A thunderstorm is a storm with thunder and lightning within rain clouds. The thunderstrom results in sudden flashes of light and trembling sound waves, commonly known as thunder and usually accompanied with strong winds, heavy rain and sometimes snow, sleet, hail.

Thunderstorm formation

The atmospheric instability is the main reason for the thunderstorm i.e., the air in the lower atmosphere is warm and humid and upper atmosphere is cool.

Three stages of thunderstorm

1. Developing stage                                                                                

As the sun’s heat warms the air around, it becomes lighter and starts to rise up (updraft). It starts condensing reaching higher altitude and forms a cumulus cloud. The warm and humid air moves into the cumulus clouds in large volume and at high speed. The cloud begins to grow vertically to a height of 6 km. In this stage air in the cloud is dominated by updraft.

2. Mature Stage

When the cumulus cloud becomes very large and the water contents in it become very heavy, raindrops start through the cloud when the rising air can no longer hold them up. On reaching an altitude 12 km, the cold dry air starts to enter the clouds and formation of rain and hail stars and the clouds become cumulonimbus clouds. At this stage the clouds have an updraft of warm air and a downdraft of rain and hail. The hail starts descending and on collision with the clouds, hail gets positive and negative charges.The positive charge develops at the base of the clouds and negative charges develop on the lighter ice on the top of the clouds. Lighting is caused by the attraction of positive and negative charges. Thunder is caused by lighting. The cumulonimbus clouds are perfect thunder clouds and usually last for an hour or so. This is the most dangerous stage when large hail, damaging winds, and flash flooding occur. The reason we see lightning before we hear thunder is that light travels faster than sound.

3. Dissipating Stage

In this stage the downdraft cuts off the updraft. The warm moist air can no longer rise and cloud droplets can no longer form. The storm dies out with light rain as the cloud almost disappears.

Important facts about thunderstorms: Severe thunderstorms have one inch or greater hail and winds gusting at a high speed or tornoda.  Each year an estimated 16 million thunderstorms occur.The thunder of a thunderstorm won’t hurt you—lightning will! Thunderstorms affect small areas and last for less than an hour.

Effects of thunderstorms: It damages the property and trees, deaths to lighting hazards, and many others, catastrophic flooding, very strong winds. Lightning kills and injures people each year in the hundreds.

Zia Ahmed Khan , email: khanziaahmed@gmail.com

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