Mammatus clouds
The name “Mammatus” is derived from the Latin word for udder, due to the resemblance between the shape of these clouds and the udder of a cow. They are pouch-like cloud structures and a rare example of clouds in sinking air. Sometimes very ominous in appearance, mammatus clouds are harmless and do not mean that a tornado is about to form; a commonly held misconception. In fact, mammatus are usually seen after the worst of a thunderstorm has passed.


Lenticular Clouds
Lenticular clouds are unique clouds which typically form around hills and mountains, as a result of the way that the air moves. If the temperature at the crest of the wave drops to or below the dewpoint, moisture in the air may condense to form lenticular clouds. Many famous mountains around the world are often photographed with a cap of lenticular clouds, including Mount Shasta and Mount Fuji.

Mushroom Clouds
A mushroom cloud is a distinctive mushroom-shaped cloud of smoke, condensed water vapor, or debris resulting from a very large explosion. They are most commonly associated with nuclear explosions, but any sufficiently large blast will produce the same sort of effect.