Table of Contents
- Tornadoes are the most violent of all the storms, capable of picking up trees, cars, roofs and walls of buildings.
- Tornadoes generally occur in middle latitudes.
- They are very small in size and of short duration which makes weather prediction difficult.
- Tornados funnel can have the size of 90-460m in diameter.
- The velocity of winds revolving tightly around the core reaches more than 300 km per hour.
- The storms cause massive destruction on the way as they go.
- When looked at from the ground, the funnel appears dark because of the presence of condensed moisture and the dust and debris picked up from the ground by the whirling tornado.
- Tornadoes usually occur within a short duration and over a small area.
- Tornadoes may be found to be moving singly or in families of several individual tornadoes., they generally move in straight paths.
- When a tornado occurs it is wise to get beneath a piece of furniture in order to protect the head.
What Are Tornados?
A tornado is a violently rotating column of air with very low pressure at the center, which can be observed at a distance as an ice cream cone-shaped cloud formation. A tornado occurs mostly where there is a thunderstormand is often accompanied byhail. The wind with its great force causes massive destruction on its way. However, another name for a tornado is twister they are often used interchangeably.
Tornadoes generally occur in middle latitudes. A tornado that takes place over the sea is called ”water sprouts”. These violent storms are the manifestation of the atmospheres adjustments to varying energy distribution. The potential and heat energies are converted into kinetic energy in these storms and the restless atmosphere again returns to its stable state. Some of the characteristics of tornadoes are that they are of short duration, occurring over a small area but are violent. They are so small, quick to occur and short-lived to make their prediction very difficult. Excessive instability and steep lapse rate in the atmosphere are necessary pre-requisite for the formation of a tornado.
Other storms similar to tornadoes in nature are whirlwinds, dust-devils (weaker cousins of tornadoes occurring in drylands) and waterspouts (a tornado occurring over water surface). Fire whirls (small-scale, tornado-like circulations that occur near intense heat surface)
What Causes Tornadoes?
We can see tornadoes as miniature hurricanes even though sometimes tornadoes can form over tropical oceans, they are usually common over land.
A tornado usually occurs where there is a huge thunderstorm; this is formed when there is warm, moist air near the ground and cold dry air above the atmosphere. This creates wind shears, rolling columns of wind that spin above the space where the hot and cold air meet. (This takes place frequently in late spring and early summer over the Great Plains of the USA). Intense heat on the ground by the sun causes warm, moist air to rise. The warmer air, in turn, creates an updraft that takes one of the horizontal wind shears and moves it into a vertical position. The top of the updraft has two spinning columns on both sides of it; the larger columns overtake the smaller one and become the thunderstorm. At this point, the storm is able to expand due to the warm air being sucked into the spinning column. When this happens, the warm air cools and forms large cumulonimbus clouds.The strength of the updraft (the rising air) determines how much of the surrounding air is sucked into the bottom of the tornado. Because of the conditions under which tornadoes are formed, they can easily occur beneath thunderstorms and hurricanes. Two things help tornadoes to rotate violently:
- The Coriolis force
- The high-level jetstream passing over the top of the storm, which adds an extra twist to the tornado.
How are Tornadoes Measured?
The strength of a tornado is measured using two different measuring scales, the Fujita scale,, and the Pearson scale.
The Fujita scale rate tornadoes by damage caused using wind speed
The Pearson Scale
This is the length and width of the tornado path. Using these two scales, the potential damage and the area that is likely to be affected can be observed and predicted.
Where do tornadoes occur?
Tornadoes occur wherever there are severe thunderstorms, they are most numerous and devastating in central, eastern and north eastern USA, where an average of five per day are reported every May, Some of the world’s deadliest tornadoes have occurred in Bangladesh (a small country on India’s eastern border). Part of the reasons may be due to the absent of a sophisticated tornado prediction and advance warning system, the relatively high frequency of tornadoes and lack of sturdy shelters in Bangladesh.However, tornadoes are also common in Australia (15 per year), Great Britain, Italy, Japan and Central Asia. Most fatalities, however, occur in the USA, where between 1950 and 1978, 689 tornadoes were classified as killers.
Effects of Tornadoes
- Tornadoes typically killed 60 to 80 people per year and injured more than 1,500 in some parts of the world. Most of these deaths were a result of flying or falling debris which occur in the most violent tornadoes.
- This violent storm can pick up and carry away cars, roofs and walls of buildings, little wonder expertise advise people tostay away from windows and open areas such as auditoriums and hallways whenever they suspect the storm.
- Tornadoes just like any other natural disasters such as floods, cyclones, volcanoes, earthquakes have caused severe damage to live and property.
- The powerful wind is strong enough to uproot trees and economic crops that stand on its path as it goes.
- It is also capable ofdestroying a healthy soilby carrying away the top soil, which is essential for plant growth.
- The storms is considered the most powerful and destructive in the world, it cause severe damage to the environment by destroying pipelines; chemical containers, which can lead to contamination of groundwater with oil, raw sewage, dioxides, asbestos and other toxic pollutants.
- Animals are not left out where there is occurrence of tornadoes,in some cases, lots of animals have been injured and killed during this which has led to the destruction of the food chain and disruption of the whole environment.