A potentially record-setting El Niño event is projected to reshape snowfall patterns across the United States during the winter of 2026–27. Analysis by CNN Weather indicates that historical trends suggest increased snowfall in parts of the South and reduced totals across several northern regions, including areas such as the Northern Rockies. While past patterns offer insights into regional differences, they cannot reliably predict specific snowfall amounts for individual locations during the season.
El Niño is a climate phenomenon characterized by unusually warm ocean temperatures in the central and eastern tropical Pacific. These temperature changes significantly influence atmospheric circulation and storm tracks, with their most pronounced effect on U.S. weather typically occurring during the winter months.
Historically, El Niño winters have brought above-average snowfall totals to various parts of the country. These regions include portions of the Southwest, the southern Rockies, the southern Plains, the southern Appalachians, and the Mid-Atlantic.
Conversely, other regions have consistently experienced below-average snowfall during El Niño events. These areas include parts of the Pacific Northwest, the Northern Rockies, the Great Lakes, and the Interior Northeast.
These regional differences in snowfall reflect fundamental changes in storm paths and ambient temperatures. While El Niño can increase precipitation in some areas, warmer conditions accompanying these events can lead storms to deliver rain rather than snow when temperatures are not sufficiently low for snowfall.
Jon Gottschalck, who serves as chief of the Operational Prediction Branch at NOAA's Climate Prediction Center and is the lead forecaster for the agency's winter outlook, noted that El Niño can intensify coastal storms impacting the Mid-Atlantic. He described these systems, known as nor'easters, as "very strong, energetic and they're very wet." These powerful storms could contribute to above-average snowfall in cities such as Washington, D.C., and Baltimore, with their effects partly dependent on whether storm tracks follow the Appalachian Mountains or develop offshore.
Further analysis reveals regional tendencies in snowfall frequency. Parts of the Southwest, lower Midwest, southern Appalachians, and Interior Northeast experienced above-average snowfall in more than half of the El Niño winters examined. Conversely, much of the Pacific Northwest, Northern Rockies, and parts of the Great Lakes recorded below-average snowfall more often than not. These regional tendencies tend to become more pronounced during moderate-to-strong El Niño events, with areas typically receiving more snow often exceeding their seasonal averages and regions usually receiving less snow more likely to remain below average. However, in southern areas where snow is uncommon, above-average snowfall may still result in relatively small accumulations.
Gottschalck emphasized that while a stronger El Niño makes its typical effects more likely, it does not guarantee a larger increase in rain or snow at a specific location compared to a weaker event. He also pointed out that the historical record contains a limited number of strong El Niño episodes, which restricts the certainty of conclusions drawn about their precise effects.
For the December-through-February period, the National Oceanic and Atmospheric Administration's outlook favors warmer-than-average temperatures across much of the northern and eastern United States. Gottschalck explained that the Pacific jet stream would be "flooding North America with Pacific Ocean air," potentially making it more difficult for prolonged Arctic outbreaks to persist.
Despite the broader outlook for warmer conditions, short periods of extreme cold remain a possibility. Changes in atmospheric circulation over the Arctic and North Atlantic could still direct cold air into the eastern United States and alter storm tracks, even during a strong El Niño. Forecasters are unable to reliably determine in advance when such cold episodes will occur or how long they might last.
The winter of 2015–16 serves as an illustration of how individual major storms can override broader seasonal tendencies. During that period of a very strong El Niño, New York City experienced one of its warmest winters on record, according to the National Weather Service. Nevertheless, a powerful blizzard in January 2016 dropped 27.5 inches of snow in Central Park, setting a new single-storm snowfall record for the city.