Why it is likely too late for El Nino to save Southern California from drought

The tale of El Niño 2016 reads like two different stories.

In Northe Califoia, the weather phenomenon has delivered above normal rain and snow this winter. Not so in Southe Califoia, where rainfall is only half of normal for downtown Los Angeles.

Why the discrepancy? Climatologists have various theories but they are just that, theories. More importantly, time is ruing out on restoring Southe Califoia to above-drought rainfall levels, leading to a disappointing end to what many predicted would be a very rainy winter that would make a dent in the driest four years in state history.

“Once you get past April 1, the amount of rain we get on average decreases remarkably,” said Ken Clark, expert meteorologist with AccuWeather.com in Southe Califoia. “We are basically out of time to get back to normal (precipitation), that is, unless something really weird happens.”

While Clark came close to predicting a fifth drought year for Southe Califoia; others are saying not so fast.

“Don’t throw El Niño under the bus until the end of April,” said Bill Patzert, climatologist with NASA’s Jet Propulsion Laboratory in La Cañada Flintridge.

In the winter of 1982-1983, El Niño started late, producing the heaviest rains in March and April. While Patzert is getting heat for calling the 2015-2016 version a “Godzilla El Niño” since summer, he said on Monday it has performed as a late-bloomer like its predecessor in 1983, leaving a sliver of hope for tardy rains in March and April.

Patzert had predicted the brunt of El Niño would fall in February. Yet, Southe Califoia tued warm and dry. While rains hit Southe Califoia earlier this month and last weekend, the rainfall amounted to only 1.56 inches in downtown Los Angeles, the benchmark for rainfall totals in the region. Since Oct. 1, only 6.54 inches of rain fell, about 53 percent of normal, Clark said. On Monday, the ministorm dropped a scant 0.03 inches in downtown.

It would have to rain 6 more inches this winter just for Southe Califoia to get back to normal, he said.

“That is just not going to happen,” Clark added.

Starting Tuesday , a high-pressure ridge will chase away any hint of rain leaving suy skies through Sunday. Temperatures will reach 82 degrees in Los Angeles on Wednesday, according to the National Weather Service Oxnard/Los Angeles office.

“The ridge of high pressure is building into the West Coast,” NWS meteorologist David Sweet said. “That will assure the suy, drier warmer weather.”

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This El Niño did not behave like most large El Niños. It also got pushed around by a high-pressure ridge that shoved the jet stream to the north, sending what would have been local storms into Northe Califoia, Oregon and Washington.

In six months, Patzert said, Oregon and Washington went from severe drought to near normal.

“Seattle and Portland stole our rain,” he said.

This El Niño may have disappointed locally, but up north, it’s a hit. Since Oct. 1, precipitation at stations in Northe Sierra, Southe Sierra and the Tulare basin reached 131 percent of average, 115 percent and 109 percent, respectively, according to the state Department of Water Resources.

The snowpack averaged 92u2009percent of normal in the three combined regions of the Sierra as of Monday. Because Southe Califoia gets two-thirds of its water from the Colorado River and Northe Califoia, the newly layered snowpack will aid Los Angeles and other cities that buy imported water come late spring and summer. The DWR has increased allocations from zero percent last year to 30 percent.

“In terms of water management ... that is good news,” Patzert said. “For local water managers, it’s disappointing.”

As to why the majority of Pacific storms tracked north? Clark said other factors are at play, namely ocean winds and sea surface temperatures.

Patzert called the creation of high-pressure ridges — like the one bringing dry weather this week — a spoiler. Yet, even a rainy year would not retu reservoirs and groundwater basins to pre-drought levels. That will take four to five years of above average rainfall.

Clark said the current ridge will break up by Sunday, leaving the door ajar for storms to enter.

“We are not done with rain,” he said. “I almost guarantee there will be more rain in March.”

How much more? No one knows.

“Don’t throw in the towel yet,” Patzert said.