WMO Forecasts Potential Weak and Short-Lived La Niña Amid Global Climate Extremes

“The year 2024 started with an El Niño and is poised to become the hottest year on record,” said WMO Secretary-General Celeste Saulo.

 The World Meteorological Organization (WMO) has reported a 55% likelihood of La Niña conditions developing between December 2024 and February 2025. However, these conditions are expected to be relatively weak and short-lived, with ENSO-neutral conditions likely to return by February-April 2025.

La Niña is characterized by the cooling of sea surface temperatures in the central and eastern equatorial Pacific Ocean, accompanied by shifts in atmospheric circulation, such as winds, rainfall, and pressure patterns. Its impacts are generally opposite to those of El Niño, often influencing tropical regions with drier or wetter conditions.

The broader backdrop to this potential La Niña development is human-induced climate change, which is intensifying global temperatures, extreme weather patterns, and seasonal rainfall variability. Despite the potential cooling influence of a weak La Niña, its effects are unlikely to counteract the warming caused by record levels of greenhouse gases in the atmosphere.

“The year 2024 started with an El Niño and is poised to become the hottest year on record,” said WMO Secretary-General Celeste Saulo. “Even if La Niña develops, its cooling impact will be insufficient to offset the warming driven by human activities. The extreme weather events we’ve witnessed this year, from record rainfall to devastating flooding, are the new norm in our changing climate.”

Current ENSO Conditions and Indicators

As of late November 2024, oceanic and atmospheric indicators show ENSO-neutral conditions, persisting since May. Slightly below-average sea surface temperatures have been recorded in the central to eastern equatorial Pacific, but these remain below the thresholds typically associated with La Niña.

The delayed emergence of La Niña may be attributed to strong westerly wind anomalies observed between September and early November, which are unfavourable for its development. Earlier WMO forecasts in September predicted a 60% likelihood of La Niña forming in December-February, but updated observations have slightly tempered these expectations.

The Importance of Seasonal Forecasts

Seasonal forecasts for phenomena like La Niña and El Niño are critical tools for anticipating global climate impacts, informing early warning systems, and guiding climate adaptation strategies. These forecasts are especially valuable in tropical regions, where ENSO events significantly influence seasonal rainfall and temperature patterns.

Preparedness in a Changing Climate

Even without the presence of El Niño or La Niña since May 2024, the world has experienced extreme weather events, further underscoring the need for robust early warning systems and climate adaptation efforts.

“Early warnings must be paired with early action to mitigate the human and economic toll of these climate events,” added Saulo.

The WMO continues to monitor oceanic and atmospheric conditions closely, providing regular updates to ensure that governments and communities are prepared for the potential impacts of climate variability amid the broader challenges posed by global warming.