Satellites Track an El Niño That Could Become the Strongest Since 1950

The El Niño now spreading across the tropical Pacific is still gaining strength and could become the most powerful on record since at least 1950, according to new NASA satellite analysis released this week and the latest outlook from the National Oceanic and Atmospheric Administration.

El Niño is a natural swing in the Pacific in which the trade winds weaken and warm water that normally piles up near Indonesia sloshes east toward South America. It changes weather far beyond the ocean, shifting storm tracks and rainfall patterns around the world.

NASA scientists said satellites first caught the start of this event in January 2026, when they spotted a Kelvin wave, a slow pulse of warm water, near Micronesia. By early April those waves had reached the eastern Pacific and surface temperatures there began climbing. Satellite measurements of sea height, which rises as water warms and expands, now show water up to roughly 30 to 40 centimeters, or about a foot, above normal near South America and moving north along the coast toward California, and water 15 to 20 centimeters below normal around Indonesia and northern Australia.

Surface waters in the eastern Pacific are about 1.7 degrees Celsius, or 3 degrees Fahrenheit, warmer than the long-term average, and could warm a bit more in the coming months, said Josh Willis, a sea level scientist at NASA’s Jet Propulsion Laboratory. NASA’s PACE satellite has also found that the equatorial Pacific has turned measurably bluer, a sign of fewer phytoplankton, because weaker winds bring less nutrient-rich deep water to the surface. That change can ripple up the marine food chain.

NOAA’s Climate Prediction Center, in its monthly update on October 8, kept its El Niño advisory in place and said the event was still strengthening. Its key ocean temperature index for the central Pacific stood about 2.1 degrees Celsius above normal for the latest month, and readings closer to South America were higher still. The center said a strong to very strong El Niño is likely to last through early 2027, and it put the chance of a historic event, one exceeding any El Niño since 1950 by its measure, at about 83 percent for the October to December period.

Forecasters stress that a strong El Niño tilts the odds rather than guaranteeing a particular winter. NOAA said impacts typical of El Niño are more likely with an event of this size but not assured, and it pointed to its seasonal outlooks for regional chances. NASA noted that the extra heat and moisture a warm ocean pumps into the atmosphere can feed rainstorms and shift weather patterns worldwide.

The satellite record matters because it lets scientists watch the event unfold in near real time across an ocean too large to monitor with ships and buoys alone. NASA said farmers, firefighters and coastal communities are already feeling the effects, and the next several months will show whether this El Niño reaches the record its numbers suggest.