Key Terms & Concepts — UPSC Mains
Western Disturbance
"An extratropical storm from the Mediterranean region that brings winter rain and snow to northwest India"
A Western Disturbance is an extratropical storm that originates over the Mediterranean, Caspian and Black Sea regions and is carried eastward by the subtropical westerly jet stream to bring non-monsoonal rain and snow to northern and northwestern India, mainly in winter. As the system picks up moisture over the seas and rises against the Himalayas, it produces rainfall in the plains and snowfall in the mountains between roughly November and April. This precipitation is vital for rabi crops such as wheat, for replenishing Himalayan glaciers, and for regulating winter temperatures.
Relevant for GS1 (geography, climatology, Indian weather systems). Western Disturbances are the main source of winter precipitation in northwest India and directly affect rabi agriculture and water security. Studies show climate change is altering their frequency and intensity, sometimes causing untimely rain, hail or extreme snowfall, keeping the topic relevant for both Prelims mechanism questions and Mains climate-impact analysis in 2026.
- 1 Extratropical storms originating over the Mediterranean, Caspian and Black Seas
- 2 Steered into India by the subtropical westerly jet stream, mainly November to April
- 3 Bring rain to the plains and snow to the Himalayas, peaking in January and February
- 4 Around 4 to 6 significant disturbances occur each winter
- 5 Critical for rabi crops (especially wheat), glacier recharge and river flows
- 6 [object Object]
- 7 Climate change is shifting their timing and intensity, causing untimely rain, hail and extreme snowfall
In 2026, variability in Western Disturbances again shaped the winter, with their timing and intensity affecting wheat-growing regions of Punjab, Haryana and Uttar Pradesh and the snowpack of the western Himalayas.
