An early bird El Niño has officially formed, and is likely to be strong, warp weather worldwide and give an already warming Earth an extra kick of natural heat, meteorologists announced Thursday.
The National Oceanic and Atmospheric Administration issued an El Niño advisory Thursday morning, declaring the arrival of the climatic condition. It may not quite be like the others.
This event — the first El Niño in four years — formed a month or two earlier than most El Niños do. There’s a 56% chance it will be considered strong and a 25% chance it reaches supersized levels, said climate scientist Michelle L’Heureux, head of NOAA’s El Niño/La Niña forecast office.
An El Niño is a natural occasional warming of part of the Pacific near the equator that shifts weather patterns across the globe, often by moving the airborne paths for storms. The world earlier this year got out of an unusually long-lasting and strong La Niña — El Niño’s flip side with cooling — that exacerbated drought in some parts the U.S. West and augmented Atlantic hurricane season.
Some of the wild weather of the past three years is likely to flip the opposite way, scientists said Thursday.
“If you’ve been suffering three years of a profound drought like in South America, then a tilt toward wet might be a welcome to development,” L’Heureux said. “You don’t want flooding, but certainly there are portions of the world that may benefit from the onset of El Niño.”
What does it mean for California? There’s no easy answer.
El Niños do not automatically guarantee wet weather for California. But historically, the stronger they are — and the warmer Pacific Ocean waters at the equator are — the more likely it is that the state will have a rainy winter season. And generally speaking, in strong or very strong El Niño years, Southern California has a higher chance of a wet winter than Northern California.
Since 1951, there have been 26 El Niño events. Of those, 11 have been weak, 7 moderate, 5 strong and 3 very strong. Overall, rainfall in Southern California averaged 126% of normal during all of them, and in the Bay Area it was 109% of normal, according to data compiled by Jan Null, a meteorologist with Golden Gate Weather Services in Half Moon Bay.
Two of the three very strong El Niños, in the winters of 1982-83 and 1997-98, were among the wettest in recorded California history, with massive Sierra Nevada snowpacks and major flooding. The third, in 2015-16, was something of a bust. Hyped as a “Godzilla El Niño,” that event did see big winter storms, but they ended up hitting Oregon and Washington instead, dashing hopes of breaking a California drought that didn’t end until big storms arrived in 2017.
Usually, an El Niño mutes hurricane activity in the Atlantic, giving relief to coastal areas in states from Texas to New England, Central America and the Caribbean, weary from recent record busy years. But this time, forecasters don’t see that happening, because of record hot Atlantic temperatures that would counteract the El Niño winds that normally decapitate many storms.
Hurricanes strengthen and grow when they travel over warm seawater, and the tropical regions of the Atlantic Ocean are “exceptionally warm,” said Kristopher Karnauskas, associate professor at the University of Colorado Boulder. So this year, NOAA and others are predicting a near-average Atlantic hurricane season.
In the past, a strong El Niño has led to record global warmth, like in 2016 and 1998. Scientists earlier this year had been saying next year is more likely to set a record heat, especially because El Niños usually reach peak power in winter. But this El Nino started even earlier than usual.
“The onset of El Niño has implications for placing 2023 in the running for warmest year on record when combined with climate-warming background,” said University of Georgia meteorology professor Marshall Shepherd.
El Niño hits hardest in December through February, shifting the winter storm track farther south to the equator. The entire southern third to half of the United States, including Southern California, is likely to be wetter in El Niño.
The U.S. Pacific Northwest and parts of the Ohio Valley can go dry and warm, L’Heureux said.
Some of the biggest effects are likely to be seen in a hotter and drier Indonesia and adjacent parts of Asia, L’Heureux said. Also look for parts of southern Africa to go dry.
On the other hand, drought-stricken countries in northeast Africa will welcome beneficial rainfall after enduring drought conditions for several years due to prolonged La Niña events, said Azhar Ehsan, associate research scientist at Columbia University.
Some economic studies have shown that La Niña causes more damage in the United States and globally than El Niño.
One 2017 study in an economic journal found El Niño has a “growth-enhancing effect” on the economies of the United States and Europe, while it was costly for Australia, Chile, Indonesia, India, Japan, New Zealand and South Africa.
But a recent study says El Niño is far more expensive globally than previously thought, putting damage estimates in the trillions of dollars. The World Bank estimated that the 1997-1998 El Niño cost governments $45 billion.
The United States also faces hazards from El Niño despite some benefits. Ehsan noted that the increased rainfall heightens the risk of landslides and flash flooding in these some areas. “While El Nino brings benefits in terms of water resource recharge, it poses certain hazards that need to be considered and managed,” he added.
Associated Press reporters Seth Borenstein and Isabella O’Malley contributed to this report.
