Strong El Niño and the snow map: Which states might see more snow this winter

The rapid strengthening of El Niño is reshaping the outlook for winter. The NOAA warns of a greater than 90% chance of a "very strong" event this fall and winter, and a 69% chance that October through December will exceed the intensity of those recorded since 1950.

What NOAA says: An event that is already "very strong"

NOAA's Climate Prediction Center (CPC) explains in its August 13 assessment that El Niño has intensified over the past month, with sea surface temperature anomalies exceeding +3.6 °F in the eastern equatorial Pacific.

In July, the equatorial Pacific was already clearly warmer than normal: about 2.5 °F above average in the region NOAA uses to declare El Niño, 3.1 °F a little further east and 5.2 °F off the coast of South America. In addition, subsurface temperatures showed significant anomalies (up to +18 °F at depth), reflecting a deeper-than-normal thermocline.

The CPC's official outlook, which integrates multiple models, indicates that El Niño will continue to strengthen through the end of the year. During the October–December period, there is a 69% probability of a historic event (greater than +4.5 °F on the quarterly RONI index). NOAA emphasizes that, with an event of this magnitude, the chances of typical El Niño impacts increase, although they are not guaranteed.

Why it matters for snow: the jet stream shifts southward

El Niño pushes the Pacific jet stream further south, triggering a wetter storm track in the southern half of the country. Historically, moderate-to-strong El Niño winters tend to produce more precipitation and, at higher elevations, more snow in parts of the southern and central Rocky Mountains and the Southwest.

Meteorologist Crystal Egge, president of Monarch Weather Consulting, notes in Newsweek that states such as California, Nevada, Utah, Colorado, New Mexico, and Arizona could see above-average snowfall in the coming months, especially at high elevations. "Historically, strong El Niño winters tend to favor a wetter storm track across the southern tier of the U.S. That can translate to above-average snowfall across parts of the southern and central Rockies and the higher elevations of the Southwest," she explains.

This increase in mountain snow is key: the snowpack acts as a natural reservoir, releasing water in the spring and summer. "This year, the need for mountain snow is particularly important. Much of the West is coming off a very dry start to the water year, so building that snowpack will be critical for water supplies and overall drought conditions heading into 2027," adds Egger.

NOAA's seasonal outlook calls for above-normal precipitation across much of California, the Southwest, and the southern region, with a more than 50% chance of above-average precipitation in parts of the California coast and southern Arizona during parts of the winter.

The flip side: Warmer north and fewer snow chances

The same pattern that brings moisture to the south tends to leave the north milder. NOAA's winter outlook calls for above-normal temperatures across much of the northern region, with probabilities exceeding 50% from the Pacific Northwest to the Northeast between December and February.

Egger notes that these warmer conditions reduce the chances of precipitation falling as snow. "The flip side is that El Niño typically favors warmer conditions across the northern tier of the U.S., including parts of the Pacific Northwest, northern Rockies and Upper Midwest," she says.