WMO El Niño/La Niña Updates
Latest WMO El Niño/La Niña Update (November 2024)
As of end-November 2024, oceanic and atmospheric observations continue to reflect ENSO-neutral conditions (i.e., neither El Niño nor La Niña), with sea surface temperatures slightly below average over much of the central to eastern equatorial Pacific. Cold subsurface temperature anomalies have persisted east of the International Dateline since May 2024. However, this cooling has not yet translated into cold sea surface temperatures typical of La Niña thresholds. One possible reason for this slow development is the strong westerly wind anomalies observed for much of the time from September to early November 2024, which are not conducive for La Niña development. The overlying atmospheric conditions, including surface and upper-level winds as well as patterns of cloudiness and rainfall, remain consistent with ENSO-neutral conditions. The Southern Oscillation Index (SOI), defined as the standardized Tahiti minus Darwin sea-level pressure difference, remained within the ENSO-neutral range during September and October 2024. Cloudiness near the equatorial International Date Line is below average, with enhanced convection and precipitation over Indonesia. Overall, observed oceanic and atmospheric conditions indicate ENSO-neutral conditions.
Using the recent observations as the starting point for their dynamical seasonal prediction systems, the WMO Global Producing Centres of Seasonal Prediction routinely issue global-scale climate forecasts for the coming months. Their latest forecasts and expert assessments suggest a moderate probability (about 55%) of La Niña conditions developing in the central to eastern equatorial Pacific from December 2024 to February 2025 and from January to March 2025, while the chances of ENSO-neutral conditions are estimated at 45% for the same periods. Should La Nina develop, as is slightly favored by predictions, it is expected to be a short-lived event: the chance of La Niña during February-April 2025 decreasing to around 45%, and ENSO-neutral conditions becoming dominant at 55%. The chance of El Niño developing during this entire forecast period is negligible.
It is important to note that El Niño and La Niña are not the only factors that drive global and regional climate patterns, and further that the magnitudes of ENSO indicators do not directly correspond to the magnitudes of their effects. At the regional level, seasonal outlooks need to assess the relative effects of both the ENSO state and other locally relevant climate drivers. Regionally and locally applicable information is made available via regional and national seasonal climate outlooks, such as those produced by WMO Regional Climate Centres (RCCs), Regional Climate Outlook Forums (RCOFs) and National Meteorological and Hydrological Services (NMHSs).
National Meteorological and Hydrological Services (NMHSs) will closely monitor changes in the state of ENSO over the coming months and provide updated outlooks, as needed. Read more >>
An archive of all WMO El Niño/La Niña Updates issued so far, is available here below:
El Niño/La Niña Background
 |  |
Research conducted over recent decades has shed considerable light on the important role played by interactions between the atmosphere and ocean in the tropical belt of the Pacific Ocean in altering global weather and climate patterns. During El Niño events, for example, sea temperatures at the surface in the central and eastern tropical Pacific Ocean become substantially higher than normal. In contrast, during La Niña events, the sea surface temperatures in these regions become lower than normal. These temperature changes are strongly linked to major climate fluctuations around the globe and, once initiated, such events can last for 12 months or more. The strong El Niño event of 1997-1998 was followed by a prolonged La Niña phase that extended from mid-1998 to early 2001. El Niño/La Niña events change the likelihood of particular climate patterns around the globe, but the outcomes of each event are never exactly the same. Furthermore, while there is generally a relationship between the global impacts of an El Niño/La Niña event and its intensity, there is always potential for an event to generate serious impacts in some regions irrespective of its intensity.
Forecasting and Monitoring the El Niño/La Niña Phenomenon
The forecasting of Pacific Ocean developments is undertaken in a number of ways. Complex dynamical models project the evolution of the tropical Pacific Ocean from its currently observed state. Statistical forecast models can also capture some of the precursors of such developments. Expert analysis of the current situation adds further value, especially in interpreting the implications of the evolving situation below the ocean surface. All forecast methods try to incorporate the effects of ocean-atmosphere interactions within the climate system.
The meteorological and oceanographic data that allow El Niño and La Niña episodes to be monitored and forecast are drawn from national and international observing systems. The exchange and processing of the data are carried out under programmes coordinated by the World Meteorological Organization.
WMO El Niño/La Niña Update
WMO El Niño/La Niña Update is prepared on a quasi-regular basis (approximately once in three months) through a collaborative effort between WMO and the International Research Institute for Climate and Society (IRI) as a contribution to the United Nations Inter-Agency Task Force on Natural Disaster Reduction. It is based on contributions from the leading centres around the world dealing with this phenomenon. The contributors include:
- African Centre of Meteorological Application for Development (ACMAD)
- Asia-Pacific Economic Cooperation (APEC) Climate Centre (APCC)
- Australian Bureau of Meteorology (BoM)
- Australian Centre for Sustainable Catchments of the University of Southern Queensland
- Badan Meteorologi Klimatologi dan Geofisika (BMKG) – the Meteorological, Climatological and Geophysical Agency of Indonesia
- Centro Internacional para la Investigación del Fenómeno El Niño (CIIFEN)
- China Meteorological Administration (CMA)
- Climate Prediction Center (CPC) and National Weather Service (NWS) of the National Oceanic and Atmospheric Administration (NOAA) of the United States of America
- Climate Variability and Predictability (CLIVAR) project of the World Climate Research Programme (WCRP)
- Comisión Permanente del Pacífico Sur (CPPS)
- Consortium for Capacity Building (CCB), University of Colorado, USA
- El Comité Multisectorial encargado del Estudio Nacional del Fenómeno El Niño (ENFEN) of Peru
- European Centre for Medium Range Weather Forecasts (ECMWF)
- Fiji Meteorological Service
- India Meteorological Department (IMD)
- Indian Institute of Science (IISc)
- IGAD (Inter Governmental Authority on Development) Climate Prediction and Applications Centre (ICPAC)
- Instituto Nacional de Meteorologia e Hidrologia (INAMHI) of Ecuador
- International Monsoons Project Office (IMPO)
- International Research Institute for Climate and Society (IRI)
- Japan Meteorological Agency (JMA)
- Korea Meteorological Administration (KMA)
- Mauritius Meteorological Services (MMS)
- Météo France
- Met Office in the United Kingdom (UKMO)
- National Center for Atmospheric Research (NCAR) of the United States of America
- National Institute of Water and Atmospheric Research (NIWA) of New Zealand
- Southern African Development Community Climate Services Centre (SADC-CSC)
- Tasmanian Institute of Agricultural Research (TIAR, a Joint Venture between the University of Tasmania and the Tasmanian Government, Australia)
Archive of WMO El Niño/La Niña Updates
The following is the archive of WMO El Niño/La Niña Updates, including the latest one, prepared through a collaborative effort between the WMO and the International Research Institute for Climate and Society (IRI) as a contribution to the United Nations Inter-Agency Task Force on Natural Disaster Reduction. They have been prepared based on contributions of many National Meteorological and Hydrological Services (NMHSs) and other agencies/experts. Please see each update for the specific contributions.