Quote:
Originally Posted by ZenGum
We're moving well into spring now, so in the Outback (Thargomindah, Qld in particular) the forecast is for hot dry weather, smoke haze, strong winds, with a chance of fire elementals in the 4 to 6 hit dice range.
Attachment 41351
Okay technically that's a piddly little tornado (note the outdoor toilet or "dunny" on the right for scale) which is sucking up a pre-existing bushfire. I've seen things like this in bushfire footage fairly often. Without the fire we'd call it a willy-willy. With the fire, I don't know if it has a common name. Fire tornado? Firenado? Firespout? Fire devil? Firewilly?  |
first of all, that is a great picture! very dramatic.
Quote:
Originally Posted by glatt
willy willy, huh? We'd probably call that a dust devil.
Don't think we have a name for it when it's sucking on a fire.
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"sucking on a fire"... I see atmospheric phenomena like this from time to time, (never on fire though) and I always think about where and how the flow is moving. this is how I see it and understand it.
When you take a bath, and you pull the plug from the drain, the water swirls and forms a cone, right? same thing's happening in a tornado or a hurricane or a firewilly. In the bath, there's a layer of heavy dense water above a layer of light less dense air. In their struggle to swap positions, the water swirls downward and leaves a tube through which the air may swirl upward.
That's exactly what we're seeing here. The hot air around the burning ground and brush is less dense than the cooler air layer above and it wants to rise as the cooler air wants to press downward. The easiest way to do this is to swirl and the fiery air can now flow up and away from the pressure of the layer above. Same thing in a tornado. Warm air near the ground, colder stormy air above, when they try to swap, they do so in a swirl, a tornado.
Most times, you can't see the funnel of air, unless there's something in it like dust or in this case, fire. Very cool picture!