Chennai, Oct 13 (Reporter) The Northeast Monsoon rainfall activity is likely to commence over south eastern peninsular India,including Tamil Nadu, in the next two days and the IMD has forecast heavy rains and issued Orange alert for Chennai and other districts. The IMD on Sunday said the Northeast Monsoon will commence around October 15-16 with the two systems over the Bay is likely to intensify, promising heavy rains. The Well marked Low Pressure area over eastcentral Arabian sea is likely to move westnorthwestwards and intensify into a Depression over central Arabian Sea during the next 12 hours. A Low Pressure area is likely to form over central parts of south Bay of Bengal tomorrow (October 14) and heavy rains has been predicted and an Orange alert has been issued for Chennai and its neighbouring districts on October 15-16. As the system is likely to move towards North Tamil Nadu, the State government, which had been holding periodic review meetings, has geared up its machinery. Under its Isolated very heavy to extremely heavy rainfall is likely over Tamil Nadu and Andhra Pradesh during October 15 to 17. Chennai is expected to receive up to 22 cms of rain and Deputy Chief Minister Udhayanidhi Stalin today inspected the precautionary arrangements put in place, including deployment of NDRF and SDRF personnel, who were kept in a state of readiness to meet any exigency. Mr Udhayanidhi announced that helplines were opened and the Modern Control Room here will function round the clock with four shifts. Relief Centres will all basic amenities were also readied to house people evacuated from low-lying areas. The IMD said conditions are favourable for further withdrawal of Southwest Monsoon from remaining parts of the country and north Bay of Bengal during next 2 days. Simultaneously with the setting in of easterly and northeasterly winds over southern peninsular India, south and adjoining central Bay of Bengal, the Northeast Monsoon rainfall activity is like to commence during the same period. The Well Marked Low pressure area over eastcentral and adjoining westcentral Arabian sea persisted over the same region at 0830 hours of today. It is likely to move west-northwestwards and intensify into a Depression over central Arabian Sea during next 12 hours. The upper air cyclonic circulation over southwest Bay of Bengal now lies over north interior Tamil Nadu in lower tropospheric levels tilting southwestward with height. A trough runs from centre of the Well Marked Low pressure area over eastcentral and adjoining westcentral Arabian sea to Comorin area across south Kerala and the cyclonic circulation over Tamil Nadu in low to mid tropospheric levels. The cyclonic circulation over southeast Bay of Bengal and adjoining equatorial Indian Ocean moved westnorthwestwards and lay over southeast Bay of Bengal and extending upto 5.8 km above mean sea level at 0830 hours today. Under its influence, a low pressure area is likely to form over central parts of south Bay of Bengal tomorrow. It is likely to become Well marked low pressure area and move westnorthwestwards towards North Tamil Nadu, Puducherry and adjoining south Andhra Pradesh coasts during subsequent 48 hours. Fairly widespread to widespread light to moderate rainfall very likely over Tamil Nadu, Puducherry and Karaikal till October 17. Heavy to very Heavy rainfall occurred at isolated places over Tamil Nadu, Puducherry and Karaikal during the last 24 hrs, with Madurai recording 16 cms of rains and other southern districts receiving good rainfall...////...