What’s the Difference Between a Tornado and Dust Devil?
With the sighting of the first tornado in the Mid-Columbia this week since 2010 (that one was seen near Umatilla) we wondered - what's the difference between the commonly seen Dust Devils and tornadoes? The twister was seen near Rattlesnake Mountain Wednesday afternoon. (Photo courtesy of KNDU-TV-Michelle Bemis Morford).
One of the clowns at work said the difference is a Dust Devil plays baseball...haha! But actually there's no real relation between the two, despite their similar appearance.
According to about.weather.com, and the National Weather Service (NOAA), a Dust Devil occurs when the ground gets very hot, especially in dry, arid climates like ours.
The ground actually heats up the air, and of course, hot air rises. The hotter, the faster. It actually creates a vortex, or swirling air, and it picks up dirt and debris off the ground. Throw in some gentle breezes and you have a Dust Devil. The dirt and debris allows you to see the vortex in action, as it scurries along the ground, or races across farmland. They usually "run out of gas" or the air cools enough that they quickly go away.
A tornado, on the other hand, according to weather.about.com, occurs when to large air masses collide. When warm, moist air collides with cooler air, usually during a thunderstorm, a massive updraft usually occurs. That's a powerful, vacuum-like lift of air. The "dueling" air masses, and uplift, create a swirling funnel of air that feeds upon itself as long as the two different air masses continue to supply it with warm, moist air and cooler air. The larger the air masses, and larger the uplift, the more violent the tornado.
The reason we don't get tornadoes here is because we get largely dry winds. We don't experience the collision of warm-wet with cool, like they do in the Mid-West.
But occasionally, when we do, we see a rare, but weak tornado, like the one near Rattlesnake Mtn. It was seen as far away as Grandview. The National Weather Service confirmed Wednesday it was a tornado, although it had very "weak" winds of only 70-80 mph, and didn't last very long.
So, while a Dust Devil goes UP, a tornado starts from the top and goes DOWN. So now you know despite their resemblance, they have nothing in common, really. And a Dust Devil doesn't mean a tornado is on the way.