Sparing Tamil Nadu, the deep depression over Bay of Bengal has moved to Andhra Pradesh coast and is likely to intensify into a cyclonic storm by tomorrow, Met office said today.

The danger of heavy rainfall in excess of 25 CM in Chennai and neighbourhood, forecast last night, has abated with the weather system moving away but coastal areas of the state would continue to experience heavy rains for another 24 hours.

The meteorological department said the rainfall would gradually decrease in the state as the deep depression over the Bay of Bengal has moved toward Andhra Pradesh and lay centred about 170 km southeast of Nellore.

Meanwhile, several parts of Tamil Nadu and Puducherry continued to receive rains for the third day today.

Regional Meteorological Centre, Director, K Balachandran told reporters "due to the system moving away from Tamil Nadu, rainfall would decrease in a phased manner".

"We are expecting the deep depression to become a cyclone in the next 24-48 hours.", he said adding heavy rainfall may occur over North Tamil Nadu in one or two places during the period.

A met office bulletin said, "The system is likely to move north-northeastwards off Andhra Pradesh Coast and intensify into a cyclonic storm during the next 24 hours."

In the last 24 hours that ended at 8.30 am today, Kelambakkam on the outskirts of Chennai received the highest rainfall of 23 cm, Chennai 11 cm, Nungambakkam 8 cm and Anna Universiy 7.5 cm.

Acting on the Met office forecast last night, the Tamil Nadu government has ordered precautionery measures, including directing District Collectors to take all precautionary measures and advised senior civil servants to visit districts which are expected to receive heavy rainfall.

The government, which had received flak from opposition parties for its handling of the deluge here in December last, also has set up a call centre with the telephone number 1070 to receive rainfall related grievances.

National Disaster Response Force Teams from neighbouring Vellore, Arakkonam, were also put on standby in low lying areas as part of the precautionery measures.

Greater Chennai Corporation Commissioner B Chandra Mohan said officials have been deputed in all the Corporation zones specifically to monitor rain related relief measures.