Chennai, Nov 17 : The Meteorological Department has issued a red alert in Chennai, Kancheepuram, Tiruvalllur, and Chengalpattu districts on heavy rainfall following a low pressure on Wednesday and Thursday. The weather department predicted that low pressure was reaching the coast and this could lead to heavy rains in Chennai and adjoining districts till Thursday night. Weathermen said that rains could lash isolated areas in Chennai and adjoining districts and 20mm rainfall is expected on Wednesday and Thursday. The Meteorological Department has also reported that there will be squally weather with wind speed reaching 40kmph to 50kmph and could touch 60kmph for the two days. The low-pressure area with associated cyclonic circulation is over the Bay of Bengal and could reach the South Andhra Pradesh and North Tamil Nadu coast by November 18. Following heavy rains, waterlogging, and inundation in parts of Chennai and adjoining districts, several people were staying in relief camps and the Greater Chennai Corporation has been taking steps to relocate them back to their homes. However, around 848 people are still staying in relief camps. Even on Tuesday, 16 streets in nine locations of Chennai were flooded with water and water was being pumped out. According to a senior official with the Greater Chennai Corporation, 426 pumps were used for flushing out water. The Rangarajapuram subway was flooded and closed and traffic was diverted and Greater Chennai Corporation officials were gearing up to prepare themselves for the red alert warning. /IANS