‘Tamil Nadu must brace for heavy rainfall, storms, flood;’

Under normal conditions, sea surface temperatures in the equatorial Pacific Ocean remain around 27°C. When the sea surface temperature rises by about 4°C above the normal level due to climate change, the event is referred to as a Super El Nino.

Since this year is expected to be a Super El Nino year, there is a possibility of receiving more rainfall than during a normal El Nino year. Therefore, the government should initiate preparedness measures well in advance and ensure that the administration, disaster management agencies and the public are ready. Early preparedness and timely weather advisories can significantly reduce the impact of extreme weather events.

Between 1950 and 2025, Tamil Nadu experienced El Nino conditions on 21 occasions. The State recorded heavy rainfall during the El Nino years of 1979, 1984, 2014 and 2024. As this year is expected to be a Super El Nino year, advance preparedness becomes even more important.

During a Super El Nino, sea surface temperatures in the Pacific Ocean rise well above normal, weakening the trade winds. When these weakened winds interact with the northeast winds moving from the Tibetan region towards India, they can enhance low-pressure systems over the sea under favourable atmospheric conditions. This may provide additional energy to storms, increasing their potential impact. However, the actual intensity and behaviour of cyclones will depend on the prevailing weather conditions at that time.

The northern coastal districts of Tamil Nadu should receive special attention. Historically, cyclones that formed during El Nino years have affected coastal areas between Nagapattinam and Machilipatnam in Andhra Pradesh. Focusing preparedness efforts in these regions can help minimise damage. More importantly, accurate and timely weather information should be communicated to the public.

There is certainly a possibility of receiving higher rainfall during a Super El Nino. This could increase the risk of flooding, particularly in cities like Chennai. The city’s storm water drainage infrastructure is designed to handle around 200 mm of rainfall. If rainfall exceeds that level, floodwaters will take longer to recede. At the same time, rough sea conditions associated with low-pressure systems may prevent rainwater from draining efficiently into the sea, delaying floodwater discharge.

Countries must work together to reduce global warming and implement effective climate action immediately. Collective efforts are essential to reduce the frequency and severity of extreme weather events in the future.

Reducing carbon dioxide emissions is essential to slowing global warming. During El Nino events, excess carbon dioxide in the atmosphere traps heat, preventing it from escaping from the Pacific Ocean into space. This causes sea surface temperatures to rise further. To reduce this, countries around the world must take strong and immediate action to cut greenhouse gas emissions and mitigate climate change