A videograb shows mammatus clouds forming over Hebei province in China.

Syed Shayaan Bakht, Gulf Today

A video of mammatus clouds forming over a Chinese province recently is doing the rounds on social media.

The spectacular moments of the rare mammatus clouds were captured in Hebei province.

The clouds are shaped like cotton balls making it look surreal.

Local media reported that the unusual fluffy balls of clouds covered the skies over Hebei province during stormy weather.

It is believed the rare phenomenon was recorded on July 31.

Mammatus are sagging, pouch-like lumps on the undersides of clouds that usually happens after thunderstorms.

So the question arises, how do these cloud bottoms appear like bubbles?

In normal circumstances, cloud bottoms are usually flat.

But because the warm and humid air rises and cools, it condenses into droplets of a certain temperature, which usually happens at a very specific height.

As the water droplets grow, opaque clouds are formed. However, under certain conditions, cloud pockets containing large water droplets or ice droplets are formed, causing parts of the cloud to sink, thus creating the signature cotton ball-like appearance.

During storms, such air pockets may appear in the turbulent air. When exposed to the sun from the side, the resulting Mammatus clouds have a spectacular effect.