El Niño is emerging earlier than expected in the Pacific Ocean, raising the possibility that it will become a historically strong El Niño, or a rare “super” El Niño, by fall or winter.
That’s according to the latest information just released by NOAA’s Climate Prediction Center, which says El Niño’s peak strength will be strong or very strong two-thirds of the time.
El Niño is a natural climate cycle that occurs when the tropical Pacific Ocean warms enough to cause changes in wind patterns throughout the atmosphere, which have ripple effects on weather conditions around the world.
Droughts and heatwaves are raging in some regions, raising wildfire risks and water supply concerns, while others are inundated by flood-like rainfall. El Niño’s widespread effects could also disrupt the Atlantic hurricane season. On a larger scale, human-induced climate change will cause global temperatures, which are already rising, to soar even further. All of these effects become more likely as El Niño conditions strengthen.
El Niño occurs approximately every 2 to 7 years and lasts 9 to 12 months. Its strength is measured by how much warmer-than-average water temperatures near the equatorial Pacific Ocean rise, typically reaching its peak during northern hemisphere winter.
A weak El Niño event occurs when temperatures rise more than 0.5 degrees Celsius above average for an extended period of time. To be considered a very strong El Niño or Super El Niño, water temperatures must be at least 2 degrees warmer than average.
Average water temperatures are currently just below the 0.5 degree threshold, but are expected to exceed that threshold by next month, according to the Climate Prediction Center’s monthly update released Thursday. This is a notable change from last month’s update, which favored neutral conditions, neither El Niño nor its colder counterpart La Niña until June.
After that, there is a possibility that the El Niño phenomenon will become stronger from summer to autumn. The chance that it will continue into winter has increased to 96%, making it almost certain.
Confidence is growing because large amounts of warm water have accumulated deep in the central and eastern equatorial Pacific Ocean in recent weeks. This water eventually rises to the surface, causing El Niño, which continues to intensify from there.
But while forecasters are becoming more confident that El Niño is occurring, “there remains considerable uncertainty about the strength of El Niño’s peak,” the Climate Prediction Center said.
Still, the CPC’s latest strength probabilities show that the chance of a Super El Niño occurring from November to January has increased to about one-third from one-quarter last month.
Michel Leroux, a scientist who leads CPC’s El Niño and La Niña forecasts, said if atmospheric changes continue to synchronize with changes in the tropical Pacific Ocean this summer, for example by weakening equatorial winds at the same time as ocean temperatures rise, the chances of El Niño becoming stronger increases.
Some generally reliable computer models indicate that this year’s Super El Niño could even be the strongest on record. This is the first Super El Niño since 2015-2016, which was the strongest in National Oceanic and Atmospheric Administration records dating back to 1950. Others include 1997-1998, 1982-1983, and 1972-1973.
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Although this El Niño phenomenon is not as strong as a super event, it is likely to remain strong. Typically, stronger El Niño events have a greater potential to influence global weather conditions, but their effects do not always unfold as expected.
The 2015-2016 Super El Niño lived up to its reputation for causing severe drought in the Caribbean, but it also failed to bring about the wetter-than-usual winter that Southern California is known for.
A more likely effect is global heat. The El Niño phenomenon raises the possibility that 2026 or 2027 will be the warmest in Earth’s history. The National Oceanic and Atmospheric Administration (NOAA) announced Monday that this year is already “very likely” to be the fifth warmest year on record, but that doesn’t yet account for the warming wildcard factor of El Niño.
Strong or super strong are the weather conditions that El Niño could affect early next year.
• Reversal of the hurricane season: Stronger El Niño conditions often result in more devastating storms in the Caribbean and tropical Atlantic, resulting in fewer tropical storms and hurricanes. The situation is the opposite in the central and eastern Pacific, which is typically crowded during hurricane season. This could mean further tropical threats to Hawaii and the southwestern United States, depending on where the storm tracks.
• The biggest impact in the U.S. is on winter: Warmer-than-average winters are typical across the northern U.S., western Canada, and Alaska, but there are still occasional bouts of severe cold. The southern tier of the United States is often wetter and cooler as the strengthened jet stream directs more storms in the region.
• Humidity, dryness, and extreme temperatures: In summer, monsoon rains decrease in India and Southeast Asia. Droughts are also often severe in the Caribbean. Warm, dry winters are typical in some regions of South and East Asia. In southeastern Africa, drought conditions could become more severe during the austral summer, which runs from December to February.
