It’s Official: El Nino’s Destructive Act Is Gone

El Nino--the little kid who caused so much trouble--is gone.

Blamed for last year’s unusually wet weather in Southern California, catastrophic floods in the Midwest and punishing droughts in Australia, the puzzling weather phenomenon named for an innocent child has finally come to an end, the National Weather Service says.

Forecasters say that should mean a gradual return to normal weather conditions--good news for the residents of Malibu who learned the hard way last month that unusually heavy rains on slopes stripped of vegetation during brush fires could mean an onslaught of destructive mudslides.

“It appears that El Nino has ended,” Alan Basist, a meteorologist with the National Weather Service’s Climate Analysis Center in Silver Springs, Md., said Monday. “It apparently happened in December.”

What occurred then, he said, is that equatorial trade winds in the southern Pacific resumed their customary strong flow from east to west.

For more than a year--and perhaps as long as three years--these winds had been abnormally light, even flowing at times in the opposite direction, from west to east. Pushed by these unusual westerly winds, large bodies of warm water that normally circulate near Australia had drifted slowly east in what is called a Kelvin wave, pooling off the west coast of Peru.

In times past, this wave was detected by the abnormally small fish catches off Peru, where the warm current would deprive the coastal waters of nutrients normally brought to the surface by cooler currents from below. Coastal residents called the phenomenon El Nino, naming it for the Christ child because the storms it spawned were first observed around Christmastime.

More recently, the Kelvin wave has shown up on radar sensors aboard a satellite monitored by NASA. Because the warm water of the Kelvin wave is less dense than the cooler water surrounding it, it forms a bulge about six inches high on the surface of the Pacific--an altitude differential that the radar can detect.

Observations made as recently as November showed what the National Oceanographic and Atmospheric Administration had suspected: The bulge was still there. Armed with this information, forecasters predicted another abnormally wet winter for Southern California.

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But December turned out to be unusually dry, as did January and February. Asked about this, the satellite folks checked their instruments and found out, sure enough: The bulge was gone.

Asked why El Nino shows up every so often, then disappears, usually for eight years or so, Basist chuckled.

“There’s a lot of research on that, a whole lot of research,” he said. “People aren’t that sure yet.”

Curtis Brack, a meteorologist with WeatherData Inc., a Wichita, Kan.-based firm that provides forecasts for The Times, said that with El Nino safely out of the way, it looks as though precipitation in Southern California should be about normal for March and April, with temperatures a little above normal.

He predicted a high temperature at the Los Angeles Civic Center today of 79 degrees.