UPSC Mains 2024 GS1 Q6: What Is a Cloudburst? Explain the Phenomenon

A cloudburst is an extremely intense burst of rainfall over a small area in a very short time. The India Meteorological Department generally defines it as about 10 cm of rain in an hour.

A cloudburst forms inside a towering cumulonimbus cloud. Strong updrafts hold raindrops suspended in the air instead of letting them fall gradually.

As suspended water keeps accumulating, it eventually grows too heavy for the updraft to support. All of it releases at once, producing a short, extremely intense burst of rain.

Cloudbursts are especially common in mountainous terrain like the Himalaya. Warm, moist air rises sharply against steep slopes, a process called orographic lift, intensifying the storm.

Cloudbursts affect just a few square kilometres and usually last under an hour. This makes them a distinct, localized event, not just an intense version of ordinary heavy rain.

So much rain falls in so little time that cloudbursts routinely trigger sudden flash floods below, with almost no warning time for people downstream.

In steep mountain terrain, the sudden runoff can trigger landslides and debris flows, adding a second hazard on top of the flooding itself.

The 2013 Kedarnath disaster in Uttarakhand, triggered by intense rainfall and cloudburst-like conditions, caused catastrophic flash floods and landslides.

A cloudburst’s small size and short duration put it below the resolution of most weather radar and forecast models, especially in remote terrain with sparse monitoring. This is why it often strikes with little warning.

Define the phenomenon and explain the updraft-and-release mechanism, then cover its orographic trigger, its distinct microscale nature, its main consequences, and why it remains so hard to forecast.