Mid Level Circulation is present in South Bay of Bengal. This would move Northwest towards South AP, North TN coast around 20/5. Southwest monsoon would make onset in Kerala around 20/5 to 24/5/25. Continued Continuation Due to this interior TN can expect good thunderstorms rain from 17/5 to 20/5/25. North Coastal. TN&Puducherry can expect Light Rain from 17/5 to 20/5, moderate rain from 21/5 to 25/5 including Chennai. Kerala can expect good monsoon rain from 20/5. Pic Tropic Ssec