Researchers have identified a significant reservoir of heat under the tropical Pacific Ocean that is influencing surface conditions, potentially leading to a stronger El Niño later this year. The European Center for Medium-Range Weather Forecasts (ECMWF) shows that this subsurface heating is already affecting seasonal forecasts, despite cooling surface temperatures.
Warm water is moving eastward below the surface, which can disrupt normal trade winds. When these winds weaken, surface heat can migrate toward South America, further warming the eastern Pacific and impacting the atmosphere. Forecasters are monitoring temperature anomalies, especially in the Niño 3.4 region, as even slight increases can significantly alter weather patterns.
The NOAA Climate Prediction Center predicts a 62% chance of an El Niño event occurring from June to August, with increasing probabilities thereafter. However, the spring season complicates forecasts, a phenomenon known as the "spring predictability barrier," making accurate predictions challenging.
The continuing rise in ocean temperatures is likely to alter jet stream patterns, leading to varied weather outcomes across North America, including potential flooding and mild conditions in different regions. Additionally, rising coastal temperatures may disrupt local ecosystems and fisheries.
In upcoming weeks, new winds could enhance subsurface heat, raising surface temperatures further. The study emphasizes the importance of early warnings for communities to prepare for El Niño’s impacts, as current conditions suggest a greater likelihood of significant events as the year progresses. The research is published in Geoscientific Model Development.
