El Niño: à quoi s'attendre pour l'Argentine en septembre, octobre et novembre

The European Centre for Medium-Range Weather Forecasts (ECMWF) has released its updated forecast for the three-month period spanning September, October, and November 2026, highlighting the evolving impact of the El Niño phenomenon on Argentina’s weather patterns. As the El Niño event strengthens in the equatorial Pacific Ocean, the international organization has outlined projected rainfall patterns and average temperatures for different regions of the country. According to the latest projections, while extreme heatwaves are not anticipated early in the trimester, the overall thermal behavior shows a shift toward cooler-than-usual conditions in some areas. The focus of increased humidity and sustained precipitation is concentrated in the northeastern part of Argentina, including the provinces of Corrientes, Misiones, parts of Chaco and Formosa. These regions are directly influenced by the warm phase of the Southern Oscillation, which enhances moisture availability and supports more frequent rain events. The seasonal forecasts from the ECMWF model indicate notable variability across Argentina during spring. In the northeast, the signal of higher-than-average rainfall persists throughout the trimester, with precipitation levels exceeding historical norms. Meanwhile, the central and Pampas regions experience rainfall close to long-term averages or slightly above them, offering favorable conditions for agricultural planning. However, the southern and western parts of the country, particularly the Cuyo and Patagonia regions, are expected to see below-normal rainfall totals, contributing to a potential water deficit in these areas. In contrast, other parts of the country show weaker and more variable signals. While the central region maintains near-normal rainfall with some positive anomalies, the western and parts of Patagonia face less favorable conditions. This regional variation underscores the complexity of the upcoming climate scenario, emphasizing the need for localized monitoring and adaptive strategies. The report from the ECMWF serves as a critical tool for agricultural planning in the 2026/2027 cycle. The replenishment of soil moisture reserves in the Pampas benefits the planting of coarse crops, although alerts remain active in the basins of the Paraná and Uruguay rivers due to potential flooding linked to excess rainfall in the northeastern area. Celeste Saulo, the secretary-general of the World Meteorological Organization and former director of the National Meteorological Service, noted that the presence of El Niño influences the seasonal temperature pattern. For the months of September through November, she expects a spring characterized by above-average rainfall in the Litoral and eastern fringe, alongside average or slightly cooler temperatures in the central zone. This configuration is especially noteworthy given the context of the ongoing El Niño event, which can alter atmospheric circulation patterns and enhance humidity and precipitation activity over certain parts of South America. However, the effects are not uniform across the continent, underscoring the importance of continued observation and local expertise in interpreting these broader climatic trends.