With apologies to Game of Thrones fans, there’s a new climate menace on the prowl: El Niño is coming.
New data released late last week added to the mounting evidence.
To be declared an official El Niño, surface water temperatures in the equatorial Pacific Ocean must warm by half a degree Celsius averaged over three months and maintain that level for five consecutive three-month periods. That’s an arbitrary definition, sure, but it gives us the ability to crunch the numbers on weather patterns that tend to associate with El Niños on a global scale.
Statistically, this time of year has the least predictability at any time all year. But peering below the ocean’s surface, water temperatures are already off-the-charts-hot. If that warm water makes it to the surface, the planet could be in line for one of the most intense El Niños ever recorded. That would be enough to shift weather patterns worldwide and make the next couple of years among the hottest we’ve ever known. Earlier this month I wrote that taking into account current forecasts, El Niño could be the biggest global weather story of 2014. The new data shows that forecast is still on track. And that means El Niño could officially begin in a matter of weeks.
Recently people have been tweeting me questions like: “Will El Niño destroy my family’s avocado plantation in Sweden?” or “Will El Niño finally banish the Eye of Sauron from the drought-stricken Mordor formerly known as Sacramento?”
While the answer to both of those questions is a qualified no, there are some parts of the world that have a relatively predictable weather signal when El Niño rolls around.
There have been only a handful of El Niño events in the last few decades, and in many cases it’s difficult to generalize based on such a small sample size. Only once in the last 30 years—1998 (see above animation)—were subsurface water temperatures as warm as they are now. Which makes forecasting even more difficult.
But by averaging all the recent El Niño events together, we can take a guess at the general trends for what the next few months might bring. (Since all the websites offering El Niño impacts seem to be based on a Microsoft Encarta CD-ROM from the late 1990s, I figured we needed an update.) Let this be your warning: Not all of these predictions will come to pass. Some surely won’t. Frankly, I’m overgeneralizing a lot of nuance here. The below should be read as a tilt of the odds, not a black-and-white forecast. But it’s grounded in the past, and given the current state of the ocean and atmosphere, it offers a good idea of how planet Earth might deal in 2014–15.
Here it is, your guide to the world on El Niño.
Anchorage: A warm, wet winter along the southern Alaska coast and a warm, dry winter in the interior. The Iditarod could have another rough go. One study shows that summer 2015 could be a big one for wildfires.
Seattle: A warm winter, and especially warm waters offshore, could be tough for the Pacific Northwest salmon. Past El Niños have induced dramatic declines in the population of salmon, which found themselves caught by surprise as they migrated back south to spawn.
Portland, Ore.: A warm and dry winter throughout the Columbia River basin. Oregon’s in a drought, too. It isn’t nearly as dependent on snowpack as California is, but river levels could drop and ski areas could have another rough go. Southern Oregon’s Mount Ashland didn’t even open at all this year, the first time in its five-decade history.
San Francisco: Depending on El Niño, rains could return to drought-stricken Northern California. Or maybe they won’t. There’s great news if you’re a Bay Area fisherperson: Tropical game fish like mahi, swordfish, and blue marlin have been spotted this far north during past El Niños.
Monterey: Coastal California is among the most susceptible places to landslides in the country. Heavy rains, like the ones that helped contribute to the Oso, Wash., disaster, could strike near here this winter.
Los Angeles: Car-bound Angelinos have another threat to worry about: potholes. During the last major El Niño, in 1998, a parade of pavement-crumbling storms helped skyrocket reports of bad roads by 400 percent.
This farm, in California’s Central Valley: In the midst of the state’s worst drought in half a millennium, agriculture in California is at the end of its rope. That has some farmers hoping for El Niño, which has been known to bring heavy rains and snow. Still, the deficits racked up over the last few years are so huge, even a deluge may not end the drought.
Boise, Idaho: With the jet stream’s energy often split between Alaska and Southern California in El Niño years, places in the middle like Idaho get the short end of the stick. Plan to ski elsewhere this coming winter.
Denver: Colorado Front Range snowstorms are significantly heavier during El Niño autumns and springs, though precipitation as a whole is roughly the same. A National Center for Atmospheric Research analysis shows a 20-inch snowstorm is roughly seven times more likely in an El Niño year than in a La Niña year. Neutral years—neither El Niño nor La Niña—are somewhere in between.
Texas: If this El Niño develops into a strong one, the Texas drought—nearly as severe as the one in California—could be a major beneficiary. Looking at past El Niños, a cool, wet winter in Texas is among the clearest signal in the United States, rainfallwise.
Kansas City, Mo.: If you’re like me, you’re already planning your World Series parties. If you’re a baseball player based in the Midwest, there’s a bit of a greater chance for rain during El Niño Octobers, so plan for rain delays accordingly. Teams with a deep bullpen, like, oh, this one, should fare better in the playoffs.
Chicago: This winter, folks in Chicago—near the epicenter of this winter’s polar vortex-fueled cold air outbreaks—would have probably sold their souls for a hint of spring. El Niño could be the savior they’ve been seeking: According to legendary weatherman Tom Skilling, Chicagoland winters are predictably mild when El Niño’s in force. That should reduce heating bills and incidence of snowball violence.