Unknown Artist. Christ Child with Passion Symbols, late 17th century, Peru. Oil on canvas, 39 1/8 x 31 3/4in. (99.4 x 80.6cm) frame: 44 11/16 x 37 3/8 x 2 1/8 in. (113.5 x 94.9 x 5.4 cm). Brooklyn Museum, Gift of Elizabeth Clare, 64.207. (Photo: Brooklyn Museum)
The Christ Child holds the world in his left hand and wears the forecast on his apron.
Dale Alan Cox is a retired U.S. Geological Survey project manager with roots in an early American utopian experiment. He writes about uncertainty, authority, and how we try to make sense of the forces that shape our common future.
August 3, 2026
In the autumn of 1997, Ants Leetmaa came to the USGS California Water Science Center in Sacramento carrying a forecast and looking for an audience.
Director of NOAA’s Climate Prediction Center, he was an Estonian-born oceanographer with none of the obvious gifts of a carnival barker. The equatorial Pacific had warmed with astonishing speed. Trade winds had slackened. A gigantic lens of warm water was moving east beneath the surface, visible to satellites, buoys, ships and the new coupled models. By summer, the scientists knew they were watching one of the strongest El Niños ever measured.
What they did not know was what it would do to California.
El Niño could shift the odds toward a wet winter, especially in Southern California. It could not tell Leetmaa how many atmospheric rivers would arrive, where they would make landfall, whether they would fall as rain or snow, or whether California would flood at all. He had a strong ocean signal and an unfinished weather forecast.
He went before the cameras anyway.
I saw him again in Santa Monica, at an event connected with Senator Barbara Boxer, amid the growing hoopla. For years I remembered his confidence. I see something slightly different now. Leetmaa had not outrun the science, but he had walked it to the edge of the stage. He was asking the public to take seriously a future that remained largely unresolved.
Was that foolhardy? No. But it was institutionally audacious. If he waited for certainty, the forecast would arrive too late to be useful. If he spoke early and the storms missed, El Niño would become a punchline, perhaps taking seasonal forecasting down with it.
The comedians got there first.
By fall, El Niño had become a member of the late-night cast. Jay Leno and David Letterman worked it over. On Saturday Night Live, Chris Farley appeared bare-chested in a cape and wrestling mask. “I am El Niño,” he announced. “All other tropical storms must bow before El Niño.” It was funny, which was the trouble. A vast exchange of heat between ocean and atmosphere had been reduced to a large man in tights.
Then came El No-Show. The forecast had arrived too early for the weather. Each dry day became evidence against it. The public had been told that something exceptional was coming, but not what to do with the interval before it came. We are poor custodians of intervals. We fill them with ridicule.
The storms of 1997–98 did come. California’s wet season brought destructive surf, floods, landslides and loss of life. It also brought CALJET aircraft into Pacific storms, where Marty Ralph and his colleagues measured the long, concentrated corridors of vapor we now routinely call atmospheric rivers. The old Pineapple Express acquired instruments, vertical profiles and a place in the physics.
Leetmaa had not predicted each storm or where every plume would land. He had done something both more modest and more audacious: months ahead, he shifted the odds toward a wet California winter and attached his name to it.
I saw him a third time the following June, at the National Oceans Conference in Monterey. President Clinton and Vice President Gore were there, along with people who had spent their careers trying to get the country to notice the ocean. At the Monterey Bay Aquarium, Leetmaa and I slipped off to the side while Gore shook hands and spoke in front of the jellyfish. They drifted behind him, pale and self-illuminated, while the cameras worked.
Leetmaa and I were not the attraction. But standing there, I began to understand the choreography. Science could spend years building an observing system and months constructing a forecast. Then everything had to pass through a few minutes of political theater. The uncertainty remained; only the microphone made it sound smaller.
I had seen the same thing at the Lake Tahoe Presidential Forum: scientists carrying years of work into a brief public moment, with politicians, cameras, and an extremely narrow opening in which something useful might happen. Monterey helped set the course for the work I later did at USGS. I was learning to pay attention not only to the science, but to the room around it.
Years later, I often saw science writer John D. Cox in the press room at American Geophysical Union meetings in San Francisco. I do not remember telling him that I had crossed paths three times with the man in the final chapter of his 2002 book, Storm Watchers.
Cox called the chapter “Out on a Limb.” After Franklin and his kite, after Bjerknes and the Southern Oscillation, after Lorenz and the discovery that small differences can unmake a forecast, he ended with a living scientist willing to attach his name to a future that had not happened. The instrument had changed from kite string to supercomputer. The limb remained.
Nearly three decades later, the Pacific was warm again. By July 2026, NOAA said El Niño was underway and likely to become very strong. Daniel Swain noted that the Niño 3.4 region was already warmer in absolute terms than ever observed at that time of year, with models carrying the event toward the upper edge of the modern record.
It was a massive El Niño forecast. It was not a California flood forecast.
El Niño loads the dice of the climate system; it does not dictate the throw. Even the strongest events do not deliver their textbook effects everywhere. Atmospheric rivers are weather, not obedient tributaries of an index measured along the equator. Their number, track, temperature and timing matter. So does the snow already on the Sierra when warm rain arrives.
California has another great flood against which every new one is measured, and it refuses to fit neatly into the El Niño story.
During the winter of 1861–62, storms worked over the West for weeks. Snow came, then rain, then warmer rain on snow. Rivers escaped their banks. Sacramento became an island; the Central Valley, an inland sea. The largest flood in the state’s written history survives as military reports, newspaper accounts, high-water marks, diaries, tree rings, layers of mud and measurements taken by a few observers. At the foot of Market Street in San Francisco, Thomas Tennent kept watch.
Tennent made mathematical and nautical instruments for a raucous new port crowded with miners, merchants and ships. He also kept a rain gauge. His observations, begun in 1849, became San Francisco’s earliest continuous precipitation record. For the 1861–62 season, he measured 49.27 inches, more than twice the previous season.
In 1873, George Davidson stood before the California Academy of Sciences with twenty-three years of Tennent’s observations plotted in graphical order. Westerners said the largest rivers ran high about every ten years; others assigned California’s floods an eleven-year cycle to match the sunspots. Davidson displayed the chart to refute the claim. From this record alone, he said, no periodicity could be predicted. The series contained the great spike of 1861–62 and still could not say when the water would return.
The record has not become tidier with age. Cary Mock’s work shows how treacherous reconstruction can be. Instruments moved. Observation times changed. Newspaper tables were copied, rounded, or set in type incorrectly. A thermometer reading without its exposure, hour, and location can be more artifact than atmosphere. The farther back we look, the more the climate record resembles an old family story: parts exact, parts missing, every surviving detail forced to carry too much weight.
Mock is emphatic on one point: 1861–62 was not an El Niño winter. Another possibility hangs more faintly over the record. Dubbi volcano erupted in what is now Eritrea in May 1861, and Mock noted that others, including Larry Schick, have wondered whether its aerosols influenced the atmospheric conditions preceding the flood. It remains an unpublished and unproven hypothesis. There may be no causal line at all.
Dubbi is imperfectly observed. The winter across the ocean is imperfectly observed. We are trying to reconstruct one moving fluid from traces left in another.
Davidson had reached for the ocean too. Any law of rainfall, he argued, would be complicated and masked by the influence of great currents. He chose the wrong one: the Kuroshio runs along the western edge of the Pacific and does not govern California’s wet winters. But he had the shape of the problem. California’s rain is coupled to a distant ocean across a delay, and no gauge on Market Street could recover it.
Davidson wrote the specification in 1873 and knew he could not fill it: comprehensive observations over great reaches of earth and ocean, each station understood in relation to the whole. Filling that order took a century and built a planetary nervous system of standardized instruments, ships, radiosondes, satellites, drifting buoys, supercomputers and scientists able to recognize an oscillation spanning the Pacific.
Tennent had the flood without the forecast. Leetmaa had the forecast without the storms. The observing system had finally coalesced. It still could not tell California exactly what would happen.
And Leetmaa still had to decide whether to speak.
That problem followed me through the rest of my career. ShakeOut was never only an earthquake model, any more than ARkStorm was only two historical storms stitched together and set loose in modern California, or HayWired only a rupture on the Hayward Fault. A scenario is a temporary room large enough to admit the future. Scientists, utilities, businesses, hospitals, governments and neighborhoods enter with different languages and leave, if it works, having imagined the same day.
Later work by Xingying Huang and Daniel Swain showed why ARkStorm has grown more urgent. In a warming climate, California’s megastorm risk rises sharply, and runoff can grow faster than precipitation alone would suggest. Their simulated megastorms were strongly associated with moderate or strong El Niño conditions. That does not turn 1862 into an El Niño event. It tells us that the El Niño now growing across the Pacific deserves attention before its storms acquire names.
Michael Dettinger has spent much of the intervening time explaining California’s narrow bargain. A few large storms supply a remarkable share of the state’s water. If they miss, reservoirs and aquifers decline. If they arrive together, or arrive warm over deep snow, the same water becomes a flood. The blessing and the threat are not two systems. They are the same current at greater volume, arriving warm over deep snow.
I think now that Leetmaa made the right wager. Not because the storms eventually proved him right. Results can flatter a reckless forecast as easily as they can vindicate a careful one. He was right because the signal was strong, the consequences mattered, and waiting would have consumed the only thing his forecast could give us. Not certainty. Time.
We can walk the levees, look hard at reservoir operations, make sure the phones work when the water rises, and watch the snowline as carefully as the Niño index. We can bring atmospheric river researchers, water managers, utilities, counties and communities into the room before the chairs are wet.
Or we can make jokes until the rain starts.
El Niño means the Christ Child because Peruvian fishermen recognized its warming near Christmas. The name has always meant arrival: a change in the water first noticed by people whose lives depended on noticing it.
The Christ Child is returning. The ocean and atmosphere will assemble the event without our consent. What they cannot assemble is the room where a forecast becomes a decision.
Leetmaa went looking for that room in 1997. We should find it before the chairs are wet.
Sources and author’s notes
This is an essay, not a technical report. The sources below support its principal scientific and historical claims. Michael Dettinger has confirmed that he was not part of the 1997 Leetmaa engagement; he enters the story later through atmospheric-river science and ARkStorm. The Sacramento, Santa Monica, Monterey and AGU passages are the author’s recollections.
Barnston, Anthony G., et al. “NCEP Forecasts of the El Niño of 1997–98 and Its U.S. Impacts.” Bulletin of the American Meteorological Society 80, no. 9 (1999): 1829–1852.
Climate Prediction Center. “ENSO Diagnostic Discussion.” NOAA/NWS, July 9, 2026.
Cox, John D. Storm Watchers: The Turbulent History of Weather Prediction from Franklin’s Kite to El Niño. Wiley, 2002. See chapter 28, “Ants Leetmaa: Out on a Limb.”
Davidson, George. “The Probable Periodicity of Rainfall.” Proceedings of the California Academy of Sciences, vol. V (1873).
Dettinger, Michael D., et al. “Atmospheric Rivers, Floods and the Water Resources of California.” Water 3, no. 2 (2011): 445–478.
Huang, Xingying, and Daniel L. Swain. “Climate Change Is Increasing the Risk of a California Megaflood.” Science Advances 8, no. 32 (2022): eabq0995.
Leetmaa, Ants. “Seasonal Forecasting.” Bulletin of the American Meteorological Society 84, no. 3 (2003): 331–332.
Mock, Cary J. “Some Comments on Reconstructing the Historical Climate of California, USA.” Il Nuovo Cimento C (2006): 55–63. The possible Dubbi connection is described here only as an unpublished and scientifically unproven hypothesis discussed by multiple people, including Larry Schick, as clarified by Mock in private correspondence, July 2026.
Ralph, F. Martin, et al. “Satellite and CALJET Aircraft Observations of Atmospheric Rivers over the Eastern North Pacific Ocean during the Winter of 1997/98.” Monthly Weather Review 132 (2004): 1721–1745.
Swain, Daniel L. Weather West virtual weather and climate office hour, July 2026. Discussion of Niño 3.4 temperatures, the relative oceanic Niño index and multi-model forecasts begins at approximately 46:38.
Tennent, Thomas. San Francisco rainfall observations, 1849 onward, as reproduced in early California climatological records and later federal compilations