Weather experts are divided over the emergence of La Nina with the APEC Climate Center (APCC) predicting it to emerge in December. This is contrary to the forecast made by Australia’s Bureau of Meteorology (BoM), which has said chances are remote for the weather event to emerge by February. 

“Niño 3.4 index is expected to be – 0.9 °C  for December 2024 and gradually increase to -0.1 °C for April 2025. La Niña conditions are most probable (~65 per cent) for November 2024-January 2025, with a shift to ENSO-neutral conditions expected to be more probable (59 per cent) from February-April 2025,” the APCC said in its latest update.

Last week, BoM said chances of a La Niña event developing in the coming months had decreased compared to recent outlooks. “If a La Niña were to develop, it is forecast to be relatively weak (in terms of the strength of the sea surface temperature (SST) anomaly) and short-lived, with all models forecasting neutral values in February,” it said.

CPC pares chances

The Climate Prediction Center of the US, an arm of the National Oceanic and Atmospheric Administration (NOAA), recently reduced the chance of La Nina emerging during September-November to 60 per cent. In September, it said there was a 71 per cent chance of the weather event. 

It predicted the event to persist through January-March 2025. “The (CPC) team still favours a weak event, but has lowered the chances of La Niña. A weaker La Niña implies that it would be less likely to result in conventional winter impacts, though predictable signals could still influence the forecast guidance,” the US weather agency said. 

Earlier this month, the India Meteorological Department predicted a higher probability of La Niña conditions developing during the post-monsoon season, 2024.

Above-normal global temperature

APCC predicted  a “strongly enhanced probability” for above-normal temperatures for most of the globe except for the central and eastern tropical and subtropical Pacific between November 2024 and April 2025.

It predicted above-normal temperatures in the Indian Ocean region — excluding the southern region — the Arctic, Pacific (excluding central and eastern tropical region), Atlantic, South-East Asia, Central and South America and southern Africa.

For South Asia, particularly India, APCC has forecast a 80 per cent chance of above-normal temperature during November 2024-April 2025 and a 37.4 per cent probability of above-normal rainfall. It has given another 35.3 per cent chance of a near-normal rainfall in the region during the period.