by SAN DIEGO — In 1983, El Niño caused historic flooding in parts of Southern California, leveling sections of fishing piers and inspiring some to ride submerged streets on surfboards. In 1998, it returned and covered the regional mountains with snow during May.
For the collective mind of Californians, the climate phenomenon, defined by a warmer-than-normal sea surface moving east along the equatorial Pacific, is shaped by those traumatic and powerful winters with record rainfall.
But because some Earth scientists see a bit of 1983 or 1998 in next winter’s strong El Niño, they may be neglecting a new reality: A stormy, wet El Niño from that time has not hit California this century.
Earth system sciences professor Jin-Yi Yu of the University of California, Irvine, whose doubts about a “Godzilla El Niño” predicted for 2015-16 were confirmed, believes that the phenomenon has permanently changed.
“Children in these respective centuries are different,” Yu said in a series of emails. “The recent El Niño and La Niña events have behaved differently than we initially expected.”
While Yu is once again a rare voice dismissing the chances of a wet El Niño in California this winter, many of the state’s most influential weather observers aren’t entirely opposed to his bearish outlook.
The National Oceanic and Atmospheric Administration said the current El Niño is “strong” by its measurements, which could translate into strong storms affecting parts of the state.
State climatologist Michael Anderson, who also expressed some doubt about the 2015 “Godzilla El Niño” predictions, has asked Californians to essentially be prepared for anything.
“Until better seasonal forecasts are available, California is preparing for extreme wet or extreme drought conditions,” he said by email.
This may be prudent in a meteorological world that sometimes seems upside down.
Although the 2022-23 season was designated as a La Niña year, generally drier and colder, the state received 141% of the average precipitation for the water year that ended Sept. 30, the California Department of Water Resources said. . The snowpack in the Sierra Nevada Mountains rivals that of 1983, he said.
How accurate are El Niño predictions?
Tim Barnett, the late marine geophysicist at the Scripps Institution of Oceanography at the University of California, San Diego, predicted the strong, stormy El Niño winter of 1997-98, a quantum leap for a weather world that is still 50-50 with 10 days. forecasts.
It was the first, last and only time an El Niño storm was successfully forecast for California. That season’s storms caused $850 million in damage to the state and doubled its normal rainfall, according to Golden Gate Weather Services meteorologist Jan Null.
Null, a retired senior forecaster with the San Francisco Bay Area office of the National Weather Service, said there have been 26 El Niño and 25 La Niña since 1950, and the vast majority of the former did not act like those in 1982- 83 or 1997-98. .
“The Kid is the Stephen Curry superstar of the game,” Null said, referring to the Golden State Warriors guard. “But sometimes someone else has a good night and has a bigger influence.”
Last winter’s Wet Girl, he said, “totally flipped the script.”
What are the chances of a rainy winter?
Anderson, the state climatologist, said an even number of El Niño’s this century have produced dry and wet winters. “El Niño alone does not always translate into wet conditions,” he said.
The Scripps Institute’s Center for Western Climate and Water Extremes puts the chances of a wetter-than-normal winter for most of California at essentially 50-50, though that’s based on historical data, not long-range forecasts.
A NOAA long-range forecast map from October shows equal chances of above- or below-average rainfall this winter for California’s southernmost coast, with the chances “leaning” in favor of above-normal rainfall for the rest of the southern California. and spreading to the Bay Area.
The state Department of Water Resources said last month that residents should prepare for “the possibility of another rainy season under strong El Niño conditions.”
Shang-Ping Xie, a climate science researcher at the Scripps Institute, puts the chances of a wet El Niño in California this winter at 2 to 1.
“We had a La Niña that lasted three years,” he said. “Two were dry and one was wet. “The probabilities are not that different from the typical results, which say that La Niña favors a dry winter.”
But in the two classic examples of stormy El Niño winters in California, the month of March was the hardest hit by rain, wind and damage.
“We think March is the time when the tropical ocean has the most influence on North America,” Xie said.
Are there other factors that affect the prognosis?
Although its behavior can be unpredictable, identifying El Niño is relatively basic and depends on a huge mass of water in the equatorial Pacific that, when consistently warmer than average, triggers the declaration of the phenomenon, usually during the winter.
The relative warmth of El Niño can affect atmospheric circulation along the equator and push a jet stream that normally points toward the Pacific Northwest southward, leaving that region drier and the Southeast wetter.
The absence of El Niño in 2015-16 led UC Irvine’s Yu to delve deeper into the possible causes, and today he believes other climate and man-made phenomena are affecting it.
He thinks global warming, in part, and possibly deforestation in Southeast Asia may have helped create a second patch of warm water adjacent to El Niño that may be thwarting its old ways.
This century, El Niño “has moved westward toward the central Pacific and has lasted longer, becoming multi-year events,” Yu said. “The Child has changed.”
Xie, the Scripps researcher who believes the odds favor a stormy El Niño, nevertheless believes there are influences on the phenomenon triggered by climate change. For example, he said, the warming of the ocean around the surface that defines El Niño is also warming in the long term.
What will happen when that heat becomes the new foundation for a wider swath of ocean?
“If this pattern continues in the future, then the influence of El Niño will strengthen,” Xie said.
He believes El Niño data and computer models may not be up to par.
“There are many questions we still have to answer,” he said.
Null said all eyes are on academia to help determine what will happen with El Niño, particularly in the country’s most populous state, which is typically in its path.
“It’s a game of continuous learning,” he said. “We have evolved our understanding of El Niño, but then we complicated it when the atmosphere and oceans warmed.”
“Are we keeping up?” she asked. “I don’t know.”
This article was originally published on NBCNews.com
