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