Tornadoes Did you know that tornadoes are one of the most spectacular forms of ex-

treme weather on the planet? A tornado is a furiously whirling funnel that can

suck up anything in its path. Amazingly, they have even been known to crush

entire towns!

How does a tornado form?

Most tornados form from thunderstorms. When warm air and cool air meet,

they create an unstable atmosphere. Air rises gradually and starts to rotate. If

a tornado picks up torn off branches and parts of buildings, the debris flies

chaotically around the funnel at high speed. Scientists still don’t understand

how and why tornados finish, but they are still researching and learning more

about this incredible phenomenon.

Are tornadoes dangerous?

Although most tornadoes

have quite narrow funnels,

they can cause a lot of

damage if they hit your

house… violently ripping off

roofs and destructively

blowing out windows. In

Tornado Alley, houses are

built with an underground

cellar with a strong door so

that you can shelter and

survive if a tornado hits.

Tornado Alley

Snowstorms Snowstorms can transform the world into a winter wonderland, but

they can also be deadly. This extreme weather has even been known

to destroy entire villages! On the afternoon of 23rd February 1999, a

slab of snow weighing 170,000 tonnes broke away from an Austrian

mountain slope forming a deadly avalanche. It roared toward the vil-

lage of Gultur, destroying everything in its path and crushing 30 peo-

ple to death.

How does snow form?

Snow forms when tiny ice crystals in clouds

stick together and gradually form snowflakes.

This happens very high up where the air’s tem-

perature is below 0°C, the freezing point of

water. If the air close to the ground is also

cold, the snow will settle there and not melt.

Amazingly, some places are so cold that the

snow stays there all year round!

Are snowstorms dangerous?

Apart from avalanches, snow can effect travellers in cars. Drivers

need to be especially careful not to slip and slide around on the icy

roads. During heavy snowstorms, it is possible there is so much

snow that you can hardly see in front of your vehicle. This is called a

“white out”. Slow right down and drive carefully if you find yourself

in these conditions.

Snowflakes come in an amazing varie-

ty of shapes, but usually have six

sides. No one has ever found two the

same.

Thunderstorms When the air around you feels muggy, when a rumble can be heard, when a light

pieces the sky… beware, because a thunderstorm is on its way! Thunderstorms

are very loud, and have been known to cause chaos among people all over the

world.

How do thunderstorms form? The flash, called lightning, is what we see when a gigantic spark of powerful elec-

tricity jumps from a storm cloud to the ground. When lightning superheats the

air, the air explode powerfully outwards. Interestingly, this causes a very loud

sound wave that can be heard miles away.

Why Does Lightning Come Before Thunder?

The light created in a lightning bolt travels at the speed of light: 300,000 km per

second. Sound waves are roughly a thousand times slower travelling about 300

km per second. Unless a thunderstorm is directly above you, we usually see the

flash before we hear the bang.

Although thunder and lightning can be exciting, the energy released by the light-

ning is so powerful that it has been known to kill anyone it hits. While a thunder-

storm is raging, you should get out of swimming pools and ensure you are under a

solid shelter. Don’t shelter under a tree or stand up on open ground.

L i g h t w a v e s t r a v e l v e r y , v e r y f a s t !

))))))))))) Sound waves are much slower. The light reaches the boy before the sound.

Are thunderstorms dangerous?

Hurricanes Board up your windows! Stay indoors! A hurricane is coming your

way! Hurricanes have caused destruction in all over the world. They

are the largest, most violent and most destructive storms our planet

is capable of producing.

How do hurricanes form?

Hurricanes form from small storms over

tropical oceans. Fed by humid air ris-

ing from the warm ocean, they grow into a

monstrously swirling mass of cloud as they

drift westward. The most deadly winds oc-

cur in the eye wall, a circular wall of cloud

surrounding a central hole called an eye.

Winds speeds can reach more than 240 km

per hour in the eye wall.

Are hurricanes dangerous? Most people who die in hurricanes are killed by the sea. The eye of

the storm has been known to powerfully suck up the sea beneath

it by as much as 6m. At the same time, chaotically swirling winds

gradually whip up waves as tall as houses. These two things to-

gether produce a “storm surge” - towering walls of sea water that

surge inland for kilometres, sweeping away boats, trees and build-

Although the UK hasn’t experienced any hurricanes, many countries

in Asia and South America are not as lucky. Interestingly, the ef-

fects of hurricanes can often be felt in nearby countries. For exam-

ple, a recent hurricane in the Philippines caused 3 days of almost

continual rain in Thailand!

From space you can clearly see the eye

of this hurricane about to hit the United

States.