Strange 'coalnado' swirls over West Virginia coal mine
You've probably heard of dust devils whipping up sand on a baseball diamond, or hay on a field, but how about coal?
This 'coalnado' was captured at a coal mine in West Virginia, where it cut an impressive figure as the dark coal dust swirled high into the air. While this darker look may make the vortex seem a bit more intimidating, dust devils are generally weak vortices that form in hot, dry weather. When the ground is hot, rising pockets of air above it form an updraft that can, under the right conditions, begin to rotate. The vortex then acts as its own little low pressure centre, drawing in additional warm air from near the surface, along with debris like hay, or -- evidently -- coal dust.
In this case, the fact the coal dust is so dark probably helped to get the dust devil going, as the dark surface absorbed more heat from the sun than the surrounding area.
While they rarely do any damage, dust devil winds can reach speeds upwards of 100 km/h and can be up to 30 metres wide.
