30 October: cloudbursts
Friday 30 October 2026
GS Paper 1 · 150 words · 10 marks
What is the phenomenon of 'cloudbursts'? Explain.
(UPSC Mains 2024, GS Paper 1, Q6)
You have seven minutes. Write your answer before you read anything below.
Open only after you have written
How to approach this question
The directive. Explain asks how something happens. Start with a precise definition, then the mechanism. Effects and examples come after.
A shape that works in 150 words.
| Part | Words | What to write |
|---|---|---|
| Definition | 30 | What a cloudburst is, with the IMD threshold |
| Point 1 | 40 | How it forms |
| Point 2 | 20 | Where it happens in India |
| Point 3 | 30 | Effects, with one named event |
| Point 4 | 15 | Why it is hard to forecast |
| Conclusion | 15 | One practical step |
Material you can use.
| Item | Detail |
|---|---|
| IMD working definition | About 100 mm of rain or more in one hour, over roughly 20 to 30 sq km |
| Cloud type | Cumulonimbus |
| Trigger | Moist monsoon air forced up steep slopes (orographic lift) |
| Effects | Flash floods, landslides, debris flows |
| Event | Leh, August 2010 |
| Measurement gap | IMD called the Amarnath floods of July 2022 localised heavy rain. The peaks above the shrine had no rain gauges |
| Warning tool | Doppler weather radar |
Mistakes to avoid.
| Mistake | What to do instead |
|---|---|
| A vague definition such as "very heavy rain" | Give the threshold, the time and the area |
| Writing mostly about disaster relief | Spend most words on how it forms |
| Several events named with no detail | One event, with what happened |
A model answer
A cloudburst is a short burst of very intense rain over a small area. The India Meteorological Department's threshold is about 100 mm of rain in an hour over 20 to 30 square kilometres.
How it forms. Moist monsoon air is forced up steep slopes. It cools into tall cumulonimbus clouds. Strong updrafts hold the water up. When they weaken, it falls at once.
Where it happens. Most Indian cloudbursts hit the Himalayan states in the monsoon. Narrow valleys channel the water.
Effects. Flash floods, landslides and debris flows follow within minutes. The Leh cloudburst of August 2010 killed over 200 people.
Forecasting. It is too small and brief for weather models. High slopes have few rain gauges. So IMD could not confirm a cloudburst at Amarnath in July 2022. Doppler radars give short warnings.
More radars and limits on building beside mountain streams would cut losses.
Word count: 147.
| Where | What earns credit |
|---|---|
| Opening | A definition with a threshold, time and area |
| Body | Mechanism first, then place, effects and forecasting |
| Conclusion | Two practical steps |