• • Cloudbursts are short-duration, intense rainfall events over a small area.
  • It is a weather phenomenon with unexpected precipitation exceeding 100mm/h over a geographical region of approximately 20-30 square km.
  • In the Indian Subcontinent, it generally occurs when a monsoon cloud drifts northwards, from the Bay of Bengal or the Arabian Sea across the plains then on to the Himalaya that sometimes brings 75 millimetres of rain per hour.
• Occurrence:
  
  • The relative humidity and cloud cover is at the maximum level with low temperature and slow winds because of which a high amount of clouds may get condensed at a very rapid rate and result in a cloudburst.
  • As temperatures increase, the atmosphere can hold more and more moisture and this moisture comes down as a short very intense rainfall for a short duration probably half an hour or one hour resulting in flash floods in the mountainous areas and urban floods in the cities.
• Cloudburst are Different from Rainfall:
  
  • Rain is condensed water falling from a cloud while cloudburst is a sudden heavy rainstorm.
  • Rain over 100mm per hour is categorized as a cloudburst.
  • The cloudburst is a natural phenomenon, but occurs quite unexpectedly, very abruptly, and rather drenching.
• Impact of Climate Change:
  
  • Several studies have shown that climate change will increase the frequency and intensity of cloudbursts in many cities across the globe.
    
    • In May 2021, the World Meteorological Organization noted that there is about a 40% chance of the annual average global temperature temporarily reaching 1.5°C above the pre-industrial level in at least one of the next five years.
    • It added that there is a 90% likelihood of at least one year between 2021 and 2025 becoming the warmest on record and dislodge 2016 from the top rank.
  • It is seen that more cloudbursts are happening in Himalayan region because the decadal temperature rise in the Himalayan region is higher than the global rate of rising temperatures.
• Cloudbursts occur in hilly areas like Amarnath

Experts have said it is difficult to predict when exactly a cloudburst will occur, and there is little definitive data on the exact number of cloudbursts that occur in India. Due to their definition dealing with a very small area, it is difficult to accurately predict and identify cloudbursts immediately. However, they are more likely to occur in mountainous zones mainly because of terrain and elevation.

This is because, in hilly areas, sometimes saturated clouds ready to condense into rain cannot produce rain, due to the upward movement of the very warm current of air. Instead of falling downwards, raindrops are carried upwards by the air current. New drops are formed and existing raindrops increase in size. After a point, the raindrops become too heavy for the cloud to hold on to, and they drop down together in a quick flash.

A study published in 2020 examined the meteorological factors behind the cloudburst over the Kedarnath region, where a cloudburst aided the devastating 2013 floods. It found that during a cloudburst, the relative humidity and cloud cover was at the maximum level with low temperature and slow winds. “It is expected that because of this situation a high amount of clouds may get condensed at a very rapid rate and result in a cloudburst,” wrote the team.

Preventive measures to avoid destruction caused due to cloudbursts

• Localised monitoring
  Meteorological department has to set up localised weather monitoring system in order to track changes in climate, which could lead to cloudbursts events.
• Identify vulnerable areas
  Area mapping has to be created to mark all the areas vulnerable to cloudbursts. This will help in planning development and human habitation in the area.