Dave Porter of the Black Hills National Forest captured this image of a pyrocumulus cloud January 6 over a pile burning project southeast of Sundance, Wyoming.
A pyrocumulus over a pile burn is rare.
A pyrocumulus cloud is produced by the intense heating of the air from the surface. The intense heat induces convection, which causes the air mass to rise to a point of stability, usually in the presence of moisture. Phenomena such as volcanic eruptions, forest fires, and occasionally industrial activities can induce formation of this cloud.
An article posted earlier today about the bushfire in Western Australia had a photo showing a pyrocumulus cloud over the fire.