Federal scientists now estimate a 95% chance that a 'super' El Niño will develop this year, with a 69% probability it will exceed the strength of all recorded events since 1950, according to the National Oceanic and Atmospheric Administration’s Climate Prediction Center (CPC).
The agency reported Thursday that El Niño has strengthened significantly over the past month, with sea-surface temperatures in the eastern equatorial Pacific more than 3.6 degrees above average. There is now a 70% chance it will reach the highest classification of "very strong," a threshold previously met only three times since 1950.
Potential Impacts and Regional Variations
The CPC noted that while El Niño events typically bring above-average rainfall to Southern California, past patterns have varied. The 2015-16 El Niño, despite being one of the strongest on record, did not produce higher-than-average precipitation in Southern California but was linked to record beach erosion along the state’s coast. The 1982-83 and 1997-98 events, however, did bring significant rainfall to the region.
El Niño is defined by warmer-than-average ocean temperatures in the central and eastern tropical Pacific, accompanied by weakened or reversed trade winds. This shift can redirect tropical moisture toward Southern California, though its effects are not uniform across the state or the country.
Historical Context and Unprecedented Warming
The current El Niño is developing under unprecedented conditions. The CPC reported a 69% chance that ocean temperatures in the tropical Pacific will reach or exceed 4.5 degrees above baseline—a threshold never recorded in modern history. The previous record, set during the 1982-83 El Niño, measured 4.32 degrees above baseline.
Michelle L’Heureux, the El Niño team lead for the CPC, stated that this development has never been observed in the historical record dating back to 1950. The agency’s latest forecast, based on multiple climate models from North America and abroad, indicates the pattern will continue strengthening through the end of the year.
Global Effects and Broader Climate Patterns
El Niño’s influence extends beyond the Pacific. The pattern is associated with increased hurricane activity in the Pacific basin, higher global temperatures, and disrupted weather patterns worldwide, including droughts and flooding in various regions.
The CPC emphasized that while the likelihood of impacts consistent with El Niño is higher with a strong event, such outcomes are not guaranteed. The agency’s report cautioned that regional variations and other climate factors could influence the final effects.
What Is El Niño?
El Niño is a natural climate cycle characterized by the periodic warming of surface waters in the central and eastern tropical Pacific Ocean. The phenomenon was first observed by South American fishermen in the 1600s, who noted unusually warm waters near the coast around Christmas, leading to its name—"El Niño," meaning "The Little Boy" or "Christ Child" in Spanish.
The cycle alternates with La Niña, a cooling phase, and both are part of the broader El Niño-Southern Oscillation (ENSO) system, which plays a key role in global weather variability.