why-could-cloudbursts-become-more-frequent

Context: Recently, cloudbursts have been reported from several places in J&K, Union Territory of Ladakh, Uttarakhand and Himachal Pradesh.

About Cloudburst:

  • A 2017 study of cloudbursts in the Indian Himalayas noted that most of the events occurred in the months of July and August.
  • Cloudbursts are short-duration, intense rainfall events over a small area.
  • According to the India Meteorological Department (IMD), it is a weather phenomenon with unexpected precipitation exceeding 100mm/h over a geographical region of approximately 20-30 square km.
  • During the cloudburst, the relative humidity and cloud cover was at the maximum level with low temperature and slow winds.

Impact of Cloudburst:

  • Cloudbursts are especially common in mountainous areas. 
    • This is probably because the warm air currents of a thunderstorm tend to follow the upward slope of a mountain. 
  • The effects of heavy rain are especially striking on mountain slopes because the falling water is concentrated in valleys and gullies. 
  • Mountain cloudbursts cause sudden and destructive floods.

The meteorological factors behind the cloudburst:

  • Atmospheric pressure, 
  • Atmospheric temperature, 
  • Rainfall, 
  • Cloud water content, 
  • Cloud fraction, 
  • Cloud particle radius, 
  • Cloud mixing ratio, 
  • Total cloud cover, 
  • Wind speed, 
  • Wind direction, and 
  • Relative humidity during the cloudburst, before as well as after the cloudburst.

Cloudburst Frequency:

  • Several studies have shown that climate change will increase the frequency and intensity of cloudbursts in many cities across the globe.
  • In May, 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.
  • 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. 
  • Also, there is evidence suggesting that globally short duration rainfall extremes are going to become more intense and frequent. 
  • With warming climate or climate change, we will surely witness these cloudburst events in increased frequency in the future.

Predictability of Cloudburst:

  • Various climatologists cited that it's an extremely challenging task and is very difficult to model cloudburst.
  • For hourly rainfall and cloudbursts, it is very difficult to simulate the intensity and location.

Disaster Management:

  • The government has announced an ex gratia of ₹5 lakh each for the next of kin of those who lost their lives, and ₹50,000 and ₹12,700 under the State Disaster Relief Fund (to the grievously injured).

Source-1:https://www.thehindu.com/todays-paper/tp-national/kishtwar-cloudburst-rescue-operation-resumes-to-trace-19/article35618311.ece

Source-2:https://indianexpress.com/article/explained/explained-cloudbursts-frequent-jk-uttarakhand-himachal-pradesh-imd-7428954/