Chennai, November 22: The low pressure area over Bay of Bengal has become well marked and is likely to concentrate into a depression and intensify into a cyclonic storm and cross Tamil Nadu and Puducherry coasts on November 25 bringing heavy rains, the Met department said on Sunday.

Under its influence, on November 25, Tamil Nadu, Puducherry and Karikkal regions are likely to witness rainfall at most places with heavy to very heavy showers at a few places and extremely heavy rains at isolated places.

Sea condition would be rough and wind speed is likely to gradually increase from Sunday onwards, "gusting 100 kmph over southwest Bay of Bengal and along and off Tamil Nadu and Puducherry coasts around the region of landfall on November 25," a bulletin said. Amphan Cyclone Concentrates Into a Depression Near Paradip in Odisha, to Intensify Into Severe Cyclonic Storm During Next 24 Hours.

Fishermen have been advised to stay off the sea and local authorities said they have also advised fishermen who have already set out for fishing to return. The rainfall activity is likely to increase over south peninsular India from November 23 onwards with fairly widespread showers and thunderstorm activity over Tamil Nadu, Puducherry and Karikkal regions between 24 and 26 November.

The bulletin said: "The low pressure area over southwest and adjoining southeast Bay of Bengal has become well marked low pressure area and persists over the same region.

It is very likely to concentrate into a depression over southwest Bay of Bengal during the next 24 hours and intensify further into a cyclonic storm during subsequent 24 hours. It is very likely to mover northwestwards and cross Tamil Nadu and Puducherry coasts between Karaikal and Mahabalipuram around 25 November 2020 noon/afternoon."

South coastal Andhra Pradesh, Rayalaseema and Telangana are also expected to receive rainfall from 25 to 26 November in view of the system, the bulletin said.