Chennai is still recovering from the heavy pounding it received by the rainfall, which started on Saturday. The continuous downpour for 24 hours led to inundation of most areas on Sunday and opening up of sluice gates of three city reservoirs to let out surplus water.

This is the heaviest rainfall on record since 2015 and has been caused by the northeast monsoon, which has been impacted by continued La Nina, a complex weather pattern caused by variations in ocean temperatures in the equatorial band of the Pacific Ocean. News agency PTI quoted Tamil Nadu’s revenue and disaster management minister KKSSR Ramachandran as saying that four people have died in rain related incidents and one person has been injured.

Also Read | Weather conditions not climate change responsible for Chennai rains, say experts

Though the rainfall stopped in Chennai late on Sunday night, mild to moderate, intermittent rainfall is continuing reported in other regions of Tamil Nadu, including Erode and Tiruvarur.

Since the start of the Northeast monsoon in October, Tamil Nadu and Puducherry regions have experienced about 43 per cent excess rainfall.

Here are the latest developments:

• The National Disaster Management Authority (NDRF) has pre-deployed four of its teams in Tamil Nadu on state government’s request. While one team each has been deployed in Thiruvallur and Chengalpattu district, two others are in Madurai district.

• Prime Minister Narendra Modi on Sunday spoke to Tamil Nadu chief minister MK Stalin and assured him of all possible support from the Centre in rescue and relief work. “Spoke to Tamil Nadu CM, Thiru @mkstalin and discussed the situation in the wake of heavy rainfall in parts of the state. Assured all possible support from the Centre in rescue and relief work. I pray for everyone’s well-being and safety.”

•In 24 hours (from Saturday 8.30am to Sunday morning), Chennai received 210mm of rainfall, according to the Regional Meteorological Centre (RMC). The Indian Meteorological Department (IMD) has predicted heavy rain in Chennai till Tuesday. It said a cyclonic circulation lies over north coastal Tamil Nadu, southeast of Bay of Bengal, and a low pressure area is likely to form by November 9.

• Several parts of Tamil Nadu capital reported extensive waterlogging on Sunday morning after the city recorded heavy overnight rains. Many vehicles were stranded and people had to wade through knee-deep water; some of the residents even complained of water entering their houses.

• Stalin inspected several inundated areas along with top officials, including chief secretary V Irai Anbu, and directed authorities to take swift action to drain the flood water.

• The state government has declared holiday for schools and colleges in Chennai, Tiruvallur, Kancheepuram and Chengalpet districts on November 8 and 9.

• Eleven districts – Chennai, Karur, Thiruvallur, Pudukottai, Sivagangai, Trichy, Namakkal, Ramanathapuram, Madurai, Virudhunagar and Erode – received more than 200 mm of rain in a 24-hour timespan.

• Some flight operations were affected, but no major disruption was reported in services. News agency PTI reported that airport authorities allowed passengers who arrived late due to heavy rainfall to board their flights.

• People were evacuated in inflatable boats by disaster response teams from some of the suburban areas. Most city and peripheral roads were inundated and several trees uprooted, leading to traffic diversions and disruption in transport services. At least six subways were closed for traffic.

• On November 6, 2015, Chennai received 246.5mm of rainfall on a single day – which was the highest in the last 10 years for the month of November. In the same month in 2017 and 2020, the city recorded 182.7mm and 161.8mm of rainfall.