What is the phenomenon of ‘cloudbursts’? Explain.
Approach · directive: “explain”
What it asks · Define a cloudburst, explain how it forms, where it strikes in India and why its impact is rising.
It asks 2 things — answer each
- Explain: what a cloudburst is (IMD definition)
- Explain: how it forms, where it strikes in India, why its impact is rising and how the risk can be reduced
Open with · The IMD terms a rain event a cloudburst when a station receives 10 cm (100 mm) of rain in one hour; confined to a small area, it turns mountain streams into flash floods within minutes.
Cover
- Definition: IMD threshold of 10 cm of rain in one hour at a station; very small in space and time.
- Formation: moist monsoon air forced up slopes (orographic lift) builds cumulonimbus clouds whose updrafts hold, then suddenly drop, their water.
- Where: mainly the Himalayan States and UTs during the monsoon; plains are not immune, but orography makes mountains more prone.
- Rising impact: climate change is raising Himalayan extreme rainfall; snowmelt and moraine instability add runoff (MHA, 2026).
- Exposure: buildings on river banks and debris fans, hydropower works and pilgrim traffic, as at Kedarnath in 2013.
- Forecast gap: nowcasting needs a dense radar network or very high-resolution models.
- Way forward: hazard zonation, no-build zones, slope stabilisation, radars and early warning; Himachal's Multi-Sectoral Central Team.
Close with · A cloudburst is a natural hazard, but whether it becomes a disaster depends on where and how the mountains are built upon.
Add value (verified)
- In August 2026 the Home Ministry told the Lok Sabha that expert assessments link the rising intensity and frequency of extreme rainfall in the Himalaya to climate change.Incidents of Cloudbursts — PIB, Ministry of Home Affairs, 11 August 2026 ↗“as a consequence of climate change, the intensity and frequency of extreme rainfall events are increasing in the Himalayan region”
- IMD defines a cloudburst as 10 cm of rainfall at a station in one hour.Frequently Asked Questions on Monsoon — India Meteorological Department ↗“If 10 cm rainfall is received at a station in one hour, the rain event is termed as cloud burst.”
- IMD: cloudbursts are hard to predict; nowcasting needs a dense radar network or very high-resolution models.Frequently Asked Questions on Monsoon — India Meteorological Department ↗“To monitor or nowcast (forecasting few hours lead time) the cloud burst, we need to have dense radar network over the cloud burst prone areas”
- IMD: mountains are more prone to cloudbursts because of orography.Frequently Asked Questions on Monsoon — India Meteorological Department ↗“Cloud bursts do occur at plains, however, mountainous regions are more prone to cloud bursts due to orography.”
- MHA (2026): accelerated snowmelt and moraine instability add to slope failures and runoff in high-altitude zones.Incidents of cloudbursts — PIB, Ministry of Home Affairs, 11 Aug 2026 ↗“Accelerated snowmelt and moraine instability contribute to off-season slope failures and high runoff in high-altitude zones.”
- A Multi-Sectoral Central Team with NDMA, CBRI and IITM experts was set up to study Himachal Pradesh's cloudbursts and floods.Incidents of cloudbursts — PIB, Ministry of Home Affairs, 11 Aug 2026 ↗“The Team comprises experts from the National Disaster Management Authority (NDMA), Central Building Research Institute (CBRI), Roorkee, Indian Institute of Tropical Meteorology (IITM), Pune”
Question: UPSC's CS (Main) 2024, GS Paper I — paper ↗. Approach: Minimalist IAS, checked 16 Oct 2026 (how we verify) — UPSC publishes no model answers. ·
Model answer· 214words · Minimalist IAS
The IMD terms a rain event a cloudburst when a station receives 10 cm (100 mm) of rain in one hour. Confined to a small area, it turns mountain streams into flash floods within minutes.
How a cloudburst forms
- Moist monsoon air
- orographic lift up steep slopes
- towering cumulonimbus clouds
- updraft collapses
- sudden deluge
- Why mountains: IMD notes orography makes mountains more prone; strong updrafts hold heavy raindrops aloft, then release them at once.
Where it strikes
- Himalayan belt: Uttarakhand, Himachal Pradesh, Jammu and Kashmir and Ladakh, largely in the monsoon; plains are not immune.
Why its impact is rising
- Warming: since then, the Home Ministry has told the Lok Sabha (2026) that climate change is intensifying Himalayan extreme rainfall; moraine instability adds runoff.
- Exposure: homes on river banks and debris fans, hydropower works and pilgrim routes; at Kedarnath (2013) a lake breach multiplied the toll.
- Forecast gap: too small and brief for most models; IMD says nowcasting needs a dense radar network.
Way forward
- Science and land use: a Multi-Sectoral Central Team (NDMA, CBRI, IITM) is assessing Himachal's disasters; hazard zonation, no-build zones along streams and Doppler radar alerts should follow.
A cloudburst is a natural hazard, but whether it becomes a disaster depends on where and how the mountains are built upon.
Prepared by Minimalist IAS to the answer standard of Shivam Singh (mentor, 7 years) · facts checked against official sources (how we verify) · updated 16 Oct 2026. UPSC publishes no model answers: compare your structure and coverage with this, then write your own.
