A huge dusty whirlwind swept through the city of Tempe in the US state of Arizona. A whirlwind spinning off the road was taken from the window of his car by a local news officer, Brad Anderson.
“Dust Devils”, as you know, have a diameter of one to five meters. This is a fairly common natural phenomenon in Arizona. In most cases, they do not pose a threat to people, but larger “devils” can be devastating.
The vortex movement of air occurs at the surface of the earth in cloudy weather, usually hot, with strong heating of the surface by the sun’s rays. A vortex is formed when cold air hits the ground sharply and rises in the form of warm air. A thrombus with a height of several to 20 meters raises sand, dust, stones from the surface of the earth and can carry them over considerable distances.