Answer:

During the winter, the Western Disturbance is an extratropical storm that brings rain to North and Northwest India. Wheat and winter crops benefit greatly from it. It is influenced by westerly winds (westerlies are prevailing winds from the west toward the east in the middle latitudes between 30 and 60 degrees latitude.)

The Mediterranean Sea is the source of Western Disturbances. They take moisture from this region and the Atlantic Ocean and migrate eastward.

Frontogenesis (a process in which two air masses of differing densities come together to form a front) occurs in the extratropical zone, which aids in the creation of the cyclone. Extratropical cyclones are cyclones that form over a mid-latitude latitude. The journey as a family, one by one, to north India.

Because the westerlies are stronger in the winter, they occur more frequently. The trek through Iraq, Iran, Afghanistan, and Pakistan to reach India. In westerlies, it's mostly lower tropospheric systems that vary in strength and vertical extent due to the superimposition of a mid and upper tropospheric trough.