Cloudbursts in India
Context
In the wake of recent episodes of extreme rainfall in the Himalayan region, attention has once again turned to cloudbursts. These highly localised weather events remain difficult to forecast, highlighting the need for improved weather prediction systems and better disaster preparedness.
Key Highlights
- As per the India Meteorological Department (IMD), a cloudburst is defined as rainfall of 100 mm or more within one hour over a limited area of approximately 20–30 sq. km.
- Cloudbursts occur predominantly in mountainous regions, where moisture-laden air is forced to ascend steep slopes (orographic lifting), resulting in rapid condensation and extremely intense rainfall.
- Although such events are relatively uncommon, climate change is increasing atmospheric moisture, which may contribute to a rise in the frequency and intensity of extreme rainfall episodes.
- Experts emphasise that the damage caused by cloudbursts is often amplified by unplanned urbanisation, deforestation, encroachments, poor drainage infrastructure and construction in hazard-prone areas.
- To improve short-term weather forecasting, the IMD is expanding Doppler Weather Radar (DWR) coverage, strengthening observational networks and implementing Mission Mausam.
Key Concepts
- A cloudburst is an extremely intense and highly localised rainfall event occurring over a short period, often triggering flash floods and landslides.
- Orographic rainfall occurs when moisture-bearing winds are forced to rise over mountain ranges, leading to cooling, condensation and heavy precipitation.
- Flash floods are sudden floods caused by intense rainfall that exceeds the soil’s infiltration capacity, resulting in rapid surface runoff.
- Doppler Weather Radar (DWR) provides real-time information on rainfall intensity, storm movement and severe weather systems, improving forecasting accuracy.
- Mission Mausam is an initiative aimed at modernising India’s weather forecasting infrastructure through advanced observation systems, improved modelling capabilities and enhanced early warning mechanisms.
Way Forward
India should strengthen high-resolution weather forecasting, expand real-time monitoring systems, enforce scientific land-use planning in vulnerable regions, improve disaster-resilient infrastructure and promote ecosystem-based measures to reduce the impacts of cloudbursts and other extreme weather events.