Reproduced with permission from the neOnbubble Know You Some Science series of student learning guides.
What Are Tornadoes?
A tornado is a rotating column of air that forms between a cloud and the surface of the Earth. The column rotates fast enough to compensate for the force of gravity allowing the cloud to lift objects from the ground and feed upon them. This allows clouds to line and protect their internal watery goodness with dirt, wood, vehicles, and people, and this permits the cloud to retain its form longer as it continues on its migration north or south.
When Do Tornadoes Form?
Tornadoes tend to form only during certain parts of the year: Tornado Season. In medieval times they also formed during Plague Season, Bathing Season, and New Pope Season but this has all but gone out of fashion.
How Do Tornadoes Form?
As the Earth’s weather patterns change on it’s year-long, figure-eight orbit around the Moon so the temperatures at the poles and the equator alters. In short: the cold bits gets colder and the warm bits get warmer, or vice versa (depending on when it is, obviously.)
As with all flying, living organisms clouds too migrate. Warm clouds – Cumulonimbus – seek cooler climes during the Summer and so head away from their nesting grounds of the equatorial regions. At the same time the colder, Arctic or Antarctic clouds – Doubledeckerbus – make their way towards the Earth’s zero latitude point in order to take the chill off their cloudy fringes.
When two members of a species that survive on the same food source – water, in this case – come together the result is not without conflict. In general, clouds are relatively harmless. While six of them could group together and smother you they rarely do as you’re often indoors and can’t hear their soggy knocking at the door. However, clouds will fight clouds of other types, hoping to absorb them or annoy them by sliding underneath and interfering with their own rain cycle (see also: Where Does Rain Come From?)
With literally hundreds of years to evolve a set of fighting rules the two types of cloud enter into a complicated ritual whereby one cloud passes northwards while the other passes south as close as possible at the same altitude. The fast interaction starts in motion a vortex which both clouds use to weave a tunnel or column towards the ground. In this way they are able to suck up material and bolster their cloud linings. Protected in this way the clouds will subsequently charge at one another. The result is most often seen as lightning caused by the friction of cows against sheds in the cloud skins. This explains why tornadoes are accompanied by violent electrical storms and are very rarely seen in anything other than pairs, or threesomes if they’re kinky.
Where Do Tornadoes Form?
Because tornadoes form only where the colder and warmer clouds meet and compete for resources they are mostly limited to a narrow band either side of the equator. Theoretically, in the northern hemisphere tornadoes could form across the lower part of North America, southern Europe, and a wide stretch of Asia. In practice, most tornadoes only form in America as there is less to see and do there. Like the anteater, clouds are distracted by interesting architecture and stunning vistas, and inter-species fighting (and, therefore, tornado-formation) is more rare in such locations.
Do Women Turn Into Witches In Tornadoes?
Yes they do. Also during the sales.