This unusual cloud formation lasts only a brief period of time, which is why it is so rare to see one in the sky. Jonathan Belles of the Weather Channel calls it a “horseshoe cloud”, which is definitely an appropriate name. Belles explains that sometimes a flat, pancake-like cloud moves over a column of warm air. The warm air punches a hole through the center of the cloud, sending that water vapor higher while the edges remain condensed. Perfect conditions are necessary for one of these horseshoe clouds to form, which is why they rarely last more than 20 minutes.