In the western part of Madhya Pradesh, rainfall is mostly received from

Concept

India’s rainy season is dominated by the southwest monsoon (June–September), which advances across the seas around the peninsula as two branches: the Arabian Sea branch, which moves north-east across the west coast, Gujarat, and the western and central parts of the subcontinent; and the Bay of Bengal branch, which moves north-west across the eastern coast, West Bengal, and Odisha before curving into the Gangetic plains and the Himalayan foothills. Which branch dominates a given location’s monsoon rainfall depends on which one reaches it first and more directly, given the location’s position relative to the Arabian Sea and the Bay of Bengal.

Application

Madhya Pradesh lies in central India and receives rain from both monsoon branches, but the two halves of the state are not served equally:

• The western part of MP (districts such as Ratlam, Mandsaur, Ujjain, Indore) sits closer to the Arabian Sea coast (Gujarat/Maharashtra) and lies in the more direct path of the Arabian Sea branch, which is the dominant source of its monsoon rainfall.

• The eastern part of MP (districts such as Balaghat, Mandla, Shahdol) is farther from the Arabian Sea but lies in the path of the Bay of Bengal branch after it curves west-north-west through Odisha and Chhattisgarh, making that branch dominant there.

Since the question specifically asks about the western part of Madhya Pradesh, the governing branch is the Arabian Sea branch of the southwest monsoon.

Cross-check

Tropical cyclones and winter showers are both real Indian weather phenomena, but neither is the dominant rainfall source for interior, monsoon-fed Madhya Pradesh: cyclones mainly affect the coastal tracts where they make landfall, well away from MP, and winter showers there (linked to western disturbances moving across north India) are a minor, occasional addition compared with the southwest monsoon season, which supplies the bulk of the state’s annual rainfall. This confirms the Arabian Sea branch as the correct answer for western Madhya Pradesh.