The India Meteorological Department (IMD) defines a cloudburst as any event where 10 millimetres of rainfall have fallen in a span of an hour over a region that is 20-30 square kilometres in area.
Mechanism of Cloudburst:
- Formation of Cumulonimbus Clouds: When moisture-carrying air moves up a hilly terrain, forming a vertical column of clouds.
- Orographic Lift: Such clouds usually cause rain, thunder and lightning.
- Raindrops, instead of dropping down, are carried upwards by the air current.
- New drops are formed and existing raindrops gain in size.
Occurrence in the context of Indian Sub-Continent:
- Mostly concentrated in the hills of Himalayas (Orographic).
- Sometimes in deserts due to rapid convection.
Recent examples of Cloud Bursts:
- Cloud Burst in Dehradun 2022
- Amarnath cave, 2022.
To monitor or now cast (forecasting few hours lead time) the cloud burst, we need to have dense radar network over the cloud burst prone areas or one need to have a very high resolution weather forecasting models to resolve the scale of cloud burst.