What is this bumpy cloud that appeared in the United States?

Yesterday, a “punched” cloud appeared in the sky of the American state of Missouri. The image, recorded by viewers of local TV station KY3 News, was shared by the Springfield city office of the National Weather Service.

the @KY3StormTeam Send us some photos that some viewers sent in yesterday:

This is a “hole cloud”. This could be caused by aircraft passing through the cloud, causing the very cold water droplets in the cloud to suddenly evaporate or freeze and start falling.. (1/2) pic.twitter.com/zji81IWsUH

– NWS Springfield (@NWSSpringfield) December 20, 2023

But what cloud was that? Therefore, in English it is called “Hole Punch Cloud”, or in free translation, a hole or hole cloud. Hole clouds form when part of the cloud layer freezes into ice crystals and falls, creating a hole in the cloud layer.

This process is stimulated by the presence of supercooled water droplets in the cloud. Supercooled water is water that remains in a liquid state, even though it is below the freezing point.

When an airplane passes through the cloud layer, the turbulence created by its passage can cause some of the supercooled water droplets to freeze. These frozen droplets then fall from the cloud, leaving a hole behind. The surrounding droplets begin to evaporate, creating a circular or oval hole in the cloud layer.

Punch clouds usually have a well-defined circular or oval shape. They can be very large and are often visible from the ground. When they form, they eventually attract attention and photos end up on social networks dedicated to meteorology.

These burrow clouds are often associated with certain meteorological conditions, including medium to high-level clouds such as altocumulus or altocumulus. The presence of supercooled water droplets and the right temperatures is crucial for cloud formation.

Although uncommon, it is not rare and has been documented several times in the United States, where the climate is the coldest and air traffic is the busiest in the world. However, they can be observed in different parts of the world, if suitable weather conditions are present.

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