Two Giant Warming Patterns in the Pacific Set to Transform US Weather and Ecosystems A rare but powerful combination of an immense Pacific Ocean heatwave and a "super El Niño" is set to have profound effects on US weather and marine life this autumn. Scientists warn that the interplay of these two phenomena will reshape coastal conditions, intensify extreme weather events, and disrupt ecosystems across the West Coast and beyond. The heatwave, which began in May 2025, has already raised surface temperatures in the north-east Pacific by 3-4°C (5.4-7.2°F) above average for this time of year. Meanwhile, a developing El Niño event, expected to reach its peak this autumn, is amplifying the warming trend, potentially becoming the strongest in living memory. The north-east Pacific heatwave, described by NOAA oceanographer Andrew Leising as a "bright red eyeball" spanning the ocean, is already causing widespread ecological stress. Marine life is struggling as warmer waters reduce nutrient availability and oxygen levels, forcing species to migrate or perish. In California, where the heatwave has persisted since December, coastal water levels are already 15cm (5.9in) above mean sea level. During the El Niño, this rise is projected to increase by another 15-30cm (5.9-11.8in), significantly elevating flood risks for coastal communities. Warmer ocean temperatures also enhance evaporation, fueling heavier rainfall and atmospheric rivers that could trigger inland flooding and mudslides. In the Pacific Northwest and Canada, the combined effects of El Niño and the marine heatwave are expected to reduce snowfall and exacerbate drought conditions.#pacific_ocean #oregon_state_university #noaa #andrew_leising #larry_oneill
