NASA Warns El Niño Could Reach Historic Intensity, Raising Pacific Sea Levels

NASA satellites are tracking changes in Pacific Ocean temperature and sea level caused by the intensifying El Niño phenomenon. Warm waters are moving eastward, and sea levels in some areas have risen by 40 centimeters above long-term averages.

NOAA estimated on October 18 that there is an 83 percent chance this is the strongest El Niño episode since 1950. The natural climate pattern typically occurs every two to seven years and features unusually warm ocean temperatures in parts of the Pacific.

“We're already seeing this start to play out in California, where we've seen some major flooding occurring in the aftermath of tropical storm Rachel.”

Scientists monitor sea surface height, warm water expansion, and ocean color changes to follow the event's evolution. These Pacific transformations can affect weather patterns worldwide, though NOAA says they cannot predict with certainty how conditions will look in each region.

Researchers warn that elevated ocean patches could worsen an already supercharged storm season. A new pre-print study forecasts a tenfold rise in extreme sea-level risk along coastlines from Alaska to Chile during the 2026-27 El Niño.

Major flooding has already occurred in California after tropical storm Rachel. Study coauthor Thomas Monahan said the biggest tidal peaks are expected during Thanksgiving and Christmas weeks, among the busiest travel periods.

The analysis also considered the Moon's 18.6-year lunar nodal cycle, which adds unique gravitational effects to high tides. Monahan worked with researchers from Oxford, Woods Hole Oceanographic Institution, and the University of Central Florida on the assessment.