Nube Lenticular

Did some cloud watching today. Clouds here are not an everyday occurrence, when they do appear they are usually quite plain, but on rare occasions you get some really weird and funky formations. These ones are Lenticular clouds and have been mistaken for UFOs (or "visual cover" for UFOs) because these clouds have a characteristic lens appearance and smooth saucer-like shape. Cool.

Factoid: Lenticular clouds, technically known as altocumulus standing lenticularis, are stationary lens-shaped clouds that form at high altitudes, normally aligned at right-angles to the wind direction.
Where stable moist air flows over a mountain or a range of mountains, a series of large-scale standing waves may form on the downwind side. Lenticular clouds sometimes form at the crests of these waves. Under certain conditions, long strings of lenticular clouds can form, creating a formation known as a wave cloud. Lenticular clouds are frequently observed over the Sierra Nevada mountain range.