Lenticular
Photos of lenticular clouds at Mt. Shasta, CA.
Lenticular clouds are unique clouds which typically form around hills and mountains, as a result of the way that the air moves. These clouds look quite distinctive, like giant flying saucers or something like lopsided stacks of pancakes. Many famous mountains around the world are often photographed with a cap of lenticular clouds, including Mount Shasta and Mount Fuji.
