India gets southwest monsoon winds in the summers and northeast monsoons during the winters. The former arise because of the formation of intense low-pressure system over the Tibetan Plateau. The latter arise due to the high pressure cells that are formed over the Siberian and Tibetan plateaus.

Southwest monsoon-

Cause: Intense low-pressure formation over the Tibetan Plateau because of intense heating during the summer season; permanent high pressure cell in the South of the Indian Ocean (East to Northeast of Madagascar in summer).

SW monsoon winds bring heavy rainfall to most parts of the country.

Factors influencing onset of SW monsoons-

1. Intense low-pressure formation over the Tibetan Plateau
2. Permanent high pressure cell in the South of the Indian Ocean
3. Subtropical jet stream
4. African Easterly jet (Tropical easterly jet)
5. Inter-Tropical Convergence Zone (ITCZ)

Factors influencing intensity of SW monsoons-

1. Strengths of the low pressure over Tibetan plateau and the high pressure over the south Indian Ocean
2. Somali Jet
3. Somali Current
4. Indian Ocean dipole
5. Indian Ocean branch of the Walker Cell

Northeast monsoon-

Cause: High pressure cells over the Tibetan and the Siberian Plateaus

NE monsoon winds bring rainfall to the southeast coast of the country (Tamil Nadu coast and Seemandhra’s south coast).

Factors responsible for the formation of the NE Monsoons-

1. Formation and strengths of the high pressure cells over the Tibetan and the Siberian Plateaus during winters
2. Migration of the Inter-Tropical Convergence Zone (ITCZ) to south of India
3. The high pressure cells in the southern Indian Ocean migrating to the west and weakening