El Nino ending; at least 60% chance of La Nina developing during July-Sept: WMO

New Delhi: The 2023-24 El-Nino event, which drove record-breaking temperatures and extreme weather around the world, is predicted to transition to La-Nina conditions later this year, according to a new update from the World Meteorological Organization (WMO).

The world experienced the warmest April ever and the 11th consecutive month of record-high temperatures this year. Sea-surface temperatures have been record-high for the last 13 months, according to the WMO.

The WMO said this is happening due to the naturally-occurring El Nino -- unusual warming of waters in the central and eastern Pacific Ocean -- and the additional energy trapped in the atmosphere and ocean by greenhouse gases from human activities.

Amid a prevailing but weakening El Nino, millions of people in South Asia, including India and Pakistan, endured brutal heat in April and May.

The latest forecasts from the WMO Global Producing Centres of Long-Range Forecasts give equal chances (50 per cent) to either neutral conditions or a transition to La Nina during June-August.

The chance of La-Nina conditions increases to 60 per cent during July to September and 70 per cent during August to November.

The probability of El Nino redeveloping is negligible during this time, the WMO said.

While El Nino is associated with weaker monsoon winds and drier conditions in India, La Nina -- the antithesis of El Nino -- leads to plentiful rainfall during the monsoon.

Last month, the India Meteorological Department (IMD) had forecast above-normal rain in the monsoon season in India, with favourable La-Nina conditions expected to set in by August-September.

Monsoon is critical for India's agricultural landscape, with 52 per cent of the net cultivated area relying on it. It is also crucial for replenishing reservoirs critical for drinking water, apart from power generation across the country.

"Every month since June 2023 has set a new temperature record and 2023 was by far the warmest year on record. The end of El Nino does not mean a pause in long-term climate change as our planet will continue to warm due to heat-trapping greenhouse gases. Exceptionally high sea-surface temperatures will continue to play an important role during the next months," WMO Deputy Secretary-General Ko Barrett said.

The last nine years have been the warmest on record even with the cooling influence of a multi-year La Nina from 2020 to early 2023.

El Nino peaked in December 2023 as one of the five strongest on record.

"Our weather will continue to be more extreme because of the extra heat and moisture in our atmosphere. This is why the 'Early Warnings for All' initiative remains the WMO's top priority. Seasonal forecasts for El Nino and La Nina and the anticipated impacts on the climate patterns globally are an important tool to inform early warnings and early action," said Barrett, who is leading a WMO delegation at the UN Climate Change session in Germany's Bonn.

La-Nina conditions generally follow strong El-Nino events, and this is in line with recent model predictions, although high uncertainty remains regarding its strength or duration.

According to the WMO, above-normal sea-surface temperatures in all areas are expected to persist outside the near-equatorial eastern Pacific Ocean.

There is, therefore, widespread prediction of above-normal temperatures over almost all land areas.