Question map
The witner rains in north-western India are caused by the
Explanation
The winter rains in north-western India, particularly in regions like Punjab, Haryana, and Delhi, are primarily caused by 'Western Disturbances' or westerly depressions [2]. These are weak temperate cyclones that originate over the Mediterranean Sea and travel towards India, gaining moisture from the Caspian Sea and the Persian Gulf [2]. They are steered into the Indian subcontinent by the subtropical westerly jet stream, which blows south of the Himalayas during the winter months [1][t4]. These disturbances cause vital frontal precipitation that is essential for the survival of winter (rabi) crops like wheat [c1][t5]. While the retreating monsoon (North-East monsoon) brings rain to the southeastern coast (Tamil Nadu), it generally leaves the north-western parts dry as the winds blow from land to sea [c1][c2]. Therefore, the specific winter rainfall in the north-west is attributed to these westerly cyclonic systems.
Sources
- [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 30: Climatic Regions > The Cool, Dry Season (October To February) > p. 431
- [2] INDIA PHYSICAL ENVIRONMENT, Geography Class XI (NCERT 2025 ed.) > Chapter 4: Climate > Understanding the Monsoon > p. 33