The storm system is expected to intensify and become a very severe cyclone by 11:30 a.m. on Wednesday and make landfall between Karaikal and Mamallapuram around Puducherry late in the evening with windspeeds in the range of 120-130 km per hour, gusting to nearly 145 kmph.
 It is very likely to intensify further into a severe cyclonic storm during next 12 hours and into a very severe cyclonic storm during subsequent 12 hours.
Helpline numbers:
Cuddalore: The Cuddalore district administration has established control rooms at the District Collectorate (04142 220700/233933/221383/221113), Cuddalore Revenue Divisional Office (04142-231284), Chidambaram Sub-Collector Office (04144-222256/290037) and Vriddhachalam Sub-Collector Office (04143-260248).
Karaikal: Free helpline numbers – 1070/ 1077, Control Room – 04368 – 228801 227704, Whatsapp number – 99438 06263.
Perambalur: People in need of help can contact the helpline number 1077.
Tiruvarur: WhatsApp number 93453 36838. Toll free number 1077
Pudukottai: 1077 or 04322-222207
Here’s a list of helpline numbers of various depts
Chennai Corporation: 04425384530
24X7 control room: 1913
Flood control: 04424331074
Chennai MetroWater: 04428454040/04445674567
Ambulance service: 108/ 04428888105/ 7338895011
Electricity board
Chennai South-I: 9445850434/04424713988
Chennai South II: 9499050188/ 04423713631
Chengalpet: 9444099437/ 04427522119
Kancheepuram: 9445858740/ 04427282300
Chennai North: 9445850929/ 04428521833
Chennai Central: 9445449217/04428224423
Chennai West: 9445850500/04426151153
Here are the latest updates:
Thousands of police personnel deployed in coastal areas
Thousands of policemen, including commandos trained in disaster operations, have been deployed along the coastal areas as heavy rain lashed Chennai, Kancheepuram, Chengalpet, Tiruvallur and Cuddalore districts since Tuesday afternoon.
With meteorological experts warning that Cyclone Nivar, located 450 km southeast of Chennai, was likely to intensify further into a severe cyclonic storm in the next 24 hours, Director-General of Police J.K. Tripathy reviewed the deployment of manpower and infrastructure at the police headquarters.
Nellore, Prakasam administrations on tenterhooks
Authorities in south coastal Andhra Pradesh are on high alert as the cyclonic storm Nivar over southwest Bay of Bengal is likely to intensify into a severe cyclonic storm late on Wednesday.
Fishermen, who had ventured into the sea, rushed back as squally wind speed reaching 30 to 40 kmph prevailed. The fishermen started moving their boats to safer places as sea water advanced up to 100 metres in the coastal mandals, reminding them of the Laila cyclone that left a trial of destruction in 2010.
 Puducherry, Cuddalore gear up to deal with Cyclone Nivar
The Puducherry and Cuddalore district administrations are gearing up to deal with any eventuality arising out of Cyclone Nivar, which is expected to make landfall on Wednesday.
Nine teams of the National Disaster Response Force (NDRF) have been deployed in Puducherry, Cuddalore, Chidambaram, Parangipettai and Karaikal, to carry out relief and rescue operations.
 Severe cyclonic storm lay centered near Cuddalore
 Cyclonic storm Nivar intensified into a severe cyclonic storm and lay centred at 2330 hrs IST of 24th November, 2020 over southwest Bay of Bengal. It is about 310 km of Cuddalore. It is very likely to intensify further into a very severe cyclonic storm during next 12 hours.
cyclonic storm NIVAR intensified into a Severe Cyclonic Storm and lay centred at 2330 hrs IST of 24 th November, 2020 over southwest Bay of Bengal. It is about 310 km of Cuddalore. It is very likely to intensify further into a very severe cyclonic storm during next 12 hours. pic.twitter.com/k7cgd4cJPb
— India Meteorological Department (@Indiametdept) November 24, 2020
Chennai | November 25, 2020, 12.15 am
Heavy rainfall in Chennai
 Heavy rainfall recorded in Chennai from 0830 hours IST to 2030 hours IST of November 24, 2020: Nungambakkam: 106 mm Meenambakkam: 94 mm