Beautiful, long-lasting lenticular clouds formed over the mountains of Flagstaff, Ariz., on Thursday afternoon and persisted until sunset. The clouds were captured in a timelapse video by the National Weather Service.
I’m happy to report that they were neither spaceships nor pancakes, but lenticular clouds, or altocumulus standing lenticularis, which is Latin for “lens-shaped.”Lenticular clouds form in stable environments with strong winds aloft, where moist but stable air flows over a mountain creating standing gravity waves on the downwind (or lee) side. Generally, the mountain range must be oriented perpendicular to the prevailing winds in order for this clouds to form. If the air temperature cools enough to condense the water vapor in it, a lenticular cloud may appear.
If you watch closely in the video above, you can also see the morning weather balloon launch around the 2-second mark.
More cool clouds: