TEMPO.CO, Jakarta - The US is bracing for the possible return of one of the world's most powerful climate phenomena as forecasters warn that the developing El Nino could strengthen into a rare Super El Nino later this year. If it does, the event could reshape weather patterns across North America, bringing heavy rain, flooding, severe storms, and unusually warm conditions to different parts of the country.
According to Newsweek, the US National Oceanic and Atmospheric Administration (NOAA) says El Nino conditions have already formed in the tropical Pacific and are expected to intensify through the second half of 2026. Forecast models suggest the event could rival some of the strongest El Nino episodes on record, although NOAA officially describes it as a "very strong" El Nino rather than a "super" El Nino.
What Is El Nino?
El Nino is a naturally occurring climate pattern that develops when sea surface temperatures across the central and eastern tropical Pacific Ocean become warmer than normal. Those warmer waters alter atmospheric circulation, affecting rainfall, temperatures, and storm tracks around the world.
As reported by Men's Journal, the term "El Nino," meaning "The Little Boy" or "Christ Child" in Spanish, was first used by fishermen along South America's Pacific coast because the warming waters typically appeared around Christmas.
Scientists generally use the informal term "super El Nino" to describe exceptionally strong events in which Pacific Ocean temperatures exceed about 2 degrees Celsius above average. Such events are rare. Since 1950, only a handful—including those in 1982-83, 1997-98, and 2015-16—have reached that level.
Muhammad Azhar Ehsan, an associate research scientist at Columbia Climate School, said the Pacific Ocean is already showing classic warning signs.
"The tropical Pacific is already showing several classic early warning signs," Ehsan said.
He explained that unusually warm subsurface ocean temperatures are rising toward the surface, providing the heat needed for El Niño to strengthen.
Why Scientists Are Closely Watching the Pacific
According to NOAA, there is an 81 percent chance that the current El Niño will become very strong between October and December 2026, while the agency estimates a 97 percent chance it will continue into early spring 2027.
Researchers are monitoring a large pool of unusually warm water beneath the Pacific Ocean's surface, which continues feeding the developing climate pattern. Atmospheric changes, including shifts in tropical Pacific winds, also indicate stronger coupling between the ocean and atmosphere—a key factor behind major El Niño events.
NOAA's Geophysical Fluid Dynamics Laboratory has also projected an exceptionally strong event, with all 30 members of its experimental forecast ensemble predicting an El Niño comparable to the strongest observed over the past century.
Still, forecasters caution that even powerful El Nino events do not produce identical weather outcomes every time.
"The strongest El Niño events do not lead to the typical impact everywhere, but stronger events can more significantly tilt the odds in favor of expected outcomes," NOAA's Climate Prediction Center said.
Which U.S. States Face the Biggest Risks?
Although detailed winter forecasts will not be finalized until later this year, historical weather patterns offer clues about which parts of the United States are most vulnerable.
California is expected to be among the biggest areas of concern.
AccuWeather Lead Long-Range Forecaster Paul Pastelok said Southern California could experience very heavy winter rainfall, while the Sierra Nevada mountains may receive substantially above-average snowfall.
According to Newsweek, California's Sierra region, along with New York, Vermont, and New Hampshire, is expected to have the greatest chance of significant snowfall this winter.
Meanwhile, wetter-than-normal conditions are forecast across much of the southern United States.
Johnna Infanti, a meteorologist at NOAA's Climate Prediction Center, said above-normal precipitation is expected across the Gulf Coast, the Southeast, and parts of the Mid-Atlantic.
States including Georgia, Alabama, Mississippi, South Carolina, Florida, Texas, and Louisiana may experience heavier rainfall and stronger winter storm systems.
Florida could also face a greater risk of severe thunderstorms and tornadoes during the cool season.
Mark Wiley, a duty officer with the US National Weather Service, warned that stronger El Nino conditions also raise the risk of flash flooding and river flooding throughout the Deep South and Gulf Coast.
"A strong El Nino increases the chance of winter precipitation across the Southern US if enough cold air is in place, particularly for freezing rain," Wiley said.
By contrast, much of the northern United States and the Pacific Northwest typically experience warmer and drier winters during strong El Nino years, although local conditions can vary.
A Different Kind of Winter
As reported by Men's Journal, Columbia University notes that previous major El Niño events produced dramatically different winter conditions across the United States.
During the powerful 1997-98 El Niño, much of the southern U.S. experienced unusually wet weather, while northern states recorded warmer-than-average temperatures. That winter became the country's second warmest and seventh wettest since records began in 1895.
The northeastern United States, which just experienced one of its snowiest winters in more than a decade, could again see above-average snowfall in parts of the region if current forecasts hold.
Effects Beyond the Weather
The impacts of El Nino extend beyond rainfall and snowfall.
According to Newsweek, warmer Pacific waters may also reshape marine ecosystems along the US West Coast.
Marine scientists expect tropical species such as mahi-mahi, bluefin tuna, juvenile white sharks, stingrays, sea turtles, and even yellow-bellied sea snakes to move farther north as ocean temperatures rise.
Douglas McCauley, director of the Benioff Ocean Initiative at the University of California, Santa Barbara, said researchers expect "all kinds of weird tropical things" to appear in California waters.
Chris Lowe, director of the Shark Lab at California State University, Long Beach, described the shift as creating "this whole different ocean," as warmer water alters marine food chains and fish migration patterns.
What Happens Next?
Forecasters say the coming months will determine whether the developing Super El Nino reaches historic strength.
If Pacific Ocean temperatures continue rising at their current pace, the 2026-27 event could rank among the strongest on record.
Emergency management agencies, weather services, and water authorities across the United States are already monitoring conditions closely as they prepare for a winter that could bring very different weather depending on where Americans live.
Read: Super El Nino Forecast Is Out: What Should We Expect?
Click here to get the latest news updates from Tempo on Google News
