The National Oceanic and Atmospheric Administration's May outlook gives El Nino a 61 percent probability of developing between May and July. The probability that it develops into a Super El Nino — defined as sea surface temperature anomalies in the Nino 3.4 region exceeding two degrees Celsius above normal — is now approximately 50 percent. In meteorological terms that is a coin flip. In agricultural terms for Latin America it is not. [1]
The 1997–98 El Nino remains the calibration event. It pushed Pacific surface temperatures 2.5 degrees Celsius above baseline at peak intensity, disrupted precipitation patterns across the globe, and produced severe drought in northeast Brazil, flooding in coastal Peru and Ecuador, and crop failures that took multiple growing seasons to recover. Global commodity markets priced the disruption. Food import costs in affected countries rose sharply. [1][2]
Brazil is the country most exposed to a replay. Mato Grosso and Mato Grosso do Sul, the core of Brazil's soy production, experienced acute drought during the 1997–98 event. The country has since expanded its agricultural footprint significantly — Brazil is now the world's largest soy exporter, accounting for more than 35 percent of global supply — which means the scale of any disruption is proportionally larger. A Super El Nino that cuts Brazilian soy production by 10 to 15 percent would move global oilseed markets in ways that extend well beyond South America. [2]
The NOAA probability is for the May–July onset window, not a full-year forecast. El Nino events that begin in northern hemisphere summer typically peak in December and January, which aligns with the South American growing season. The timing is the problem. If the event develops on schedule, the intensification phase arrives precisely when Brazilian soy is most vulnerable — during germination and early growth in October and November. [1]
Argentina faces analogous risks. The Pampas, Argentina's primary agricultural region, produced record grain output in 2024 and 2025. A strong El Nino typically produces flooding rather than drought in the Pampas during peak growing months, which creates a different but equally damaging problem: saturated soils, delayed planting windows, and quality losses from excess moisture. [2]
The 50-50 odds on a Super El Nino reflect genuine scientific uncertainty. The Nino 3.4 anomaly forecasts carry wide ensemble spread at this lead time — models diverge significantly on whether the event reaches 1.5 degrees Celsius, the threshold for a strong event, or pushes past two degrees into the super category. The WMO and NOAA both publish ensemble ranges rather than single-point forecasts specifically because this kind of ambiguity is real, not false modesty. [1]
What is not uncertain is the direction. Sea surface temperatures in the central and eastern tropical Pacific are already trending toward El Nino thresholds. The question is magnitude. And magnitude is what separates a difficult agricultural year in Latin America from a generational disruption.
Climate accounts on X are already running the 1997–98 comparison as a near-certainty. That is too fast. The ensemble spread is wide enough that a moderate El Nino — disruptive but manageable — remains the more probable outcome if the 39 percent non-development scenarios are bundled with the lower-intensity development scenarios. A Super El Nino at 50-50 means there is still a coin-flip chance of staying below that threshold. [1]
The region's agricultural ministries and commodity traders are watching the June update. That outlook, with three additional months of observed sea surface temperatures, will narrow the ensemble spread considerably. By then, Brazilian producers will have made their initial planting decisions and early input purchases. What they know by June will shape what they plant by October. The NOAA forecast is not the emergency. The June confirmation would be.
-- LUCIA VEGA, São Paulo