What are "mini-tornadoes"?

A friend just returned from the Outer Banks with an interesting story. While he was sitting on the beach on a clear, calm, sunny day, he looked down the beach to see beach umbrellas flying in the air, beach chairs, etc. They were 100 feet or so above the ground, spinning, flying around. The phenomenon moved down the beach toward him - people running for cover and also running to avoid being impaled by flying beach umbrellas. He ducked and the wind pretty suddenly died down. He said it lasted a total of about 45 seconds to a minute and it was over. Fortunately, no one was hurt very badly. People along the beach retrieved their stuff and battened it down better. 20 minutes later, another burst like the first occurred, in just about the same spot, but it was about half the strength. A long-time visitor to the Outer Banks (40 years) said he’d never seen or heard of such a thing before. I’ve certainly seen dust devils tear up a lot of paper and debris, but that sounded like a mini-tornado. Is there a name for this phenomenon? Dopers - any help understanding it? Thanks. xo, C.

Still a dust devil, just of unusually large size.

Or perhaps whirlwind?

Bingo! Calm, sunny day, flat surface, dust and sand available, area of lower temperature nearby. Nailed it. Thanks. xo, C.

Yes, dust devils can be remarkably strong and dangerous. A few years ago a man was killed not far from where I live when a dust devil caused the building he was in to collapse. See the second paragraph of this page for more details on that case.

Zowie. Those things are not just interesting little phenomena, as I always considered them. Jeez, there’s no place on Earth like the world. Totally amazing.

p.s. Seems as if Bibliophage has been absent for a bit. Nice to see him back. I know Cecil relies on him, and that’s good enough for me. xo, C.

Here’s a very well-documented dust devil. Yeah, those things can get pretty damned big.

(It starts about twenty seconds in)

:eek: :eek:

I was watching a pretty big one (nothing like the one in Japan) going across an empty field when it crossed into the yards of two houses. All of a suden two backyard beach umbrellas (the kind with pointed metal posta) were sucked up and whirling around about 25 feet in the air. Someone walking or driving nearby could easily have been impaled if those things were lower or when they dropped out of the sky.

I think we broke YouTube. That thing just will not play for me.

And of course they are very important on Mars where they aperiodically clean off the solar panels of the Mars rovers… :slight_smile:

Here is the link:
http://www.nasa.gov/vision/universe/solarsystem/mer-042105.html

The UK media have an annyoing habit of using the term “mini-tornado” for proper tornadoes in this country. (Presumably on the basis that “only America has real tornadoes”…)

Damn them in the UK! I say we secede!