NORFOLK, England — A rare wave-shaped cloud formation has been captured over the skies of England.
Joy Patrick noticed what is known as a Kelvin-Helmholtz cloud hovering in the sky above Trimingham, Norfolk on the evening of July 23, 2023.
“Kelvin-Helmholtz is one of the rarest cloud types, occurring when two different layers of air are moving at different speeds,” said the Met Office.
This causes winds to blow faster at the upper level than at the lower levels.
The result is the appearance of a repeating breaking wave pattern, formed similarly to the waves over the sea, which are created when the wind blows faster than the water moves.
“A Kelvin-Helmholtz instability forms where there’s a velocity difference across the interface between two fluids: for example, wind blowing over water,” said Earthsky.
“The Kelvin-Helmholtz clouds occur when two different layers of air in our atmosphere are moving at different speeds (a phenomenon known as shear). When the upper layer of air is moving at a higher speed than the lower-level air, it may scoop the top of an existing cloud layer into these wave-like rolling shapes,” said the Met Office.
Joy was lucky enough to capture the event from her window in Norfolk.
“It really was fleeting. I was walking into my bedroom to close the windows and curtains and saw the cloud,” said Joy.
“I took the photo, then went into the bedroom and when I came out it had totally disappeared.
“It was magical, I feel very privileged to have witnessed it,” said Joy.
According to the Met Office, the clouds are more likely to occur on windy days. They are often good indicators of aircraft turbulence.Kelvin Helmholtz instability is a scientific phenomenon not exclusively associated with clouds. It can occur wherever there is a velocity difference across the interface between two fluids. The most obvious example is wind blowing over water, in which fast-moving air can create the waves on the slower-moving water.
Produced in association with SWNS Talker
Edited by Judy J. Rotich and Newsdesk Manager