John Farley
09-03-2007, 12:22 AM
I observed an interesting phenomenon yesterday in Santa Fe, NM. At an art show in the parking lot of a small shopping center, I, along with several others, noticed a small whirlwind in the parking lot. Nothing unusual about that in this area. But here is what was interesting: The whirlwind lofted up a plastic baggie - but after the whirlwind died out, the baggie just kept rising. Several of us watched it continue to rise until we lost track of it around 250-300 feet above the ground. It never dropped back down that we could see, so I am inclined to think it just kept rising. At the time, there was a moderate cumulus cloud just east or NE of our location, drifting to the west or southwest. A few minutes later it had become a TCU more or less overhead, and by 20-30 minutes later it had become a thunderstorm a couple miles to the west or southwest of our location. I am inclined to think that this convection helps to explain why the baggie just kept rising. In any case, I would say a baggie works pretty well as a way to visually approximate the movement of a parcel in a convective environment.