They look like flying saucers or marshmallows.
These UFO-looking lens-shaped clouds called lenticular clouds often develop near the peaks of mountains, as in the case of Mount Fuji in Japan.
Lenticular clouds form when strong winds force air up and over a topographic barrier such as a mountain in a wave-like pattern.
Once the rising air hits the obstructive peak, an “eddie”, and then mixes with the upper wind, the air deflects the mountain wind downward to create the lampshade-looking clouds. (Be sure to witness the strange beauty of mammatus clouds as well.)
Here’s a collection of lenticular clouds forming in different settings — over buildings, volcanoes, and grassy fields. You love to see it!