rather ordinary atmospheric occurrence.
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Beauty in the ordinary: The stunning cloud formation that appeared over the Southern California sky this weekend adds another dimension to a parking lot
The rare atmospheric phenomenon that recently appeared in SoCal is a strange cloud formation, known as fallstreak, or hole-punch clouds. Pictured: Santa Monica Mountains
The view from Griffith Observatory shows the unique cloud formation over the Los Angeles Basin. These clouds form when temps in the sky are below freezing, but water droplets in the clouds have yet to freeze
These unfamiliar clouds form when temperatures in the sky 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.
The wispy clouds that form in the center of the hole are the water particles falling. Stephanie Hamilton Carr wrote that the phenomenon looked like ‘a portal or invisible mother board ship’
The clouds burst at the Women’s March: Sebastian Rivera snapped this shot of LA’s City Hall during the city’s women’s march on Saturday against Donald Trump’s political agenda
A fallstreak hole forms when part of the cloud layer forms ice crystals which are large enough to fall as a ‘fallstreak’.
They form in clouds of supercooled water droplets – water below 0°C but not yet frozen.
These water droplets need a tiny particle to freeze or to be cooled below -40 °C.
Aircraft punching through this cloud layer can cause air to expand and cool as it passes over the aircraft wings or propeller.
This change in temperature can be enough to encourage the supercooled droplets to freeze and fall from the cloud layer in this distinctive pattern.
High contrast: The cloud appears majestic against a green and brown earthen landscape and blue sky
Victoria Harrison wrote: ‘It’s the portal to the upside down world’
Dulce Castro said her five-year-old thought the clouds looked like footprints