This is the view from the top of Sail looking back towards the Helvellyn range. I took the picture through my polarising sunglasses to enhance the effect. Lenticular clouds are the ones that look like flying saucers. They are the ones reported as UFOs. There was a strong wind blowing from the right of the picture. As that has to rise over the mountains, a stationary wave is formed on the other side of the mountains (the left of the picture). The peaks of the antinodes get cold enough for condensation into cloud. I suppose that the wave packet gives rise to the saucer shape.
It has just occurred to me that I can check one of these claims. If I find the photograph taken in the direction that the wind is coming from, there shouldn't be any lenticular cloud because this should form after it has been over the mountains. Here's the picture looking south over Robinson to the Scafells
Lo and behold! There are a few cumulus in the far distance. Thus far the theory holds up!
