Arabian sea branch :
The Arabian sea branch of the southwest monsoon first hits the western ghats of the coastal state of Kerala, thus making the area the first state in India to receive rain from the Southwest monsoon. This branch of the monsoon moves northwards along the western ghats with precipitation on coastal areas, west of the western ghats. The eastern areas of the western ghats do not receive much rain from this monsoon as the wind does not cross the western ghats.
Bay of Bengal branch :
The Bay of Bengal Branch of southwest monsoon flows over the bay of Bengal heading towards north - east India and Bengal, picking up more moisture from the Bay of Bengal. The winds arrive at the eastern Himalayas with large amounts of rain. After the arrival at the eastern Himalayas, the winds turns towards the west, travelling over the Indo- Gangetic plain at a rate of roughly 1-2 weeks per state pouring rain all along its way.