Many people in the US state of Wyoming were shocked when they looked up to the sky and saw a strange but beautiful cloud formation that looked like ocean waves.
As if the waves of the sea crashed against the firmament.
“It was very special and I immediately knew that I needed to capture it,” explained Rachel Gordon, one of the people who managed to capture the formation and post it on her social networks.
The undulating phenomenon was visible on Tuesday over the crest of the Bighorn Mountains from the city of Sheridan, located 520 km. in northern Cheyenne, the state capital.
These formations, known as Kelvin-Helmholtz instability , form when a faster air current moves above the air below.
Gordon, who told the BBC that he took the images from the back door of his parents’ house before posting them on the Facebook page, noted: “It was an awesome moment.
“I’m glad that others can also enjoy the experience now,” he added.
BBC Weather’s Matt Taylor notes that the images are one of the most impressive examples of Kelvin-Helmholtz clouds he has ever seen.
“Part of the beauty of Kelvin-Helmholtz clouds is that they really show the fluidity of the atmosphere ,” he said.
“Like waves in the ocean, the atmosphere moves and responds to the environment around it. The air effectively rises and falls on itself.”
The cloud formation is named after the scientists Lord Kelvin and Hermann von Helmholtz, who studied the physics behind the phenomenon.
The UK-based Cloud Appreciation Society describes these formations as the crown jewel in the collections of many cloud watchers.
Also known as fluctus clouds, they are considered a possible inspiration for Van Gogh’s Starry Night painting.