Rare wave clouds in Wyoming shock netizens

Skywatchers in the American state of Wyoming were astounded as they captured images of a rare cloud formation that was slamming across the horizon like ocean waves.

"This was special and I immediately knew I needed to capture it," said local Rachel Gordon, who shared the image on social media.

On Tuesday, the city of Sheridan could see the wavy phenomena above the top of the Bighorn Mountains.

The phenomenon is called Kelvin-Helmholtz instability. It occurs when there is a difference in velocity between two layers of a fluid, such as air or water. 

This difference in velocity can cause the layers to become unstable and mix, resulting in the formation of waves on the interface between the two layers. 

The Kelvin-Helmholtz instability is named after Lord Kelvin and Hermann von Helmholtz, who independently described the phenomenon in the 19th century.

Gordon told BBC News that she captured the photos from her parents' back door. Her images are now all over the internet.

"I'm just glad others can enjoy the experience now, too," the outlet quoted her as saying.

BBC Weather's Matt Taylor said that Kelvin-Helmholtz clouds are particularly beautiful because they vividly display the mobility of the atmosphere.

He added that the atmosphere moves and reacts to its surroundings, much like ocean waves do.