Thunderstorms and Cyclones
A thunderstorm is a high-speed wind that is accompanied by heavy rain (or hail),
lightning, and thunder.
What causes thunderstorms?
In hot, humid and tropical areas, the
temperature of the air over the land is very high.
This causes the air to move upward and
forcefully carry the water vapour present in the
air, to a higher altitude. At high altitudes water
vapour freezes to form water drops or hail which
falls on the Earth. This sudden rise and fall of hot
air and cold-water droplets causes lightning and
thunder, and results in what is commonly called
as a thunderstorm.
Thunderstorms
Cyclones
Water on the surface of the Earth absorbs
heat and changes to vapour. As water vapour
moves up higher in the atmosphere, it carries
this heat along with it. The higher regions of
the atmosphere are cooler. This condenses the
water vapour into water drops.
When vapour cools down, it releases the
absorbed heat into the atmosphere. The heat
thus released warms up the air, which once
again causes it to rise up. A low-pressure area
is thus formed and the air from the surrounding areas rushes in. This sequence of
events is repeated continuously.
Thus, this cycle is the result of the formation of a very low-pressure system with high
wind speeds revolving around it. This weather phenomenon is known as a Cyclone.
The low-pressure centre of a cyclone is known as the eye of the cyclone. It is very
calm i.e. the centre of the storm is actually free from storm and rain.
Formation of a cyclone depends on the factors like wind speed, wind direction,
humidity and temperature. Destruction Caused By Cyclones
Cyclones can cause a lot of destruction to our lives, property, communication
systems, and facilities. They cause floods and make the soil infertile. The rainfall
caused during a cyclone is so strong that a human cannot overcome it.
Safety Measures and precautions against these cyclones:
1 Never ignore the warning given by media against cyclones.
2. Avoid driving on a road filled it water, it might have got damaged because of
cyclone.
3. Do not touch fallen and broken power lines.
4. Do not drink contaminated water in a cyclone hit area.
Advanced technologies like RADAR & satellites have helped a lot in giving early
warning against cyclones, so that people can have enough time to evacuate their
homes and shift to a safer place. Also we have Anemometer to measure the speed of
the wind, so whenever there is a remarkable hike in the wind speed we get an Alert!
Tornadoes
In some countries Tornadoes are seen which
are actually a dark cloud having a funnel
shape and travelling at an average speed of
300 Km/Hour. But most of the tornadoes are
weaker and sometimes these are formed
within the Cyclones.
Tornadoes
