THE celebrity TV weatherman was pretty much invented in Los Angeles. They have names like Dallas Raines and Johnny Mountain, and before them, the avuncular man in the bow tie known to millions simply as Dr. George.
Steve Martin mocked this culture in his movie "L.A. Story," in which he plays a weatherman who tapes his forecasts in advance because, well, L.A. has no weather.
But although the TV news provides the overnight lows and five-day forecasts, the job of understanding the weather and making the long-term predictions falls to the meteorologists and climatologists who toil behind the scenes.
Many work for the federal government and universities. They are generally a conservative bunch, quick with the caveat and the nuance -- knowing their forecasts can have huge and costly implications, including how farmers plant their crops and how government agencies calibrate water supplies.
Then there is Bill Patzert.
Over the last two decades, the climatologist at NASA's Jet Propulsion Laboratory in La Canada Flintridge has emerged as perhaps the leading expert on weather in Southern California. He was one of the scientists ahead of the curve on predicting the effects of a huge El Nino in 1998 and ever since has tilted with the windmills of meteorology convention.
Shortly after NASA ordered its scientists in 2004 not to comment on the global warming catastrophe movie "The Day After Tomorrow," Patzert appeared on the CBS Evening News in a Hawaiian shirt.
"Anyone who thinks the human race does not have a powerful impact on the environment and climate," Patzert said, "definitely has their head in the sand."
To some meteorologists, Patzert has become just like one of those TV weathermen -- quick with the flashy quote.
But the 65-year-old surfer has also gained a loyal following from those who say his forecasts for Southern California are simply the most accurate. Over the last five years, the National Oceanic and Atmospheric Administration in Washington predicted three times that increasing sea surface temperatures in the tropical Pacific -- the phenomenon known as El Nino -- would result in wetter-than-normal winters in Southern California. Each time Patzert disagreed.
Much to the dismay of federal scientists, he started talking about "fictional El Ninos," flaccid "El Wimpos" and disappointing "El No Shows."
In July, NOAA predicted another global El Nino, expected to affect Southern California and the Southern states. The 2006-07 season, it said, would be warm and rainier than average.
Patzert's forecast: Dry. Really dry. And he was willing to stake his reputation on it.
WHY are there such enormous disparities between forecasts?
One reason: When it comes to El Nino, NOAA tends to emphasize data from a network of buoys running across the equatorial Pacific from Asia to the Americas. They make measurements on the upper 500 meters in the ocean, where the major deviations in temperature take place. The weather consequences can be dramatic depending on the size of the temperature increase, the area of ocean involved and the duration of the phenomenon. For NOAA, an increase of about 1 degree Fahrenheit over three months in a defined area of the Pacific meets the threshold for El Nino.
Patzert, on the other hand, is an expert in analyzing satellite data.
The satellites measure the elevation of the sea surface as a result of the expansion of water as temperatures increase in the upper 500 meters. The satellites are not as hyperfocused on El Nino and look beyond to other climate patterns.
One of those patterns is the Pacific Decadal Oscillation, a slow-moving variation of temperatures between the western and eastern sections of the Pacific. In 1998, the western Pacific was becoming warmer than the eastern Pacific, leading Patzert to conclude that in the long term, an "El Nino-repellent" pattern was forming that would favor drought in Southern California for many years.
The technologies each have strengths that complement each other, as well as blind spots, but perhaps the biggest wild card is how human beings interpret the data.
"There's a competitive sense over who owns the big phenomenon, and who understands it," said James Baker, who headed NOAA from 1993 to 2001.
Patzert has made Southern California his beat. On Wednesday, he and two other researchers released a NASA-JPL study showing that California's temperature rose nearly 2 degrees Fahrenheit in the last 50 years, largely because of urban growth.
His expertise in the region has won Patzert some loyal disciples, including Robert Krier, the San Diego Union-Tribune's Weather Watch columnist.
"Patzert has been reliably closer to the actual total at the end of the season than [NOAA], our local National Weather Service guys, a local meteorology professor and the Scripps guy," Krier said. "He was one of the few to go below normal on the rainfall prediction for this year. The others were convinced El Nino would dominate."