Cloudburst

Source: The Indian Express

Relevance: GS I – Geographical Features

Why in News: 

Severe damage was recently caused by hail and torrential rain in Jammu and Kashmir’s Ramban area.

What is a Cloudburst?

A cloudburst is a localized, very heavy rainfall event that occurs over an area of roughly 10 km × 10 km and lasts for at least 10 cm in a single hour. A cloudburst is defined as even 5 cm of rain over the same area in 30 minutes.

Causes of Cloudbursts

Orographic Lift

Because of a phenomenon called orographic lift, cloudbursts are more frequent in hilly areas. This phenomena occurs as warm air rises up the mountainside and expands because higher elevations have lower atmospheric pressure.

Atmospheric Instability

The air releases its moisture as precipitation as it cools and expands. A sudden, intense downpour can occur when significant amounts of warm, humid air continue to rise and accumulate moisture without releasing it. Cloudbursts are hard to predict due to their localized character, and they can overwhelm drainage systems, causing landslides and flash floods.

Why Cloudbursts Are Common in the Himalayas

The Himalayas frequently see cloudbursts because of a number of causes, such as the region’s rough terrain, orographic lifting, and the impact of the Indian summer monsoon. Because of the steep topography, moisture-laden air may climb quickly and cool, causing condensation and cumulonimbus clouds to form. These clouds can then quickly dump a lot of rain. Furthermore, the region may see additional moisture due to the warmer air from the Indian Ocean, which raises the possibility of cloudbursts.

Impact of Cloudbursts

• Landslides are the most obvious consequence of a cloudburst. A landslide is a swift downward movement of a massive mountain mass. It affects car traffic and causes fatalities. 
• Another frequent consequence of cloudbursts is mudslides. It is a swift flow of dirt and particles that becomes stronger and more liquified when swift-moving water is added.
• These natural catastrophes can damage a region’s rich flora and fauna in addition to harming people. Numerous animals perish and trees are uprooted as vast tracts of woodlands flood. 
• Another significant effect of cloudbursts is land subsidence. Rapid and abrupt settling or sinking of the earth’s surface is referred to as land subsidence.

Why cloudbursts are hard to predict

• The IMD has maintained that, in contrast to cyclones, cloudburst forecasting is extremely challenging because of the dynamics of the quickly forming clouds over a relatively narrow area.
• Due to their small scale, there is no effective method for predicting cloud bursts. To determine the probability of a cloud burst, an extremely precise network of radars is needed, which would be unaffordable.
• Cloudburst reports have increased in frequency in recent years.