Pyrocumulus clouds, otherwise known as flammagenitus or “fire clouds,” develop due to “convection initiated by heat from forest fires, wildfires or volcanic eruption activity,” according to the World Meteorological Organization.

GRAND CANYON NATIONAL PARK, Ariz. - A New Jersey man has been missing for about a week as a "mega-fire" ravages the Grand Canyon National Park.  Thomas Daniel Gibbs, 35, of Freehold, New Jersey, was last heard from by his friends and family at approximately 12 p.

Grand Canyon 'megafire' time lapse footage shows heat forming clouds of fireSource: Cliff Berger/TMX