La World Meteorological Organization (WMO) has focused on the possible return of the La NiƱa phenomenon during the upcoming Northern Hemisphere winter, albeit in a rather weaker form. The new forecasts, released by this UN agency, indicate that the cooling of the Pacific will not be enough to halt a global context marked by warming and episodes of extreme weather.
According to the latest seasonal bulletin, the WMO estimates that there are around a 55% probability that a La NiƱa episode may develop between December and February. This scenario, even if moderate, could affect the temperature and precipitation patterns on a planetary scale during the coming months, with implications for agriculture, energy and risk management, also in Europe and in Spain.
What does a weak La NiƱa mean and how does it affect the global climate?
La NiƱa is characterized by a anomalous cooling of surface waters of the central and eastern Pacific. On this occasion, the WMO speaks of a weak episode because the oceanic and atmospheric indicators only show ālimiting conditionsāThat is, values āāclose to the thresholds that officially define this phase of the ENSO cycle (El NiƱo-Southern Oscillation).
The first signs began to be detected mid novemberThis occurred when measurements in the Pacific pointed to an incipient cooling and changes in atmospheric circulation. However, the agency emphasizes that the phenomenon is not yet fully established and, for now, remains within the realm of probability, not certainty.
Although La NiƱa is traditionally associated with a temporary decrease in global average temperatureThe WMO clarifies that this does not imply, by any means, that the entire planet will experience colder temperatures. In fact, in a context of continued global warming, it is increasingly common for many regions to register above-average temperatures, even with La NiƱa active.
This mixture of natural forcing (La NiƱa) and anthropogenic warming complicates the forecasts and it can generate striking situations: areas where the ocean cools while the atmosphere near the surface remains marked by recurring episodes of unusual heat.
Risks of extreme weather events: heat, floods and droughts
The WMO warns that, despite talk of a weak episode, the risks for many regions They remain significant. The combination of a cooler Pacific and a planet that continues to accumulate heat favors an uneven distribution of rainfall and air masses, with potential cascading impacts.
Among the most likely effects, the organization cites a increased frequency of floods and droughts in different parts of the world, which could jeopardize agriculture and food security. The alteration of rainfall patterns can translate into damage to key cropswater supply problems and tensions in international agricultural markets.
At the same time, many areas could still be warmer than normalEven with La NiƱa underway, this is because global warming dominates the underlying trend, causing a phenomenon that used to partially offset rising temperatures to now have a diminished effect. In practice, we can go from extreme heat waves to "only" very intense heat, but we rarely return to the levels recorded decades ago.
The WMO highlights that this situation introduces greater uncertainties in sensitive sectors such as hydroelectric planning, reservoir management, forest fire prevention, or planting and harvesting schedules. A miscalculation in rainfall or temperature forecasts can have considerable economic repercussions.
Transition towards neutral conditions and absence of El NiƱo in the short term
Beyond the Northern Hemisphere winter, projections point to a phase change. The WMO anticipates that, as 2026 progresses, the following will be established: neutral conditions in the ENSO systemThat is, a state in which neither La NiƱa nor El NiƱo clearly dominates the evolution of the global climate.
The agency estimates that the probability of this neutral scenario ranges between 65% and 75% depending on the period considered, with particularly high values āābetween January and March, and between February and April. This transition is relevant because it tends to reduce the direct influence of the tropical Pacific on weather patterns, although it does not eliminate other factors that can lead to extreme weather events.
Meanwhile, the agency rules out the appearance of El NiƱo in the short termThis phenomenon, associated with a marked warming of the Pacific, usually intensifies tropical cyclones in that basin and increases rainfall across large areas of the Americas and other regions, raising the risk of flooding. According to the WMO, this scenario is not expected in the coming months.
It is worth remembering that the last episode of El NiƱo occurred in 2024, a year that ranks among the warmest ever recordedThe possible entry into a weak La NiƱa phase does not erase the cumulative effects of that period, nor does it reverse the underlying trends of climate change, but it can temporarily modulate some of its impacts.
Implications for Europe and Spain
Although La NiƱa is usually associated primarily with direct impacts in Pacific regions and parts of the Americas, Europe is not left out of its indirect effects. Large-scale alterations in atmospheric circulation can affect the position and intensity of Atlantic storms, as well as the frequency of anticyclonic blocking patterns.
In Spain, the influence of La NiƱa is more subtle and depends on how it interacts with other climate patterns, such as North Atlantic Oscillation (NAO) or the upper-level circulation over the Mediterranean. In some winters with La NiƱa, greater variability has been observed: periods of intense rainfall alternating with longer dry phases, and cold spells interspersed with incursions of warmer air.
European meteorological services often pay close attention to these WMO bulletins to adjust their own seasonal models. In a country so exposed to recurring droughts, forest fires, and torrential rains As in Spain, having an early signal, even if probabilistic, helps in planning water reserves, agricultural campaigns, and civil protection measures.
However, experts warn that Seasonal forecasts are not a day-to-day predictionbut rather a statistical guide to more likely trends. In other words, a higher probability of a slightly wetter or drier winter does not mean that isolated, very intense episodes in the opposite direction cannot occur.
Economic and social value of WMO forecasts
The WMO insists that the seasonal climate projections They are a key tool for anticipating impacts and reducing damage. According to the organization, when this information is properly integrated into decision-making, it can translate into millions of dollars in savings for sectors such as agriculture, energy, transport or public health.
A clear example is agricultural planning: knowing in advance that there is a higher probability of a drier or rainier period, adjustments can be made. planting dates, crop selection, and irrigation strategiesminimizing losses and optimizing resources. Similarly, electricity companies and network operators can better forecast energy demand and the availability of renewable resources such as hydropower or wind power.
In addition to the economic component, forecasts allow for the design of early actions that save livesHaving alerts about a possible increase in extreme phenomena makes it easier to activate evacuation plans, reinforce critical infrastructure, improve monitoring of river floods, or prepare health systems for heat waves or outbreaks of climate-related diseases.
The WMO emphasizes that the true value of these bulletins is multiplied when there is good coordination between meteorological services, authorities and citizensWithout an effective communication chain and without the population trusting and acting on the information received, the preventive potential of the forecasts is significantly reduced.
The perspective of a La NiƱa will be weak in the coming months.This, followed by a likely return to neutral conditions, paints a picture in which the cooling of the Pacific will not be enough to offset global warming, but it could temporarily modulate some rainfall and temperature patterns. In Europe and Spain, the key will be how these signals combine with other atmospheric patterns and the ability to use WMO information to anticipate, reduce economic impacts, and strengthen protections for people against an increasingly changing climate.