El Nino (142183)

Hopes are being heightened throughout the state that the mysterious, elusive El Nino weather pattern will wind its way northward along the Pacific Coast and bring needed rain. Climatologists with the California Department of Water Resources believe that the recent moisture in the state and inversion layers may foretell storms this summer that may help alleviate the state’s historic four-year dry spell.

Southern California this month has witnessed much more moisture and cloudy skies. San Diego had its wettest May in 94 years, and Los Angeles saw nearly four times its average rainfall. Even the Dodgers and San Diego Padres each had to delay a game because of rain. The Mojave Desert near the Antelope Valley is reportedly running as much as 5 degrees cooler than normal. El Ninos have been responsible for two of California’s wettest and most costly rainy seasons: the winters of 1982-83 and in 1997-98.

El Nino is the warming of Pacific Ocean waters along the equator—generally from Peru to the International Date Line—that causes changes to the atmosphere and can influence weather globally.

“Can one big year ease the drought conditions? Yes, it can,” said Michael Anderson, a climatologist with the department of water resources. “It can definitely replenish the surface storage and can have some benefit to a start to replenishing some of the groundwater.”

Last winter, California water officials said it takes about 75 inches in precipitation in the northern Sierra Nevada Mountains—a major source of the state’s water—to end the drought and to bring reservoir storage and runoff back to normal levels. However, Southern California’s traditional rainy season has produced practically nothing. Only 34.9 inches have fallen since February, considerably below the average of 50 inches.

“This drought is not a one-shot deal,” said Bill Patzert, a climatologist with the Jet Propulsion Laboratory in Pasadena. “Normally when a drought goes away, everything tends to go back to normal. This drought is different, because we’re living in a warmer world. It’s a world of declining snowpack, all of which will test water supplies for years. The warmer it is during the day, the more evaporation you see. It will take a lot more rainfall to come out of this drought.”

Last summer forecasters and scientists thought El Nino was forming in the Pacific, but the tricky weather pattern fooled them. They watched as it gradually faded out. But with record storms in Texas and Oklahoma the last few weeks, scientists have reason to believe that El Nino could make an appearance—exactly when is still anybody’s guess.

“There are a number of models, some which strongly point in the direction of an El Nino,” said Dan Cayan, a climate researcher for the Scripps Institution of Oceanography and the U.S. Geological Survey. Cayan explained that some El Nino years gave California extra-dry weather and only the strongest ones can be considered a reliable forecaster for above-average precipitation.

Even if the big rains do appear, officials at the state water board insist that Californians should not in any way ease up on current water conservation measures.