DEARTH OF RAIN HIKES FIRE RISK.

Byline: Robert Monroe Staff Writer

As the temperature creeps toward the 100-degree mark in the San Fernando Valley area, the lack of rain in the past 12 months - the fourth-lowest rainfall total in 50 years - has heightened the danger of brush fire, officials said Tuesday.

The Valley got 9.79 inches of rain in the year ending today. The National Weather Service measures rainfall from July 1 to June 30, called a water year.

The 1998-99 total is 5 inches lower than normal, according to the Los Angeles County Department of Public Works.

This year's figure is also swamped by the 40.19 inches dumped on the Valley by El Nino in 1997-98, according to Western Regional Climate Center records measured at Pierce College.

The flip-side phenomenon known as La Nina is the source of the drier season and fire officials said combinations like this have set the stage in the past for catastrophic fires like the 1993 Topanga Canyon Fire, which destroyed more than 350 homes. Wet then dry weather leaves behind quick-sprouting short grasses and shrubs that die quickly without water and then become excellent fire fodder.

``What we call the flash fuels have grown more than in many, many decades,'' said Los Angeles Fire Department Battalion Chief Terry Manning, who was a strike team leader in the Topanga blaze.

Kern County Fire Department Inspector Joe McElroy blamed the triple-digit temperatures and the lack of rainfall for a fire that burned hundreds of acres Tuesday evening along the Grapevine, the first major fire in Kern County this fire season.

The fire started at 11:45 a.m. along I-5 five miles south of Lebec, when a driver pulled his overheating car into the grass along the freeway and the engine caught the grass on fire.

Meteorologists said this year's dryness does not constitute a drought, noting that snowpack levels in the Sierra Nevada, the source of much of Southern California's water, are greater than normal by about 10 percent this year. The National Weather Service said below-normal rainfall must be present for several years to precipitate a drought.

``It's way too early to call it a trend,'' said Bruce Rockwell of the National Weather Service.

La Nina originates in cooler-than-average ocean waters off the coast of South America. The phenomenon, still not completely understood by climatologists, forces the jet stream further north. In the United States, that displacement results in higher-than-average rainfall in the Pacific Northwest, said Greg McCurdy, an assistant climatologist at the Western Regional Climate Center.

``For such an intense La Nina to follow an intense El Nino is very unusual,'' McCurdy said.

In the 50 years that rainfall has been measured at Pierce College, the driest water year on record was 1960-61, when only 6.01 inches fell.

CAPTION(S):

2 charts

Chart: (1) Dry times

(2) Dry seasons