Unnerved sky-watchers from Wyoming, USA snapped photos showing a rare cloud formation that crashed across the horizon looking like ocean surf.
Rachel Gordon, a local Rachel Gordon said that “This was something special” and she knew right away she had to capture it.
On Tuesday, the billowy phenomenon could be seen above the Bighorn Mountains from Sheridan.
They are also known as Kelvin-Helmholtz instability. These occur when an air stream moves faster than the rising air below.
Ms Gordon told BBC News that she took the photos from her parents’ back door and posted them to Wyoming through The Lens.
“I just want others to enjoy this experience.”
BBC Weather’s Matt Taylor said that the images are among the most spectacular and dramatic examples of Kelvin Helmholtz clouds that he has ever seen.
He said, “Part of the beauty in Kelvin-Helmholtz cloud is that they really reflect the fluidity of atmosphere.”
“How, just like waves in an ocean, the atmosphere responds to its environment. The air is actually rising up and falling over itself.”
Named after Lord Kelvin and Hermann von Helmholtz scientists, the cloud formation was created. They studied the physics that led to the phenomenon.
These formations are referred to by the UK-based Cloud Appreciation society as the crown jewel of many cloud spotters’ collections.
They are also known as fluctus cloud and were a possible inspiration to Van Gogh’s painting Starry Night.
