As a child you probably squealed in joy as you ran towards it or in terror as you scampered in its opposite direction.
Your parents probably succeeded in instilling in you a healthy fear of them by telling you that they were passing ghosts.
Whatever your experience might have been, you must have wondered at some point - what brings about whirlwinds?
A Whirlwind is a weather phenomenon in which a vertical and rotating column of air forms due to differences created between colliding air currents.
They occur all over the world and at any season.
Whirlwinds are subdivided into two major categories; major whirlwinds and lesser whirlwinds.
An example of a major whirlwind is the tornado. The tornado is formed when a major thunderstorm starts to spin and then it meets with other high altitude winds, causing a spinning funnel. A cloud then forms over the funnel thus making it visible.
Minor whirlwinds, on the other hand, are created by local winds and typically start on the ground.
The colliding wind currents then form a funnel which then moves over the ground, being pushed by the winds that first formed it.
The funnel then picks up materials such as dust or snow as it moves over the ground, thus forming the dust devil or the snow devil respectively.
There are other middle whirlwinds such as the gustnado and firewhirl which form much the same way and differ in intensity.
Whirlwinds are known to be accompanied by gust winds that reportedly reach up to a speed of 150km/h and above. Also, they have been known to cause widespread destruction to buildings and other things.
In other words, whirlwinds are not ghosts, they are simply winds that collides while moving in opposite directions.