El Niño has officially formed, and scientists now warn it could become one of the strongest on record. A new analysis released on July 23 says there is a 90% chance the warming in the tropical Pacific will push beyond anything recorded in about 150 years of observations.
That is why the search for El Niño North America weather is peaking now. The pattern’s biggest U.S. effects are still ahead, with the first broad changes expected in the fall and the strongest impacts likely to land in winter, when the storm track usually shifts south and reorganizes rainfall, temperature and snow from coast to coast.
Michelle L'Heureux said El Niño tends to increase the storm track over the southern tier of the United States, increasing the chances of above-average precipitation. In practical terms, that means wetter and cooler-than-normal conditions are more likely from late fall through winter across the Gulf Coast and the lower Mississippi and Tennessee valleys, while the northern U.S. leans warmer and drier. El Niño also often brings wetter-than-normal conditions across parts of the Southwest, including the Great Basin and southern Rockies, and parts of the Rockies can see above-normal snowfall even as western and central Canada trend milder with below-normal snowfall.
The pattern does not help everyone in the same way. A stronger El Niño can suppress Atlantic hurricane activity, but it does not shut down the risk from every coastal storm. Powerful systems, including nor'easters, can still be elevated even in a quieter hurricane season, and that is one reason forecasters are watching the winter setup so closely.
The broader effect is a familiar one with a bigger scale than usual: El Niño can reshape weather across North America by steering more storms across the South, increasing thunderstorm activity along the Gulf Coast and into the Tennessee Valley, and reducing spring and summer wildfire risk across the Southeast. For Steven DiMartino, the tropical side of the forecast is part of the same story. He said a very strong El Niño produces significant wind shear in the tropical Atlantic, and that wind shear prevents most tropical waves from forming.
The World Meteorological Organization expects El Niño to persist well into late 2026, which means the impact is not likely to be a short-lived burst. If the tropical Pacific keeps warming past the historical record, the next question is not whether El Niño matters, but how long the country will be living with its effects once winter arrives.
