The ocean has not yet spoken to the atmosphere
Beneath the surface of the equatorial Pacific, heat is accumulating in ways that may reshape Argentina's seasons from spring 2026 through early 2027. The phenomenon known as El Niño is underway, yet its intensity remains suspended in uncertainty — the ocean has stirred, but the atmosphere has not yet answered. Scientists describe this moment as a threshold: June will determine whether the signal sharpens into something foreseeable or dissolves into noise. Argentina, like so many nations shaped by distant waters, waits at the edge of what can be known.
- Warm water is already rising in the equatorial Pacific, setting the early conditions for an El Niño event that could alter Argentina's weather through spring, summer, and into 2027.
- The critical unknown is not whether El Niño arrives, but how powerful it becomes — and that answer remains locked behind a seasonal wall of atmospheric unpredictability.
- Forecasters warn that current models carry too much noise to trust: small fluctuations in data can swing predictions dramatically, making confident planning nearly impossible before June.
- The ocean and atmosphere must begin their dialogue in the coming weeks — if warming lacks regional contrast, the atmosphere may never fully respond, weakening the event's reach.
- June's NOAA report represents the clearest turning point: once ocean-atmosphere coupling tightens, the forecast becomes more deterministic and Argentina can begin preparing in earnest.
El calentamiento ya está en marcha. En las primeras capas del océano Pacífico ecuatorial, las temperaturas suben, y la mayoría de los pronósticos sugieren que ese calor comenzará a moldear el clima argentino a partir de septiembre, extendiéndose posiblemente hasta comienzos de 2027. Lo que nadie sabe todavía es cuán intenso será el fenómeno.
Los científicos que estudian estas variaciones enfrentan un desafío particular en esta época del año. Osman, investigador de la Universidad de Buenos Aires especializado en variabilidad climática del hemisferio sur, explicó que los modelos meteorológicos de diez días se estiran hasta diez meses para anticipar patrones estacionales, pero la confiabilidad de esas proyecciones sigue siendo baja. Las temperaturas en las capas superiores del Pacífico sugieren altas probabilidades de que El Niño se consolide en la primavera austral, aunque esas probabilidades vienen acompañadas de importantes reservas.
Pedro Di Nezio, meteorólogo con experiencia en investigación sobre El Niño en universidades estadounidenses, describió el umbral de predictibilidad que llega cada primavera boreal. Hoy, cualquier pequeña fluctuación en los datos puede torcer el pronóstico. Pero a medida que se acerca junio, el sistema se vuelve más determinista: cuando el océano y la atmósfera comiencen a interactuar con mayor intensidad, el patrón tenderá a mantenerse en la dirección que tome.
El nudo central no es si El Niño llegará, sino qué forma adoptará. El agua cálida ya avanza hacia el este, pero para que el fenómeno se consolide, la atmósfera debe responder: los vientos necesitan desarrollarse y reforzar el calentamiento. Osman señaló que incluso existe la posibilidad de que, si el océano se calienta de manera uniforme sin generar contrastes entre regiones, la atmósfera no reaccione. Es precisamente ese contraste —una zona calentándose más que otra— lo que desencadena los cambios en vientos y presiones que amplifican el efecto de El Niño.
Hasta que la NOAA publique su informe de junio, Argentina permanece en un estado de incertidumbre informada: sabe que algo se aproxima, pero aún no puede saber qué exigirá.
The warm water is already rising in the Pacific. Somewhere beneath the surface, in the first few meters of ocean off the equator, temperatures are climbing. By most forecasts, this warmth will shape Argentina's weather from September onward, through the spring and summer months ahead, possibly extending into early 2027. But nobody yet knows how strong it will become.
This is the peculiar position Argentina finds itself in as May turns toward June. The phenomenon known as El Niño—born from the accumulation of heat in Pacific waters—is underway. The question that matters most remains unanswered: how intense will it be?
Climate scientists who study these patterns face a particular challenge this time of year. Osman, a researcher at the University of Buenos Aires who has spent years analyzing climate variability across the Southern Hemisphere, explained the bind they're in. Meteorologists have developed a practice of taking ten-day weather models and stretching them forward ten months to predict seasonal patterns. But when you examine those predictions closely, he said, you find reasons for caution. The reliability of forecasts for El Niño events at this stage remains low. The water temperatures in the Pacific's upper layers suggest strong odds that El Niño will develop by Argentina's spring and summer—starting in September. Yet the confidence in those odds is qualified, hedged by the limits of what can actually be known.
Pedro Di Nezio, a meteorologist who has collaborated on El Niño research at American universities, described the barrier that constrains prediction at this moment. There is a threshold of predictability that arrives each northern spring. It marks the limit of how far ahead forecasters can see with any real certainty. Right now, he explained, El Niño predictions carry too much noise. Any small fluctuation in the data can push the forecast in different directions. But as June approaches, something shifts. The system becomes more deterministic. Once the ocean and atmosphere begin to interact more directly, if the pattern moves in one direction, it will continue that way. The coupling between water and air tightens the forecast.
The core uncertainty is not whether El Niño is coming, but what form it will take. The warm water is already moving eastward across the Pacific, emerging in the equatorial zone. For the phenomenon to fully consolidate, however, the atmosphere must respond. Wind patterns need to develop that will reinforce the warming. This is where the story becomes complicated. Ocean and atmosphere operate on different timescales. Weather can be predicted a week out, but then turbulence breaks the chain of causation. Yet ocean patterns can be observed eight or nine months ahead. The challenge is that those ocean signals must communicate themselves to the atmosphere, and the atmosphere is what carries the impact far from the tropical Pacific—to Argentina, to other distant regions.
Osman pointed to June and July as the critical months. Right now, warm water is emerging. But the ocean has not yet spoken to the atmosphere. That conversation activates in the coming weeks. There is even a possibility, he noted, that if the entire ocean warms uniformly without creating contrast between regions, the atmosphere might not respond at all. Often what triggers atmospheric change is precisely that contrast—one zone heating more than another—which generates shifts in wind and pressure patterns that unleash the full El Niño effect.
Di Nezio noted that geological records show El Niño has always existed, fluctuating between weaker and stronger episodes. But he was clear: predictions this far in advance cannot be trusted. Only when the National Oceanic and Atmospheric Administration releases its June report will the picture clarify. Until then, Argentina waits in a state of informed uncertainty, knowing something is coming but not yet what it will demand.
Notable Quotes
The great unknown now is what intensity El Niño will reach— Pedro Di Nezio, meteorologist
The atmosphere must respond with wind patterns that reinforce the warming for the phenomenon to consolidate— Osman, climate researcher, University of Buenos Aires
The Hearth Conversation Another angle on the story
So the warm water is already there in the Pacific. Why can't they just measure it and tell us what's going to happen?
Because the ocean and the atmosphere are two different systems. You can see the heat building underwater months in advance. But that heat only matters if the atmosphere picks it up and amplifies it. Right now they're not talking to each other yet.
When do they start talking?
June, July. That's when the atmosphere is supposed to respond to what the ocean is doing. If it does, the pattern locks in and becomes predictable. If it doesn't, everything changes.
And if the atmosphere doesn't respond?
Then El Niño might fizzle. Or it might still develop but differently than expected. The contrast matters—if one part of the ocean heats up more than another, that's what triggers the wind shifts that make El Niño real.
So June is the hinge.
Exactly. Right now any small fluctuation in the data could push the forecast in different directions. But once June arrives and the ocean-atmosphere coupling tightens, the forecast becomes much more solid. That's when Argentina will actually know what's coming.