Major cities such as Los Angeles and Atlanta might experience increased rainfall, flooding, and other weather challenges this winter due to a strengthening El Niño. Paul Pastelok, AccuWeather’s lead long-range expert, shared this with Newsweek. The federal forecasters indicate that this climatic phenomenon is predicted to intensify through the year’s end, with a higher than 90 percent chance of becoming a particularly strong event during the fall and winter.
Understanding El Niño
El Niño represents the warm phase of the El Niño-Southern Oscillation (ENSO), a recurring climatic pattern in the Pacific that impacts global weather. Its opposite, La Niña, serves as the cool phase of this cycle. Common effects of El Niño include stormier weather across southern regions, drier conditions in northern areas, and changes in hurricane patterns.
Historically, strong El Niño episodes have led to extreme weather events. For instance, the 1997-98 Super El Niño resulted in severe flooding in California and Peru. The 2015-16 occurrence was associated with global temperature records and extensive climate disturbances.
Potential Impact on Major Cities
“With a robust El Niño, cities like Los Angeles, San Francisco, Houston, and Atlanta are typically affected by increased rainfall and potential flooding,” Pastelok explained to Newsweek. He noted that these southern storm tracks can cause more frequent and intense impacts throughout late fall and winter. California’s landscape makes it especially susceptible to landslides under such conditions.
Increased river levels could also concern areas along the Mississippi, in the Tennessee Valley, and the Carolinas, affecting cities along these waterways. East Coast cities like Norfolk, Atlantic City, and Boston may experience strong storms, leading to coastal flooding and high winds.
NOAA’s Winter Outlook Insights
The National Oceanic and Atmospheric Administration’s (NOAA) Climate Prediction Center (CPC) maps for December 2026 through February 2027 forecast above-normal temperatures over a wide region. This range includes areas from the Pacific Northwest and northern Rockies through the Midwest to the Northeast. The most pronounced warm signals are expected along the northern tier of the country.
In the South, above-normal temperatures are predicted, although projections in California and the Southwest remain uncertain. Precipitation maps suggest wetter-than-normal conditions from Southern California through the Southwest, southern Plains, Gulf Coast, extending into Florida and parts of the East Coast.
Recently, the CPC increased the probability of El Niño reaching historic intensity during the October-to-December period to 75 percent. This is up from 69 percent in their August update. A significant event increases the chances of experiencing typical El Niño weather, but these effects aren’t guaranteed.