La Nina conditions may develop by year-end: WMO

There is a 60 percent chance of La Nina conditions emerging towards the end of this year, which is associated with colder-than-usual winters in northern parts of the country.

The latest update from the World Meteorological Organization Global Producing Centres of Long-Range Forecasts on Wednesday, 11 September indicate a 55 per cent likelihood of a transition from the current neutral conditions (neither El Nino nor La Nina) to La Nina conditions during September-November 2024.

"This likelihood increases to 60 per cent from October 2024 to February 2025, with the chance of El Nino redeveloping during this time being negligible," the WMO said.

La Nina refers to the large-scale cooling of the ocean surface temperatures in the central and eastern equatorial Pacific Ocean, coupled with changes in the tropical atmospheric circulation, such as winds, pressure and rainfall.

It is generally associated with intense and prolonged rains during the monsoon season in India and colder-than-usual winters, particularly in northern regions.

However, the India Meteorological Department is yet to confirm if La Nina conditions will lead to colder-than-usual winters.

The effects of each La Nina event vary depending on its intensity, duration, time of year it develops, and the interaction with other climate drivers. Generally, La Nina produces the opposite climate impacts to El Nino, especially in tropical regions.

However, naturally occurring climate events such as La Nina and El Nino events are taking place in the broader context of human-induced climate change, which is increasing global temperatures, exacerbating extreme weather and climate, and impacting seasonal rainfall and temperature patterns, the WMO said.

WMO Secretary-General Celeste Saulo said: "Since June 2023, we have seen an extended streak of exceptional global land and sea surface temperature. Even if a short-term cooling La Niña event does emerge, it will not change the long-term trajectory of rising global temperatures due to heat-trapping greenhouse gases in the atmosphere."

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

The 2023-24 El Nino event started emerging in June 2023 and peaked in November 2023 - January 2024 as one of the five strongest on record before dissipating – although some impacts continued.

For the past three months, neutral conditions have prevailed – neither El Nino nor La Nina.