Bone-dry California remains on track to get a drenching this winter from the weather phenomenon known as El Niño, federal scientists said in new projections released Thursday.
The experts still believe “that this El Niño could rank among the top three strongest episodes” on record, bringing average or above-average rains to the entire state. Pacific Ocean temperatures driving the phenomenon aren’t expected to return to normal until late spring or early summer, adds the report from the National Oceanic and Atmospheric Administration’s Climate Prediction Center and Columbia University’s International Research Institute for Climate and Society.
“We expect it to remain strong through the winter,” Mike Halpert, deputy director of the Climate Prediction Center in College Park, Maryland, said Thursday.
El Niño is a disruption in the Pacific’s ocean temperatures and weather patterns over the Pacific.
“This is about 7 or 8 million square miles of overheated ocean directly south of us. That’s about two and a half times the size of the continental United States,” said Bill Patzert, a research scientist and oceanographer at NASA’s Jet Propulsion Laboratory in Pasadena. “And that very, very large pool of warm water is pumping tremendous energy into the overlying atmosphere and changing all the pieces on the weatherboard across the planet.
“If you’re doing long-range forecasting, in your career this is as close as you’ll ever get to a sure thing,” Patzert said. “It’s totally unanimous now: This thing is a monster and it’s here, so fasten your seat belt.”
Seasonal outlooks will be updated next week, Halpert said, and “my guess is that we still will give the best chance to see a wet winter in the southern part of the state, but we will probably still favor a wetter-than-average winter in the northern part.”
That’s important because most of California’s big reservoirs are in the state’s northern half, and they remain at only a fraction of their normal levels after four years of devastating drought.
For example, Lake Shasta is at half its historic average for this time of year; Lake Oroville is at 46 percent; Trinity Lake is at 31 percent; Folsom Lake is at 29 percent; and the New Melones Reservoir in the foothills near Jamestown is at 20 percent.
The rain the Golden State has seen since Oct. 1 has put a few Bay Area locales — including San Jose, Mountain View and Livermore — ahead of their normal precipitation levels while most of the region remains behind. Elsewhere around California, cities such as Salinas, Stockton, Fresno, Modesto and San Diego are ahead of normal for the past six weeks, while the Los Angeles area remains behind.
The Sierra Nevada’s snowpack, melt-off from which provides nearly a third of the state’s water, fell this year to its lowest level in at least 500 years, according to a study published in September by Nature Climate Change, a peer-reviewed British journal.
That’s just starting to change. Moderate to heavy precipitation fell recently in the mountains, and now the “snowpack is well above normal for this time of year in the Sierra Nevada and parts of Nevada where drought has seemed intractable,” according to a U.S. Drought Monitor report issued Thursday. But “areas where drought was more entrenched will need abundant precipitation to continue much farther into the wet season before any notable improvement could evolve,” the report added.
The recent rain and snow was due to a storm looping down from the Gulf of Alaska. So El Niño has yet to truly rear its head in California, and Halpert said the state should be careful what it wishes for.
“I do have some concerns that if we see the types of extremes we saw in ’97-’98 and ’82-’83. … there’s going to be a downside to it as well,” he said — and that means flooding, landslides and other weather-related chaos. “The rain probably won’t all fall gently enough to refill the reservoirs without causing some havoc.”
Josh Richman covers politics. Follow him at Twitter.com/Josh_Richman. Read the Political Blotter at IBAbuzz.com/politics.
