The depression over Bay of Bengal intensified into a deep depression and lay about 750 kilometres off Chennai on Wednesday, and it would develop into a cyclonic storm influencing moderate to heavy rainfall in Tamil Nadu and Puducherry, the India Meteorological Department (IMD) said.

The well-marked low pressure area over southeast Bay of Bengal intensified into a depression on December 6 evening over the same region and further intensified into a deep depression, and lay about 750 km east-southeast of Chennai, the IMD said in a bulletin.

It is very likely to move west-northwestwards and intensify gradually into a cyclonic storm on Wednesday evening and reach southwest Bay of Bengal, off north Tamil Nadu-Puducherry and adjoining south Andhra Pradesh coasts by the morning of December 8.

Under its influence, light to moderate rainfall at most places and heavy to very heavy showers at isolated places is very likely over coastal Tamil Nadu, Puducherry, Karaikal, southern Andhra Pradesh and Rayalaseema between December 8 and 10.

The cyclonic storm is expected to make landfall between Puducherry and Sriharikota (Andhra Pradesh) by December 10, according to the bulletin.

"Squally wind, speed reaching 50-60 kmph gusting to 70 kmph, is likely to prevail over southeast Bay of Bengal during next 24 hours and then reduce to 40-45 kmph gusting to 55 kmph on Dec 8," the bulletin stated.

The cyclone has been named Mandous which has been given by United Arab Emirates (UAE). In Arabic, Mandous means ‘treasure box’. Notably, after Sitarang that had hit Bangladesh this October, it will be the second cyclone generated in Bay of Bengal in the post-monsoon season.

The Tamil Nadu government has made all precautionary measures in light of the forecast for heavy rainfall and an expected cyclone.?