Southern districts of Tamil Nadu and Kerala are expected to witness moderate to heavy rainfall in the next 24 hours due to formation of cyclonic storm ‘Ockhi’ on Thursday, a MeT official said.

The storm could also intensify into severe cyclone, he said, adding the cyclone is expected to have a wind speed of 65-75 km per hour and that the sea will be rough.

Fishermen in coastal regions in southern Tamil Nadu including Kanyakumari, Tuticorin and Ramanathapuram districts have been advised not to venture into sea for the next 24 hours.

“Yesterdays’s depression escalated into deep depression early this morning and further intensified into cyclonic storm at 8.30 am and lies at about 70 km south of Kanyakumari,” Director, Regional Meteorological Centre, S Balachandran told reporters.

The depression on Wednesday hovered over South West Bay of Bengal.

The name Ockhi, given by Bangladesh, is expected to move further north-westward towards Lakshwadeep, he said.

As per current indications, “it is expected to intensify into severe cyclone also”.

Under the influence of the system, moderate rainfall is expected to occur all over southern Tamil Nadu and Puducherry, Balachandran said.

Southern Tamil Nadu districts including Kanyakumari, Tirunelveli and Tuticorin will experience heavy rainfall.

At one or two places of these regions, heavy to very heavy rainfall is expected as well, he added.

Also, some places in Theni, Dindigul, Nilgiris, Coimbatore and Delta regions, including Thanjavur may see heavy rainfall, he said.

In Chennai, a few intermittent spells of rainfall can be expected.

In Kerala, the official said all southern districts of the state will experience good rainfall during the next 24 hours.

Cyclone Ockhi, lashing parts of Tamil Nadu and Kerala with torrential rains and gusty winds, is approaching the Lakshadweep archipelago, a top official at the Ministry of Earth Sciences said in Delhi on Thursday.

Madhavan Rajeevan, secretary in the ministry, said the archipelago in the southern part of the Arabian Sea will start experiencing heavy rainfall and strong winds from Friday.

“It will hit the islands on December 2,” Rajeevan said.