NOAA sees over 90% chance of record El Nino this winter

A rapidly intensifying El Niño is on track to become the strongest on record, with forecasters warning of far-reaching consequences for weather patterns, marine ecosystems, and global temperatures through 2027.

NOAA's Climate Prediction Center said in its August diagnostic discussion that El Niño is strengthening, with a greater than 90% chance of a very strong event during the Northern Hemisphere fall and winter of 2026-27. The agency gave a 69% chance that the event will exceed the strength of all previous El Niños dating back to 1950, defined as a three-month average sea surface temperature anomaly of 2.5°C or more in the key Pacific monitoring region. NOAA data show that the 2026 El Niño forecast mean of 2.66°C would rank as the strongest in the historical record if it verifies.abcnews+3

Sea surface temperatures in the eastern equatorial Pacific are already more than 2°C above average, and several forecasts indicate the anomaly could surpass 3°C as the event reaches its peak later this year.sanews+1

A Double Threat in the Pacific

The developing El Niño is arriving alongside a massive marine heatwave that has persisted in the northeast Pacific since May 2025, with surface temperatures running 3-4°C above normal. NOAA researchers describe the heatwave as spanning nearly the entire ocean basin, and it is only the second time in documented history that a marine heatwave of this scale has coincided with an El Niño.bbc

The combination is expected to reshape weather across the United States. California faces increased storm surges and flooding risk as warmer coastal waters amplify atmospheric rivers, while the Pacific Northwest could see reduced snowfall and worsening drought conditions. In the Atlantic, El Niño's wind shear tends to suppress hurricane formation, though warmer waters in the eastern Pacific may fuel stronger tropical storms.bbc

Global Consequences

The South African Weather Service warned on Tuesday that the event could bring below-normal rainfall and above-normal temperatures across most of southern Africa from October through at least January 2027, raising concerns about drought, severe heatwaves, and water scarcity. SAWS said the combination of a very strong El Niño and ongoing global warming will likely make 2027 the warmest year ever recorded.iol+1

Climate Impact Company's latest diagnostics point to additional effects worldwide, including drying across Indonesia and India, heavier rainfall in East Africa and the Middle East, and a stormy pattern for California and the southern United States as the cool season approaches.climateimpactcompany

An Uncertain Scale

Despite the alarming trajectory, scientists caution that not every strong El Niño produces identical outcomes. The very strong 1997-98 event, for instance, brought slightly above-normal rainfall to parts of South Africa's summer rainfall region rather than drought. A recent study published in Science found evidence that El Niños have grown stronger compared with pre-industrial conditions, though not all researchers agree on the interpretation.ibtimes+1

El Niño events typically last 9 to 18 months, with this one expected to subside around spring 2027. Until then, forecasters say the Pacific will remain the dominant force shaping global weather.bbc