Correct option is D
The correct answer is: (D) Western disturbances
Explanation:
Western disturbances are extratropical storms originating in the Mediterranean region that bring light to moderate winter rainfall to the northern plains of India, especially Punjab, Haryana, Delhi, and western Uttar Pradesh.
These disturbances travel eastward and enter India via Pakistan and Afghanistan, significantly impacting Rabi crop irrigation (e.g., wheat).
Information Booster:
Western disturbances occur mainly during December to February.
They often bring snowfall in the Western Himalayas and rainfall in the northwestern plains.
These are low-pressure systems carried by westerly jet streams.
The rainfall is crucial for Rabi crops, but can sometimes cause cold waves or hailstorms.
They are called “disturbances” because they disturb the normal weather pattern.
Additional Information:
Easterlies – These are trade winds, blowing from east to west in the tropics; they do not bring winter rain.
Norwesters – Pre-monsoon violent thunderstorms occurring in eastern India (Bihar, Bengal, Assam) during summer, not in winter.
Bay of Bengal cyclones – These usually occur during post-monsoon and pre-monsoon periods and impact eastern coast, not northern plains.