LA NINA MAY RETURN FOR DRY REIGN.

Byline: David R. Baker Staff Writer

Southern California could face another dry winter and a longer fire season courtesy of La Nina, scientists warned Thursday.

The same weather phenomenon that cut the area's average rainfall in half last winter could return in the next few months, possibly extending the season of fire danger already expected to be severe.

``La Nina's in hibernation for the summer, with a high potential for coming back this fall,'' said Bill Patzert, who studies the phenomenon and its twin, El Nino, for Pasadena's Jet Propulsion Laboratory. ``For us, that means dry weather.''

Predictions of La Nina's rebirth are still preliminary, researchers say, and might not pan out.

But with long-range, computerized forecasts suggesting a dry winter ahead, Los Angeles-area fire officials say they are taking the threat seriously. The hillsides are covered with thick brush that grew during the lush El Nino spring of 1998 and is now bone dry.

``The lack of moisture in the ground and in the plants, combined with the summer 1999 heat - all that's going to be compounded by the upcoming La Nina winter,'' said Capt. Paul Quagliata, commander of the Los Angeles Fire Department's brush clearance unit.

He urged homeowners to cut back vegetation growing within 200 feet of their homes. ``The situation is really deteriorating,'' Quagliata said. ``It's very, very important that people be aware of this, deal with it and not become complacent and let it slide.''

La Nina and El Nino are both part of the same climate cycle in the Pacific, an unending dance between ocean and atmosphere.

El Nino forms when unusually warm water pools in the eastern equatorial Pacific, triggering weather changes around much of the world. The phenomenon typically drenches Los Angeles with rain while other areas suffer drought.

During La Nina, the eastern Pacific turns colder than normal, usually cutting the amount of rain that reaches southern California.

Traces of last winter's La Nina still linger in the Pacific, and despite this week's heat wave, water temperatures along the California coast remain several degrees below normal.

While most computerized models suggest the water will cool off again this fall, Nicholas Graham at the Scripps Institution of Oceanography said it isn't clear how strong the phenomenon would be.

He also said it was unknown exactly what effect a resurgent La Nina would have on local rainfall, although the area probably would get less precipitation than normal.