So, we have already examined Umester clouds and the Kelvin-Helmholtz Instability, as well as what Morning Gloria means.
However, one of the rarest types of clouds is a lenticular cloud - a cloud of regular lenticular shape, which resembles the notorious "flying saucer". An interesting detail - the lenticular clouds hardly move, no matter how strong the wind is.
A stream of air sweeping over the earth's surface flows around obstacles, and air waves are formed. Clouds usually hover on the leeward side of mountain ranges, behind ridges and individual peaks at an altitude of two to fifteen kilometers.
Promotional video:
And here we expose the pyramidal clouds.