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Rainmaker

All eyes to the sky as a once-in-a-generation El Niño gathers strength

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A much-belated El Niño is coming—the first in 18 years—and it may be the strongest since 1950, when oceanographic monitoring began. "It's right on schedule," says Nate Mantua, a climate scientist for the National Oceanic and Atmospheric Administration's (NOAA) Southwest Fisheries Science Center.

By November, "temperatures in Southern California [were] about 5 degrees Celsius warmer than normal, or almost 10 degrees Fahrenheit warmer than normal," says Mantua. "Local waters are 5.5 degrees Fahrenheit above average, or in the low- to mid-60s, depending what the wind is doing."

There were hopes for drought-beating rain last winter, but instead we got the opposite: barely three inches of rain fell in Santa Rosa between January and March of this year. Petaluma got about four inches of rain over that same period.

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It was the Great El Niño Fizzle, sparked by the promise of increased ocean temperatures but extinguished by the trade winds which, in an El Niño event, need to slacken so all that warm water will slosh back to our side of the Pacific.

While there are no sure things, this year looks different. Surfers are psyched for a wave-generating El Niño. Organizers of Half Moon Bay's Titans of Mavericks big-wave surf contest have already been printing T-shirts that say "El Niño Is Coming," and coastal residents are rightly excited for larger than average swells in the coming months.

The oceans are warming, the trade winds have already died down, and the usually bone-dry Atacama Desert in northern Chile and southern Peru is blooming—a telltale sign that El Niño is upon us. There's just one thing: if El Niño was, in fact, a boy child gathering strength inside the womb of the Pacific, his sonogram would be atypical, to say the least. Admittedly, there's that unmistakable band of warm water bulging along the equator—El Niño's hallmark—but there are also large masses of warm water, creatively dubbed "the warm blob," extending, as we have never seen before, from the coastal United States and Mexico to as far north as Alaska.

"We've got this incredible warming of the higher latitudes of the Pacific Ocean," says Mantua, "and ocean temperatures have been record-high for the last two years. That makes this year unlike anything in our historical record."

El Niño was on everyone's mind on Dec. 3 when State Sen. Mike McGuire and Assemblyman Jim Wood held a hearing at the Steele Lane Community Center in Santa Rosa to talk about the ongoing shutdown of the California Dungeness and rock crab fisheries. Both species are victims of the blob, which spurred an algae bloom this year of unprecedented proportion that toxified the crab with high levels of domoic acid.

The backdrop at the big crab meeting was what scientists and elected officials are calling the emergent "new normal" in the Pacific Ocean. Though nothing is certain in these weird new waters, "if El Nino shows up in force as predicted, the blob will dissipate," said Catherine Kuhlman, executive director for ocean and coastal policy at the California Ocean Protection Council.

Kuhlman cited a litany of unpleasant blob-related trends at the crab conference that included many marine mammal deaths—sea lions are taking a hit—and unusual species' washing up on the beaches. "The ecosystem is shifting in response to the climate," Kuhlman told the committee and packed room of commercial crabbers who had journeyed from around the state for the event.

Kuhlman warned that, despite whatever benefit a wicked winter El Niño might have on breaking up the blob, "it's highly likely that we will have more of the algae blooms" in coming years.

"We don't know if it's climate change, the blob or El Niño, but the oceans are changing, and they are changing fast," said Eric Sklar, who sits on the California Fish and Game Commission.

The anomalous blob is raising many questions about climate change and our future—including what this year's El Niño winter will be like. Warmer oceans mean stronger storms and increased odds of above-average winter precipitation. But just how much rain is the boy-child planning to bring us? It is enough to replenish our parched land? Will it unfold slow and steady like applause or come in fits and torrential downpours, unleashing landslides, floods and hurricane-force winds, like the ones that tormented California's not-so-distant past?

"We know that no two El Niño events in the past have been the same," Mantua says, "even though a lot of attention is being put on what happened in [the] 1997–98 and 1982–83 [El Niños], because of similarities in the strength of this event to what those two events had. But there is no guarantee that we'll see a repeat of all of the things that might stand out in people's memories. Odds are there will be some surprises."

Even with advanced technology—which includes some 70 buoys moored in the depths between Japan and the California coast—climate prediction is a field riddled with unknowns, probabilities and conservative estimates. The saying goes, climate is what you predict and weather is what you get. But one thing is certain: it's going to rain this winter. Possibly a lot. And maybe in a way Northern California hasn't seen in decades.

Stormy Past

In early January 1982, a giant storm sat over the Bay Area and much of the California coastline. The rain began to fall during the last quarter of the NFL championship game between the San Francisco 49ers and the New York Giants, pouring through the night and into the next day. It was one of the most notorious California weather events of the 20th century, reports the Western Regional Climate Center (WRCC), a repository of historical climate information which uses data from the National Weather Service. The center reports that the '82 storms brought "high wind, heavy rain and heavy snowfall across all of California. This led to direct wind damage, higher tides, immediate flooding to coastal and valley locations, mudslides in coastal mountain areas, record snowfall in the Sierra mountains, and resulting spring snowmelt river flooding."

READING THE SIGNS  Warm bands of water have already amassed near the equator, evidence that El Niño weather patterns are likely.
  • READING THE SIGNS Warm bands of water have already amassed near the equator, evidence that El NiƱo weather patterns are likely.

The '82–83 El Nino left lots of wreckage, along with record rains and snowstorms: "Thirty-six dead, 481 injured, $1.2 billion economic losses, including 6,661 homes and 1,330 businesses damaged or destroyed," reports the WRCC.

They still talk about the weather events down in hard-hit Santa Cruz, especially scientists in the South Bay who beheld its wrath. "All you saw were trees sticking out and cars and pieces of houses, and it was right after Christmas, so there were Christmas decorations, and there were 10 people buried under it all," says Gary Griggs, professor of earth and planetary sciences at UC Santa Cruz, where he's taught since 1968. He was the first geologist on the scene the morning after the storm. "One woman survived," recalls Griggs. "She grabbed onto a tree as it went through her house at one in the morning."

More recently, in the winter of '97–98, massive flooding claimed 17 lives in California. East Palo Alto was one of the hardest hit cities in the Bay Area, as the San Francisquito Creek overflowed and damaged a reported 1,700 homes. Many were trapped inside, as all that surrounded the exteriors were lakes of muddy water after a steady month of rain. Those were El Niño years, which is a level this winter doesn't need to create dire consequences. "You don't have to have an El Niño year to have a really devastating winter," says Griggs.

According to a study published in the Journal of Coastal Research, about 76 percent of the storms between 1910 and 1995 that caused significant erosion and structural damage along the California coast occurred during El Niño years. We still don't really know why it happens, but when the trade winds—which normally blow toward the equator from the northeast and southeast—die down, it allows the warm water in the western Pacific to flow back toward the coast of South America and then up the coast.

"The first thing it does is change the climate on opposite sides of the Pacific," says Griggs. That means drought in places like the Philippines, New Guinea and parts of Australia, as well as heavy rainfall in the eastern half of the tropical Pacific. Some of these shifts are already happening, according to Mantua.

HIGH WATER EVERYWHERE If the deluge comes, Russian River communities will likely feel the brunt of the storms.
  • HIGH WATER EVERYWHERE If the deluge comes, Russian River communities will likely feel the brunt of the storms.

"Right now, the Atacama Desert in southern Peru and northern Chile is blooming," Mantua says. "They've had lots of rainfall the last couple of months, and that's a part of the world that has some of the driest deserts on earth in the absence of these El Niño periods. It can go years without any appreciable rain at all." Mantua notes that the same is true for the Galápagos Islands.

During El Niño winters, which typically peak in December and continue through January and February, periods of active storm development at the same latitude as Central and Southern California have sent storms barreling into the West Coast, says Mantua. This happened in the '82–83 and '97–98 El Niño years, but we have also had lots of storms like this in some non–El Niño years, he points out.

One concern is that the ominous warm blob could potentially add fuel to storms as they develop in their breeding ground between Hawaii and the Aleutians. "When we have big storms that do develop and move across that water," Mantua says, "they're going to have strong winds and they're going to evaporate a lot of water off that surface. They're going to cool that warm blob, but in the process, they're going to fuel themselves up. So I do think that our storms are going to be warmer and stronger than they otherwise would be without that vast area of warm water."

Coupled with elevated sea levels typical of a warmer ocean, the more direct westerly wave approach of El Niño winters delivers an extra blow, and potentially vast flooding.

Thirst for Rain

El Niño isn't synonymous with rain, though four out of the last six strong El Niños brought wet winters to California, Mantua says. But NOAA's Climate Prediction Center is calling for "increased odds" of a wet winter in Northern California; there's a one-in-three chance, and a less than one-in-three chance for a dry winter. And while the odds for a wet winter increase in Southern California, the Gulf Coast and Florida, there's just a 5 to 10 percent shift in the odds for a wet winter for the central and northern coast, Mantua says. "It's pretty subtle," he says, "but that is the nature of climate forecasting."

Would a wet winter end the drought?

"While the precipitation outlook suggests good news for California, one season of above-average rain and snow is unlikely to erase four years of drought," says Mike Halpert of NOAA's Climate Prediction Center. "The drought outlook shows that some improvement is likely in Central and Southern California by the end of January, but not drought removal. Additional statewide relief is possible during February and March."

The '82–83 and '97–98 El Niño months did bring lots of rain to the area, so there is hope that this year's El Niño might be the drought-buster. The headline-grabber from '98 was in parts of Marin County, which got up to 90 inches of rain that year. Many cities and towns up and down the coast, and inland, experienced a doubling, or more, of their annual rainfall averages in '97–98, according to data from the National Weather Service.

"There was good snowpack in the Sierra, and if we had a repeat of those kind of winters, it would definitely put a dent in the drought," says Mantua. "It wouldn't wipe out all of our water-supply deficit, it wouldn't recharge all of the ground water that's been pumped out in the last four years and the last dozens of years, but at least it would help refill reservoirs and recharge our soils and get a snowpack established again in the mountains."

El Niño was identified by fishermen in Peru and Ecuador as far back as the 1600s, not so much for its weather patterns as for its negative impacts on fishing. The warm waters shut down nutrient-rich upwelling, halting the plankton bloom and subsequently breaking the entire food chain. But El Niño's warm water can also mean weak upwelling in local waters too, which could mean poor reproduction this year for Dungeness crab, which are also being plagued by the blob's algae bloom of toxic domoic acid.

The warm water isn't great for Pacific salmon either, Mantua says, which thrive in cold, upwelled water high in nutrients and a productive plankton community that includes lipid-rich copepods and other crustaceans like krill.

"During these warm periods we know that it can be stressful for top predators, including salmon, seabirds, sea lions and seals," says Mantua. Salmon released from hatcheries, which produce most of the salmon caught off the coast of California, are usually fished after they've been in the ocean for two or three years, Mantua says, "so it doesn't have such a big impact on the season that you're in, but two or three years down the road."

Similar to past El Niño years, bluefin tuna, opah or moonfish, and bonito—marine life typical off the coast of Southern California—are all currently swarming area waters.

Since the last El Niño, the Bay Area has experienced almost two decades of relatively mild winters, and Griggs points out that only a small portion of today's residents were even here to experience the full wrath of an intense storm season.

"It's like all earthquakes aren't the same—all floods aren't the same, and all El Niños are not the same. I'm not sure if people fully understand that," says Griggs. "I think, in terms of flooding, what people are doing is trying to clean out storm drains and get sandbags ready and make sure your roof gutters are clean, which helps the water get out faster." Even so, "You can't stop sea levels from rising and you can't stop the waves from coming."

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