El Niño could help Nevada, California drought rescue
Conditions in the equatorial east Pacific are shaping up to produce the first El Niño in four years, with the phenomenon standing to make for a wet winter starting later this year and provide some relief to drought-parched Nevada and California.
Last week, the U.S. Climate Prediction Center issued an El Niño Watch after experts concluded there's a better-than-even chance an El Niño will develop during the coming summer or fall, potentially affecting the winter of 2014-15.
El Niños have produced some big winters for the Reno-Tahoe area in years past. As the region struggles through what seems certain to end up as the third abysmally dry winter in a row, that potential comes welcome to many.
"It's a little bit of hope to hang a hat on," said Kelly Redmond of the Western Regional Climate Center at Reno's Desert Research Institute.
El Niño is characterized by warmer-than-average surface water temperatures in the ocean west of South America. When one is established, El Niños tend to bring stronger winter storms into Southern and Central California. And if an El Niño is robust enough, it can bring heavy rain and snow to Reno and the Sierra as well.
There were the blockbuster El Niño years of 1982-83 and 1997-98, which produced copious rain and snow across the region. The last El Niño occurred in 2009-10, an event of moderate strength that produced an average snowpack for the Sierra.
"Historically the stronger the event, the greater the likelihood of a wet winter out West," said Mike Halpert, acting director of the Climate Prediction Center.
There's no guarantee an El Niño will develop, Halpert said. The El Niño Watch was declared after experts concluded there's now a 52 percent chance one will. An El Niño began to brew in 2012 and then shut off, with that winter — like the one now concluding — influenced neither by an El Niño or its opposite, a La Niña.
The last La Niña, characterized by cooler-than-average ocean surface temperatures in the east Pacific, occurred during the winter of 2010-11. La Niñas typically funnel big storms into the Pacific Northwest, but, like that year, can bring a big winter to Reno-Tahoe as well.
"These things can be fickle," Halpert said. "But the way things are evolving, and because we haven't had an El Niño since 2009-10, these are pushing the likelihood that an El Niño will develop."
Whether it's El Niño or La Niña, Reno-Tahoe is the pivot point for the climate phenomenon, with either offering a chance at wet or dry conditions here.
"The Reno area is like the fulcrum of a teeter-totter, with our region being in the middle," Redmond said.
Still, Redmond holds out optimism the coming year might produce some changes that will help.
"If it happens, are there prospects for relief? There could be," Redmond said. "It's not a panacea. It's not a given that it would be a drought-buster but it would probably increase the odds of getting some relief."
Big El Nino winters, Lake Tahoe snowpack
1982-83: 249 percent of average.
1997-98: 159 percent.
Moderate El Nino winters
2009-10: 105 percent.
2001-02: 104 percent.
Source: RGJ research.