What a stonker of a day ,beautiful weather for a change, and Nice to see a rare formation of cloud , Kelvin- Helmholtz. ....taken over the skies of Worcestershire / Gloucestershire. Formed from two gradients of wind ,speed and direction ,at different heights (wind shear) Winds to the base of the cloud far less strong ,winds to the top of the cloud far stronger ,usually as a result of the jet stream over-riding the cloud. A little bit like a strong wind over a body of water ,whipping up the top of the water and making it into peaks ,just like what you see on this photograph about 30,000 feet up in the atmosphere. Interesting that water on Earth and the atmosphere behave very similar in certain situations. ☺