What Is a Cloudburst?

Cloudbursts are often accompanied by hail or thunderstorms.

What Is a Cloudburst?

A cloudburst is a localized weather phenomenon characterized by extreme amounts of precipitation over a short period of time within a small geographical area. A cloudburst is sometimes accompanied by hail and thunderstorms which are capable of creating disastrous flood conditions. Meteorologists state that rainfall from cloudbursts is usually showered with a fall rate greater than or equal to 4.9 inches per hour. Cloudbursts generally occur in mountainous regions, deserts, and interior regions of continental landmasses. They are highly unpredictable by nature and happen very abruptly. Nearly all recorded cloudburst are experienced in the Indian subcontinent where monsoon clouds drift from the Arabian Sea onto the Himalayas.

Formation Process

Cloudbursts are caused by a phenomenal condition known as orographic lift. They mostly occur during the onset of monsoons near mountainous and desert regions, and are formed when warm moist air masses on mountain foothills get lifted, leading to condensation and copious precipitation. Intermolecular forces between the water molecules get high due to a decrease in temperature or electrostatic induction causing lightning to remain in the clouds, thus creating hyperactive energy in the clouds. As the water molecules get denser, they are condensed but do not leave the clouds due to electro forces.

As water concentration increases, cumulonimbus clouds holding large droplets of water are formed. When these clouds can no longer hold the weight, there is a sudden outburst of over 72,300 tons of water at a falling rate of 4.9 inches per hour. Cloudbursts also occur when the water held in the clouds fails to fall as steady showers. This happens when warm air currents blow below the clouds, hence raindrops find it hard to fall through the current of warm air. When the clouds finally release the raindrops, they burst with great strength and ferocity.

Characteristics and Effects of Cloudbursts

The catastrophic nature of cloudbursts differs based on terrain. In the mountains, large volumes of water gain momentum as it flows in gushes, destroying structures, trees, animals and people, and as gravity increases in the gullies, it results in landslides and mudslides. In deserts and plains, cloudbursts cause waterlogging and flash floods. In most cases, cloudbursts are accompanied by lightning, thunder, strong gusts of wind and hail storms. In extreme circumstances, flooding associated with cloudbursts can shut down an entire city as people struggle to cope with the influx of water. The most disastrous cloudburst occurred in India in 2013, killing at least 5,400 people and destroying property in 4,200 villages. Other severe cloudbursts have been accompanied with tsunamis in the United States, Pakistan, and Bangladesh.

Historically, cloudbursts are considered rare occurrences. There are no defined techniques to predict their incidence. Nevertheless, a network of radars can be used to detect the likelihood of a cloudburst, but it is very expensive. However, areas that receive heavy rainfall and mountain slopes are prone to cloudbursts, and therefore should be avoided as places for human settlement. Global warming has been attributed to the increase of cloudbursts, especially in the Himalayas, where the effects are first experienced.


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