El Nino unlikely to fix California drought
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WASHINGTON, Oct. 1, 2014 - The likelihood of an El Niño event developing over the Pacific Ocean is still up in the air, but if the weather pattern develops, there's little chance it will provide enough rain to end one of the worst droughts in California history.
The Climate Prediction Center (CPC) at the National Oceanic and Atmospheric Administration (NOAA) in September issued an El Niño watch, saying there is s 60-65 percent chance that the weather event will occur this fall or winter in the Northern Hemisphere. The same agency said in March that there was potential for a “very strong oceanic Kelvin wave,” which is a trigger of an El Niño event. That wave never materialized, and it is looking less and less likely that California will feel the benefits of added rainfall, meteorologists say.
Mike Halpert, the CPC's acting director, said previous suggestions that an El Niño event would result in heavy California rains may have been misguided.
“Every [El Niño] event is different,” Halpert said in an interview with Agri-Pulse. “So just because one place was wet during one event doesn't promise, doesn't guarantee that you will be wet [the next event].”
While it's obvious that California's drought problem wouldn't be fixed overnight, a traditional El Niño event could have brought above-average precipitation to the state, the biggest agriculture producer in the country. The system typically generates a winter season that is wetter than usual in the southern U.S., stretching from Southern California to the Florida's Gulf Coast. Inversely, El Niño triggers a dryer winter season in the northern half of the country, especially in the Northeast and Northwest.
El Niño is caused by trade winds that blow warm water from the Eastern Pacific Ocean west, causing monsoons in Southeast Asia. When those trade winds stop, the warm water resides along the South American coast, which alters the jet stream and forces Pacific storms over California. This same weather pattern caused devastating mud slides in California 1998.
Halpert said CPC will issue a new El Niño report Oct. 9, which will update the likelihood of an El Niño event occurring this season. There are differing degrees of El Niño strength, and experts are predicting a weak or mild El Niño event this year, if one happens. Simply stated, if an El Niño event happens, it won't be strong enough alone to fix the California drought. Even so, Halpert said California could at least be grateful the state isn't experiencing a La Niña, which would create drier conditions in the same areas dampened by an El Niño.
“So you could look at it as just the knowledge or the absence of La Niña as a good sign,” Halpert said. “A fairly strong, '97 or '98 type of El Nino would have been a better sign, but at least we're not expecting to deal with La Niña this year.”
USDA Meteorologist Brad Rippey said several precipitation events spread out over “several months” is the best-case scenario for California to escape the drought.
“I think the best we can really hope for though is if you've got an above-average year (for precipitation) and you start to claw your way out of drought,” Rippey said. “After three years, it's going to take a long time to recharge groundwater supplies, and it's going to take a long time to fill reservoirs.”
Rippey said the agricultural production lost in California could be made up by favorable conditions in most of the Eastern two-thirds of the U.S. where in most places the last traces of the 2012 drought are gone. Rippey said 15 years' worth of “drought-creating weather patterns” should have caused some alarm in the western U.S., but that California's current crisis should serve as a warning to the rest of the country to consider all factors that go into water usage.
“You also have to realize that populations continue to increase especially in California and the Sunbelt, and so we have a lot of competing interest for a limited resource -- water,” Rippey said. “A lot of these water compacts were written at a time when water was more plentiful and populations were much lower, so I think it's just an eye opener for the West that water usage patterns have to change and maybe some of the rules have to change to be able to adapt to changing populations and changing climate.”
El Niño, or “boy” in Spanish, refers to the Christ child. The weather phenomenon takes its name from this because the periodic warming in the Pacific near South America usually occurs around Christmas.
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