A deep depression formed over the south-east Bay of Bengal has concentrated into a severe cyclonic storm and it now lies centred about 600 km south-east of Chennai coast.
Hyderabad Meteorological Centre Director Dr C V V Bhadram said: "We are expecting the storm to intensify further and move in a north-westerly direction towards north Tamil Nadu and south coastal Andhra Pradesh. We have already sounded an alert in these areas."
Rainfall, very heavy to heavy, is likely at Nellore, Prakasam, Guntur and Krishna districts in Andhra Pradesh and Chennai, Tiruvallur, Kanchipuram, Villupuram and Cuddalore districts in Tamil Nadu.
The Union territory of Pondicherry is also likely to experience heavy rain.
Strong winds from north-easterly direction are likely to blow through south coastal Andhra Pradesh and north Tamil Nadu from Monday evening.
