The series of LOW in Indian Ocean and adjoining Ocean is the result of weak westerly originating from
south Indian Ocean pressure system.
The TMD chart is showing that.
It is further withdrawal of SWM from below 8 Degree North i.e further SOUTH below INDIAN MAINLAND MASS.[KANYAKUMARI]
This make EAST-WEST trough (in weak westerlies)which is the origin of rainfall in TN
The usual strengthening of HIGH PRESSURE system over Asia (Siberia & neighborhood and the Tibetan HIGH at 5000m high.) is to follow to enhance NEly in TN