New Delhi, Nov 9 : Light to moderate rainfall is expected in most places, heavy showers in few, and extremely heavy rainfall in isolated places over coastal Tamil Nadu, while heavy to very heavy showers likely to occue over isolated places in south coastal areas of Andhra Pradesh on Wednesday, the IMD said. Tamil Nadu and coastal Andhra Pradesh are already being battered by rain leading to flooding in many areas. "Under the influence of a cyclonic circulation over southeast Bay of Bengal and neighbourhood, a low pressure area formed over the same region at 8.30 a.m. It is likely to concentrate into a depression over southwest and adjoining southeast Bay of Bengal during the next 36 hours," the India Meteorological Department (IMD) said. The system is likely to move west-northwestwards and reach near north Tamil Nadu coast by Thursday morning and in association with this formation, there would be a continuation of the ongoing active rain spell in the state till November 11. Therefore, coastal Tamil Nadu and south coastal Andhra Pradesh is likely to experience light to moderate rainfall in most places with heavy to very heavy rainfall and extremely heavy showers in isolated places on November 11 too. November 12 will see light to moderate rainfall in most places with cloudburst very likely in isolated places in Tamil Nadu, the IMD said. Squally winds with speed reaching 40-50 kmph gusting to 60 kmph are likely to prevail over southeast Bay of Bengal on Wednesday, it added. Sea condition will be rough to very rough over southeast Bay of Bengal on Wednesday, southwest Bay of Bengal on Wednesday and Thursday, and off Tamil Nadu and adjoining south Andhra Pradesh coasts on Thursday. The IMD has warned the fishermen to not venture into the southeast Bay of Bengal on Wednesday and southwest Bay of Bengal, off Tamil Nadu and adjoining south Andhra Pradesh coasts, till Thursday. /IANS