A surge in the current wet spell in the southern states is expected with a depression forming over Bay of Bengal which is likely to intensify into a cyclonic storm, the weather office said on Sunday.
The depression lay centred 450 km east southeast of Chennai and is expected to turn into a cyclonic storm and cross the Tamil Nadu coast between Karaikal and Chennai by Monday night, an India Meteorological Department official said.
Under its influence, rainfall is expected in most parts of Tamil Nadu with heavy to very heavy rainfall over north coastal Tamil Nadu and Puducherry in the next 24-48 hours, the official said. Isolated heavy rainfall is also expected in south coastal Andhra Pradesh, south interior Karnataka and Kerala during the next 24-48 hours.
Fishermen in Tamil Nadu have been advised not to venture out to sea in the next 24 to 48 hours "as the sea will be rough to very rough", the official said.
The northeast monsoon, which has brought the wet spell, had set in over the southern region on 29 October.