WMO Update: El Niño Waning as La Niña Conditions Loom, Heightened Climate Vigilance Essential

The update predicts a likely transition to La Niña conditions later this year, with a 60% chance during July-September and 70% during August-November.

The World Meteorological Organization (WMO) has released a new update indicating that the 2023/24 El Niño event, which has significantly contributed to rising global temperatures and extreme weather, is showing signs of ending. The update predicts a likely transition to La Niña conditions later this year, with a 60% chance during July-September and 70% during August-November.

Key Messages:

The 2023/24 El Niño event is showing signs of ending.

WMO predicts at least a 60% chance of La Niña during July-September.

Average global sea surface temperatures remain exceptionally high.

Seasonal forecasts are vital for early warnings and proactive measures.

La Niña, characterized by large-scale cooling of ocean surface temperatures in the central and eastern equatorial Pacific Ocean, brings significant changes in tropical atmospheric circulation, affecting winds, pressure, and rainfall. The impacts of La Niña vary based on its intensity, duration, and interaction with other climate variability modes.

Despite the natural occurrence of the El Niño Southern Oscillation (ENSO), these events now occur against the backdrop of human-induced climate change, which continues to drive global temperatures higher and exacerbate extreme weather patterns.

WMO Deputy Secretary-General Ko Barrett stated: "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 Niño does not signal 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 a crucial role in the coming months."

The past nine years have been the warmest on record, even with the cooling influence of a multi-year La Niña from 2020 to early 2023. El Niño peaked in December 2023 as one of the five strongest on record.

Ko Barrett added: "Our weather will continue to be more extreme due to the additional heat and moisture in our atmosphere. This underscores the importance of the Early Warnings for All initiative, which remains WMO's top priority. Seasonal forecasts for El Niño and La Niña and their anticipated global climate impacts are vital tools for early warnings and early action."

Forecast and Predictions: The latest forecasts from WMO Global Producing Centres of Long-Range Forecasts indicate equal chances (50%) of either neutral conditions or a transition to La Niña during June-August 2024, with the likelihood of La Niña increasing to 60% during July-September and 70% during August-November. The chance of El Niño redeveloping during this period is negligible.

Global Seasonal Climate Update: The Global Seasonal Climate Update (GSCU) incorporates influences from other major climate variability modes, such as the North Atlantic Oscillation, the Arctic Oscillation, and the Indian Ocean Dipole. The latest GSCU predicts widespread above-normal sea surface temperatures outside the near-equatorial eastern Pacific Ocean and anticipates above-normal temperatures over nearly all land areas.

Rainfall predictions align with early-stage La Niña conditions, indicating above-normal rainfall in far northern South America, Central America, the Caribbean, the northern Greater Horn of Africa, the Sahel, parts of southwest Asia, and the central Maritime Continent.

WMO's updates, based on Global Producing Centres of Long-Range Forecasts, provide crucial information to governments, the United Nations, decision-makers, and stakeholders in climate-sensitive sectors to mobilize preparations and protect lives and livelihoods.

WMO Regional Climate Centres and National Meteorological and Hydrological Services (NMHSs) will continue to monitor ENSO changes closely in the coming months.