Thunderstorms

Thunderstorms

What are thunderstorms???• A thunderstorm is a storm with lightning and

thunder. Its produced by a cumulonimbus cloud, usually producing strong winds, heavy rain and sometimes hail.

WEATHER PHENOMENON CONTACT WITH THUNDERSTORMS

Temperature warm

Wind strong

Precipitation Heavy rain or sometimes snow, sleet, hail, no precipitation.

Clouds cumulonimbus

Front cold front

Why do thunderstorms form??• Thunderstorms are powered by the energy from the sun.

All weather on Earth is caused by the sun’s uneven heating of the planet’s atmosphere. As the sun heats some parts of the atmosphere, the warm, lighter air in those regions rises, creating a zone of low atmosphere pressure. Cool air rushes in, replacing the air that has risen and producing winds. Such winds then carry all kinds of weather, from sunshine to rain, hail and snow.

• Thunderclouds need moisture and warm, rising air to develop. In sunny weather, the sun’s radiation warms the ground which in turn and heats air near the surface of Earth. The sun also evaporates water from the surface of seas, lakes and from wet ground. The warm air rises, taking the water vapor with it. As the air rises, it cools and the water vapor condenses to from clouds.

• It can also develop in weather system called fronts, where winds blow warm and cold air masses together, and in mountainous regions, where warm, moist air is forced upward by mountain slopes.

When and where do thunderstorms develop?• Thunderstorms can strike anywhere on Earth, but they

usually develop in locations with warm, humid weather. As a result, they occur most commonly in the tropics, regions around equator. In many areas of Central Africa, Southeast Asia, and northern South America, thunderstorms happen more than 100 days each year.

• Thunderstorms also occur commonly in temperate parts of the world, especially during the summer. In these areas, storms often break in the afternoon or evening, after the heat built up. Thunderstorms occur much less frequently in such cold and dry areas as the polar regions or deserts.

The places on Earth with the most thunder

• Tororo, in Uganda, East Africa, holds the record for the greatest number of thunderstorms per year. Tororo experienced thunder an average of 251 days a year during the 10-days period between 1967 and 1976. The town of Bogor, on the island of Java, Indonesia, is another location that commonly experiences thunderstorms. In the United States, thunderstorms occur most commonly in the Southeast, particularly in Florida.

SAFETY IN THUNDERSTORMS People can stay safe in a thunderstorm by following a few simple

rules:• Seek shelter in a house or large building• Don’t use a telephone with a cord, expect during an emergency,

because electric current from lightning can travel down wires.• If you caught outdoor, never take shelter under a lone tree.• Stay away from metal objects such as bicycles and don’t use an

umbrella.• If you are swimming, leave the water as quickly as possible • In the flat terrain like a beach, crouch to avoid being the tallest

point in the landscape.• It is safe to sit in a car, be sure to close the windows and don’t

touch any metal parts.

Lightning conductor protect buildings by channeling electric current safely down to the ground. A metal rod fixed to the tallest part of a building is connected to a long cooper wire or cable that runs into the ground. If lightning strikes, electric current passes harmlessly down the cable. In additional, tall buildings protect shorter, neighboring buildings by attracting lightning.