How Dust Devils Form

The sun was high and bright as the temperatures were reaching nearly 99.8 degrees. The scorching rays were beating on my skin, as I was approaching the desert like landscape in my yard. I just recently had moved to Arizona but was already enamored of the many wild aspects of this State. I loved to hear the coyotes howl to moon, watch mesmerizing sunsets, feel the warmth of burning stones. Yet, there was so much more to discover. And in the midst of my thoughts, there it was… A tornado like shaped twister that was coming right my way. It was huge, like nothing I had seen before. A rush of adrenaline hit me abruptly, as I escaped back into my house to take shelter.

Within minutes, sand, small rocks, twigs and debris were shattering against my windows. My dogs were barking as I looked at the event astonished. Within seconds, it was gone. I looked out the window for it and saw it dissipate quickly just as it had appeared…

I then rushed to my neighbor’s home and she chuckled as I spoke to her breathless describing what I had just seen. “Darling, those are dust devils, they are very common here, they really do not do much harm other than send dust in your eyes. Just make sure if you are driving on the highway that you pull over for the really big ones”.

Dust Devils are also known as “Dancing Devils” or “Sun Devils”. The Navajo like to call them “Chiindi” meaning spirits of the dead. Depending on the direction they spin, the Navajo are able to tell if they are good spirits or bad spirits.

Fascinated, by these “dust devils” I was eagerly hoping to see more. Arizona was pretty generous, I almost got to see one every day around noon. I always had secretly wanted to see tornadoes up close, and the dust devils were the closest I could get without getting harmed.

Dust Devils however, unlike tornadoes, do not form in the same matter. It takes some hot air on the surface to become warmer than the air above, for a dust devil to form. Under these circumstances, the instable air will begin to rotate and stretch vertically. A funnel is formed as the hot air moves upward and in a circular motion.

If the dust devil is continouosly supplied with hot surface air, it will persist. If cooler air is met, then the dust devil will vanish in seconds. Dust devils seem more likely to form in flat desert areas on warm clear skied days. While they are mostly harmless, some however, have been known to grow significantly large with winds in excess of 60 miles per hour. The Coconino County Fairgrounds in Flagstaff Arizona, suffered extensive damage while some injuries were reported when a dust devil struck in September of 2000. The winds were as high as 75 mph, the equivalent of an EF0 tornado.

Dust Devils do not occur only in the Southwestern United States. They are frequently seen in Australia (willy-willy), Kuwait, Saudia Arabia, Iran and Jordan (djin), Egypt (fasset el ‘afreet), Kenya (ngoma cia aka) and Brazil (moinho de vento). Surprisingly, some dust devils have been also been reported to have been found on Mars.

Nothing really says Arizona more than the rattling noise of rattle snakes, coyotes howling to the moon and dust devils whirling in the scorching afternoon heat. I always look forward to summer now, so to see these amazing yet, harmless mini tornadoes go into action, as I capture their unpredictable movements on video or immortal them with my camera.