Jul 13, 2023 - Energy & Environment

El Niño likely to be "moderate to strong" while roiling climate

Data: NOAA; Map: Erin Davis/Axios Visuals

El Niño conditions are only slowly gathering strength in the tropical Pacific Ocean, but the National Oceanic and Atmospheric Administration expects the event is likely to peak at a moderate to strong intensity by the fall and winter.

Why it matters: The natural climate cycle is already boosting global average surface temperatures and contributing to unprecedented extreme weather events. These trends are likely to be even more noteworthy into next year.

Driving the news: The latest El Niño update, from NOAA's Climate Prediction Center, shows that weak El Niño conditions continue to be present. Still, the air and sea are not yet fully marching in lockstep across the equatorial tropical Pacific Ocean.

  • Stronger air and sea "coupling," as meteorologists refer to it, would be required for the cycle to intensify.
  • This can occur quickly, however; the agency gives the El Niño greater than 90% odds of continuing through the Northern Hemisphere winter.
  • The NOAA puts the chances for a moderate-to-strong El Niño event during the November through January period at about 81%.

Yes, but: The new bulletin plays down the likelihood of a "historically strong" El Niño event this year, assigning the odds of such an outcome at one in five.

  • "At this point, we cannot entirely rule an event of that magnitude out, but I don't see a lot of support" for it in the observational and forecast data, meteorologist Michelle L'Heureux tells Axios in an email. She leads the group of scientists that monitor and forecast El Niño and La Niña.

Between the lines: In order to strengthen, the east-to-west flowing trade winds along and just north of the equator would need to reverse directions. Meanwhile, heavy tropical rains typically found across the Western Pacific would slide away from Indonesia and Australia, toward the Central Pacific.

  • So far, these trends have lagged the oceanic fingerprint for El Niño, but they do show an atmospheric signal of a weak event, NOAA reports.
  • These dynamics matter because the stronger El Niño becomes, the more significant the worldwide effects, including further elevating global average surface temperatures.

Threat level: Given the growing magnitude of human-caused climate change, it no longer takes a historically strong El Niño to yield a record warm year for the planet.

What's next: El Niño tends to have a lag between its peak intensity and the highest ocean temperatures. This likely means that 2023 will set a global temperature record that is then overtopped by 2024.

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