Dust Devil Whirlwind At Ligao National High School in Albay Philippines (VIDEO)

This video of the so-called Dust Devil whirlwind has gone viral on social media. Also called “dancing devil”, “sand auger” or “dust whirl”, the whirling wind appeared, disappeared, and then reappeared countless times at an open area at the Ligao National High School in Albay, Philippines.

You see on the video student spectators being amazed by the intermittent wind show.

VIDEO

Dust devils are usually harmless, but can on rare occasions grow large enough to pose a threat to both people and property.

What is Dust Devil
Dust devils form when hot air near the surface rises quickly through a small pocket of cooler, low-pressure air above it. If conditions are just right, the air 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. [Source: Ludlum, David M. (1997). National Audubon Society Field Guide to North American Weather. Knopf. ISBN 978-0-679-40851-2.]