Supercells
Fortunately aja phenomenon this one including a unique phenomenon that rarely happens. Supercells, in addition to their scary form, are also the most dangerous types of storms. Sometimes he appears in the form of a vortex, like a plate, or a large roll in the sky.
This storm is most common in the central United States and is often mistaken for UFO sightings when it appears in the form of a large disk.