El Niño teased us for a while, but now it looks like the little guy has no intention of gracing us with his presence this winter. Without him, have our chances of a much-needed rainy year gone out the window?
Long-range forecasters seem to think so. They say that San Diego's rainfall in 2008-09 (July 1 to June 30) will probably be either below normal or only slightly above normal. It's unlikely there will be a repeat of the 22.49 inches recorded in 2004-05.
Keep the experts' opinions (below) in mind before submitting your entries in Weather Watch's annual Precipitation Prediction Contest. But remember: Many “experts” thought the Padres would finish first this year.
During an El Niño year, waters in the central Pacific are abnormally warm. The storm track often shifts south, and Southern California usually gets an abundance of powerful, wet storms. During a La Niña, those same waters are much cooler than normal, and storms tend to avoid us.
Late in the spring, sea-surface temperatures along the equator were rising, and an El Niño appeared to be brewing. But readings in late August showed the central Pacific had cooled and the trend had stopped. Forecasters now expect neutral conditions for the fall and winter.
When the Pacific is stuck in neutral, long-range forecasters have a much harder time figuring out what will happen. But we always try to pull numbers out of those experts anyway, because if they don't know, who does?
Dan Cayan, director of the Climate Research Division of the Scripps Institution of Oceanography in La Jolla, refuses to go out on a limb.
“I don't think I want to be very precise about this, because that would suggest a confidence I don't have,” he said. “Neutral years have gone in either direction (wet or dry). I'd have to go toward the middle – between 8 and 13 or 14 inches.”
William Patzert, a research oceanographer and long-range forecaster at NASA's Jet Propulsion Laboratory in Pasadena, is less hesitant. He believes a multiyear pattern known as the Pacific decadal oscillation, which suppresses storms in our area during its negative phase, will be the dominant player this winter. He predicts 6.26 inches for San Diego – the same number he predicted last year, when the city got 7.25 inches.
“The offshore high-pressure system will dominate the storm tracks and drive most storms to the north of San Diego,” Patzert said. “As always, a cutoff low or two is possible, but that will not be the norm.”
The Climate Prediction Center in Camp Springs, Md., is officially predicting an equal chance of normal, above-normal or below-normal precipitation for our area. Lead forecaster Mike Halpert said there is still a slight chance conditions could change in the Pacific in time to affect our winter.
“I'd say there's about a 5 percent probability of an El Niño, 85 percent for neutral, and about a 10 percent for La Niña,” Halpert said.
Most computer forecast models point toward the evolution of cooler-than-normal waters in the Pacific, but not cool enough to be a full-fledged La Niña, he said. He's predicting 8.75 inches.
Edward Aguado, a climatologist and professor of geography at San Diego State University, is also going low: 7.5 inches. He said San Diego's 10.77-inch annual average is skewed by the occasional very wet year. Most years, he said, the total is well below 10 inches.
Ivory Small, science and operations officer at the National Weather Service's Rancho Bernardo office, is a bit more optimistic. He's predicting 11 inches.
“We've had a good run of dry years recently, so you'd think it would start to kind of even things out,” Small said.
Your turn
OK. That's what the experts think. Is it enough to cloud the issue?
Now it's your turn to say how much rain will fall at Lindbergh Field, San Diego's official weather station, in 2008-09. Send your guess to rob.krier@uniontrib.com. Or mail your entry to Robert Krier, Precipitation Prediction Contest, The San Diego Union-Tribune, P.O. Box 120191, San Diego, CA 92112-0191.
Entries must be received by Sept. 26. In the event of a tie, please also state the calendar day that you think will be the wettest.
The winner will be the person who comes closest to predicting the actual total, either over or under. To the champion meteorological prognosticator will go a rain gauge and Weather Watch's undying respect. That's something you just can't buy out on the street – unless you make the right offer.
Visit the Weather Watch blog at Weatherwatch.uniontrib.com.
