Whirlwind

A whirlwind is a phenomenon in which a vortex of wind (a vertically oriented rotating column of air) forms due to instabilities and turbulence created by heating and flow (current) gradients.

The range of atmospheric vortices constitute a continuum and are difficult to categorize definitively.

The funnel picks up materials such as dust or snow as it moves over the ground, thus becoming visible.

[1] Major whirlwinds last longer because they are formed from very powerful winds, and it is hard, though not impossible, to interrupt them.

Supercell thunderstorms, other powerful storms, and strong winds are seen with major whirlwinds.