Yesterday I made my way across the desert. Slowly because it’s always a difficult trip for me physically, and a little worse this time because of some other health issues I’ve had going on the past couple of weeks. But, by going slowly and taking many long breaks that allowed me to walk around a lot, I made it to my parent’s before the sun set. It was a 10 hour drive this time. I think I’ve taken longer. I let Sue know when I arrived, she gave me the weather report for Hereford. They had been having thunderstorms for quite a while. The dogs absolutely hate the thunder; I’m not sure that the cats enjoy it either. It hadn’t really rained, and that was good – because of the chickens – and bad – because we need the water. She sent me a photo, though, that shows it was raining not too far from us.
Crazy days. I didn’t really have any weather issues on the trip over. I did see an amazing number of dust devils though. Which is rather funny, because our sermon this Sunday had been based around dust devils… and there I was in the midst of them. One overtook my car in Gila Bend and shook me around a bit, but didn’t steal me away to Kansas, luckily! We see these often as we’re driving around the area. Sue usually says, someone’s driving a car out there, and I’m usually of the opinion that they’re actually a weather phenomenon. We’re probably both right about 50% of the time. I saw so many on the way over this time, it got me thinking; are they created the same way that water spouts are created? Are they related, meteorologically?
According to the American Meteorologic Society: Dust devils are occasionally strong enough to cause minor damage. Diameters range from about 3m to greater than 30 m; their average height is about 200 m, but a few have been observed as high as 1 km or more. They have been observed to rotate anticyclonically as well as cyclonically. Although the vertical velocity is predominantly upward, the flow along the axis of large dust devils may be downward. Large dust devils may also contain secondary vortices. Dust devils are best developed on a hot, calm afternoon with clear skies, in a dry region when intense surface heating causes a very steep lapse rate of temperature in the lowest 100 m of the atmosphere.
Does anyone get that? So- here’s a definition, from Wikipedia, that maybe easier to understand: Dust devils form when a pocket of hot air near the surface rises quickly through cooler air above it, forming an updraft. If conditions are just right, the updraft may begin to rotate. As the air rapidly rises, the column of hot air is stretched vertically, thereby moving mass closer to the axis of rotation, which causes intensification of the spinning effect by conservation of angular momentum. The secondary flow in the dust devil causes other hot air to speed horizontally inward to the bottom of the newly forming vortex. As more hot air rushes in toward the developing vortex to replace the air that is rising, the spinning effect becomes further intensified and self-sustaining. A dust devil, fully formed, is a funnel-like chimney through which hot air moves, both upwards and in a circle. As the hot air rises, it cools, loses its buoyancy and eventually ceases to rise. As it rises, it displaces air which descends outside the core of the vortex. This cool air returning acts as a balance against the spinning hot-air outer wall and keeps the system stable. The spinning effect, along with surface friction, usually will produce a forward momentum. The dust devil is able to sustain itself longer by moving over nearby sources of hot surface air.
While investigating Water Spouts, I couldn’t find a similar type of definition. They usually form on the edge of a weather system. FairWeather Water Spouts form on the surface of water and move upward, similar to the Dust Devil, but I can’t find out exactly why. I suppose it will remain one of those unanswered questions. Maybe one of you can figure that out for me. We’ll just remain with our desert dust devils and gorgeous sunsets, since there really aren’t any large bodies of water around us to cuase worry about water spouts anyway. It was just one of those questions that pass through the brain while you’re driving through the desert. Here’s a sunset photo that I hope will inspire you to visit us! Until then, as always~
Thanks for reading.
Today’s Weather: Checked in with Sue this morning. She said they had very high winds all last night. Upwards of 42 mph. Still strong gusts through out the day, only calming down within the last hour. She’s hoping for a very quiet night. According to my weather app., it was 92° in Hereford today, looking at an overnight low of 63° and a high tomorrow of 94°. Hopefully that’s a bit of relief.
Egg Report: Sue has been great about sending the egg report. Thursday -1 duck egg and 34 chicken eggs. Friday – 1 duck egg and 32 chicken eggs… maybe they didn’t like all that wind. Chickens are sensitive little buggers.
Cool Sighting: Sue sent me this shot of a spider under the watering bucket thing in one of the chicken coops. Not a black widow at least… any ideas? White widow?