What is a
· A tornado is a very violent
· In a tornado the air is concentrated (pushed
· The air whirls upwards rapidly.
· A tornado is grey in colour and looks like an elephant’s
trunk swaying down from the clouds to touch the ground with its tip.
· A tornado is only a tornado if it touches the
ground. If the tip of the ‘elephant’s trunk’ does not touch the
ground, the storm is known as a funnel.
· A tornado moves across the country. It moves at a speed of between 25 and 90 miles per hour.
· It can cause much destruction.
· Tornadoes happen in every continent of the
· The most dangerous tornadoes happen in the southern
states of the USA.
· There is an area through Texas, Oklahoma, Kansas,
Nebraska and Dajkota which is called Tornado Valley.
· In the central areas of the continent of America there
are usually about fifty tornadoes a year.
· There have been some very small tornadoes in Britain
that have damaged buildings, but this is unusual.
How big is a
· A tornado usually has a diameter (the measurement from
side to side) of only 25 to 50 yards.
What causes a
· Scientists are not sure of all the causes of
· Tornadoes happen when a cold wind high up meets warmer
air and warmer winds lower down.
· This causes the winds to swirl and the warmer air from
below rushes upwards at terrific speed.
· As the tornado moves forward, this warm wind rushing
upwards can pick up any objects in its path. (Look below for a
description of the tornado that hit Annapolis in 1925.)
What is the
difference between a tornado and a hurricane?
· A hurricane can be as much as 400 miles from side to
· A tornado is much smaller, with a diameter of no more
than 50 yards.
· A hurricane has a small area in the centre, known as ‘the
eye of the storm’, which is calm. If you are in the centre, or eye, of
a hurricane, there is dead calm and a blue sky above you.
· A tornado has a centre core of violent ascending currents
of air. The centre of the tornado is the most dangerous
· A hurricane forms first at sea and can move towards the
· Tornadoes are formed on land. A storm like a tornado but which forms at sea is called a
What damage can
a tornado do?
This photograph from
2007 shows the damage a tornado can do!
Some tornadoes have
caused terrible damage and loss of life. One of the worst was in
March 1925 when a tornado hit the town on Annapolis in Missouri, USA.
It was a calm sunny
afternoon and children were playing marbles in the street. The sky
was clear and blue. Suddenly on the horizon people saw a black cloud shaped like an ice-cream
cone. It raced down on the town at terrific speed, bringing with
it a wind of 150 miles an hour.
With a deafening roar
the tornado tore through the streets, leveling everything in its path. Solid stone buildings were torn apart, passenger trains were turned over and
smashed, fifty cars were swept up and carried over the rooftops.
The tornado’s path was
less than 250 yards wide but it left a terrible scene behind it, with 823 people killed and nearly 3,000
People who live in
Tornado Valley in America build cellars, or storm shelters, beneath their homes so that they can take shelter if a tornado comes.