NOAA confirms critical El Niño phase as specialists warn of what could come next

El Niño is strengthening in the equatorial Pacific, and NOAA forecasts more than a 90% chance that the phenomenon will reach the “very strong” category during the Northern Hemisphere’s autumn and winter.

The National Oceanic and Atmospheric Administration, through its Climate Prediction Center, continues to maintain an El Niño advisory as oceanic and atmospheric conditions develop. Recent records published on August 31 showed continued warming in the central and eastern equatorial Pacific. During July, sea-surface temperature anomalies exceeded 2°C in parts of the eastern equatorial Pacific.

By the end of August, the Niño 3.4 index had reached +1.8°C, while Niño 3 stood at +2.6°C and the coastal Niño 1+2 region reached +3.5°C. Forecasters also identified low-level westerly winds, upper-level easterly winds and increased rainfall activity extending from the central to the eastern Pacific. These oceanic and atmospheric signals help determine whether El Niño conditions are present and track their development.

NOAA does not expect the phenomenon to change suddenly from one day to the next. ENSO develops over longer periods, so meteorological authorities continue to monitor oceanic and atmospheric indicators. Models give El Niño a more than 90% chance of becoming very strong during the Northern Hemisphere’s autumn and winter. From October through December, there is a 69% chance that it will exceed previous records dating back to 1950.

For the United States, NOAA’s September-to-November outlook combines the ENSO signal with long-term climate trends and existing soil moisture. It points to above-average temperatures across much of the country, with the West, Pacific Northwest, Southwest, Northeast and Alaska among the areas most likely to be warmer than usual. Rainfall prospects vary by region, but the Southwest, including Arizona, Utah, Colorado, New Mexico and parts of Texas, has a greater chance of above-normal precipitation.