A huge dust devil formed on a highway in São Paulo, Brazil on September 22, 2017 and was recorded by Alysson Martins while passing by it.
A dust devil is rapidly rotating wind that is made visible by the dust, dirt or debris it picks up. Also called a whirlwind, it develops best on clear, dry, hot afternoons.
They can range from small (half a meter wide / 1.6 feet and a few meters tall) to large (more than 10 meters / 33 feet wide and more than 1 000 meters / 3 290 tall).
Dust devils are usually harmless, but can on rare occasions grow large enough to pose a threat to both people and property.
They are comparable to tornadoes in that both are a weather phenomenon involving a vertically oriented rotating column of wind. Most tornadoes are associated with a larger parent circulation, the mesocyclone on the back of a supercell thunderstorm. Dust devils form as a swirling updraft under sunny conditions during fair weather, rarely coming close to the intensity of a tornado.
Featured image: Huge dust devil on a highway in São Paulo, Brazil on September 22, 2017. Credit: Alysson Martins via David de Zabedrosky (@deZabedrosky)