A NASA satellite has detected a warm Kelvin wave moving eastward across the Pacific Ocean, signaling a precursor to an El Niño event.
This discovery is critical because these waves typically precede the development of El Niño, which can alter global weather patterns and increase the risk of extreme weather events later in the year.
The Sentinel-6 Michael Freilich satellite collected the data between March and May 2026 [1]. The observations tracked higher, warmer water moving from the western Pacific toward the coasts of Colombia, Ecuador, and Peru [1], [2]. This movement of warm water is a known telltale sign that an El Niño event is forming [3].
NASA scientist Josh Willis said that the current cycle is developing differently than previous major events. "This year's started a bit later than the big El Niños of 2015 and 1997, it's beginning to catch up," Willis said [4].
Monitoring sea levels and surface temperatures allows scientists to track the progression of these waves in real time. The Kelvin wave acts as a trigger, pushing warm water toward the eastern Pacific and suppressing the usual upwelling of cold, nutrient-rich water along the South American coastline [1].
While the timing of this year's precursor is slightly delayed compared to historic "super" events, the data suggests a significant El Niño could still form later in 2026 [1], [4]. The satellite team continues to monitor the eastern Pacific to determine the eventual strength and impact of the phenomenon [1].
“A warm Kelvin wave is a known precursor to an El Niño event.”
The detection of a warm Kelvin wave provides an early warning system for global meteorological agencies. Because El Niño often leads to droughts in some regions and heavy flooding in others, this data allows governments and agricultural sectors to prepare for potential climate disruptions before the full event manifests in late 2026.
