As we’ve all heard on the news, summer 2011 has been hot, hot, hot. Some places in Oklahoma have had high temperatures above 100 oF for over a month, overlapping with areas of exceptional drought.
Needless to say, chase season has been pretty dead down south. The jet stream has shifted north toward Canada, and we’re ridged out. I’ve had to content myself with watching storm videos shot by my northern bretheren. So far, my favorite has been this one from Roger Hill (especially around 2:30 in – wow!).
Here’s the recipe for dust devils:
- Sunshine. The Oklahoma sun has certainly not been in short supply of late! A few clouds are okay, but you want to be in sunshine a majority of the time. Peak daytime heating (which occurs at local noon) is best.
- Light winds, < 10 mph. If the winds are too strong, the dust devils will be sheared over and weak. We check the Oklahoma Mesonet wind maps before heading out.
- A dry, open field, preferably freshly plowed, and with fine soil particles that are more easily lofted.
- Patience. We sit in place for up to an hour at a time in the blistering sun, with very little breeze to offer us relief. With the punishing heat we’ve been experiencing, we also pack ample beverages and sunscreen.
On our last chase, we saw dust devils every 5-10 minutes, usually on the leading edge of microscale gust fronts. As the dust devils passed by us, the breeze would usually kick up, and often, we were passed by dust devils on both sides. Most were short, weak, and transient, but a few (like the one pictured) lasted several minutes, and sent a tower of red dirt over 50 m in the air. Not bad!
Dust devil chasing is relatively easy and safe compared to storm chasing. Dust devils may not be a tornadoes, but they rotate, they’re convective, and unlike a tornado, you can drive or run through one safely (literal “chasing”!). I could easily see dust devil chasing being an educational parent-child activity, particularly if the child has any inkling that they want to chase storms when they get older. They would have to interrogate the surface observations, make a forecast, and navigate to a good viewing spot. They would learn that the best things come to those who wait. And, there would be a much greater likelihood of (repeated) success!
Robin, if you want dust devils, come to southwest Texas. The combination of extremely dry soils, intense insolation, and burn scars with lots of black ash make for some impressive whirls. Saw three while driving home from work yesterday afternoon. Stopped to let one wash over me Monday and witnessed a few subvorticies within the main vortex. A few have features resembling low level inflow jets, even. Go down toward Balmorhea and Saragosa and they’re literally ALQDS, some reaching heights estimated at well over 100m. Was driving back from Ft. Davis in mid June and counted 11 dust devils ongoing at one time, some dirty, some with nice hollow cores.
We just had a good size dust devil come through my neighborhood. I noticed the wind picked up just west of me and was heading my direction. Debris from the ditches started picking up and swirling around in the air. As it passed by me it picked up one of our lawn chairs and proceeded north east across the road to our neighbor’s property. Of courst our lawn chair was destroyed, it was blown into our neighbor’s fenceline. It picked up our neighbor’s trashcans, swirled them around and set them down. It went northeast then changed direction to straight north. By this time it was in our other neighbor’s back yard and had picked up quite a bit of dust. It looked fairly tall and was well defined as it traveled north. Our neighbors’ horses at first weren’t spooked by it, as it got closer to them they scattered.
This isn’t my first time seeing a dust devil, growing up and living in various places in Oklahoma I’ve seen my fair share. This was one of the biggest I’ve seen though.
Happy Hunting during this dry season. As much as I like summer, we definitely need rain. Grass isn’t supposed to crunch when you walk on it. lol 🙂
Aha. I live in Colorado, and we get some dust devils here. One tore the doors right off my barn! Lol. It was funny. It also made our little stray cat know how birds feel, for it was flung into the air. But it landed on its feet.