Unbelievable supercell storm cloud over neighborhood. Photo by: Pat Kavanagh

Mammatus clouds over Quebec, Canada. Mammatus, also known as mammatocumulus, is a meteorological term applied to a cellular pattern of pouches hanging underneath the base of a cloud. Photo by: Michel Filion

Purple sky during thunderstorm over Nebraska. Photo by: Anne Goforth

Lenticular clouds over Hawaii. A stationary lens-shaped clouds that form in the troposphere, normally in perpendicular alignment to the wind. Photo by: Jolly Sailor

Beautiful red clouds over long reef, Australia. Photo by: Glenn Crouch

Strange shape of asperatus clouds over New Zealand. The clouds are most closely related to undulatus clouds. Although they appear dark and storm-like, they tend to dissipate without a storm forming. Photo by: Witta Priester

Incredible supercell thunderstorm, Montana. Photo by: Antony Spencer

Stunning view on clouds from top of the mountain. Photo by: Adam Gibbs

Magnificent sky over Czech Republic captured using long exposure technique photography. Photo by: Martin Rak

Above the clouds, seen from airplane above Switzerland. Photo by: Edgar Moskopp

Time stacking photo of red clouds. Photo by: Matt Molloy

Aurora Borealis behind clouds, Iceland. Photo by: Friðþjófur M