Heavy rains lashed the Chennai on Thursday and more rain is expected in the coming days.
Due to low pressure that formed near Sri Lanka lay extended along the coast from southern Tamil Nadu to Andhra Pradesh, said Met department officials.
"However, as of now we don`t know if this trough will turn into a cyclone. A cyclone forms if a low pressure area develops. This will turn into a depression and then into a cyclone," an official said.