ANOTHER DROUGHT? MAJOR L.A. WATER SOURCE AT 25% NORMAL.

Byline: Jesse Hiestand Staff Writer

Halfway through the seventh driest rainy season since 1877, Los Angeles now faces another problem: The Sierra snowpack is at just 25 percent of normal, officials said Monday.

No drought is imminent because Los Angeles' reservoirs are brimming from previous wet winters, but officials said they worry about next year if dry conditions persist in the Sierras, the source of 40 percent of the region's drinking water. Less than half an inch of rain has fallen so far in Los Angeles, as compared with a normal 4.7 inches.

``We'll be entering the new year with all our fingers and toes crossed that we get some good snowfall and rain,'' said Jeff Cohen, spokesman for the California Department of Water Resources.

The region is struggling through the seventh driest rainy season since at least 1877, when records first were kept. The last drought lasted five years, from 1987 to 1992, and the last driest winter-to-date was in 1990 when just 0.21 inches had fallen.

The Sierras has a snowpack equivalent of just 3 inches of water runoff, compared with a foot in a normal year for the same period.

Last year, La Nina left Southern California parched, but sent the storm-laden jet stream into the Sierras, assuring enough snow. This year's La Nina seems to be different; forecasters are drawing comparisons to another notorious La Nina year - 1975-76 - when the northern Sierra range ended up with just 57 percent of its normal water.

``That led into two of the driest back-to-back years in the state this century,'' said state climatologist Bill Mork of the water resources department.

With wildfires burning in Arcadia and recently in Glendale, the lack of rain is nowhere more visible in Southern California.

Just 0.44 inches of rain has fallen since July 1 at the University of Southern California, as compared with 4.7 inches by this time in a regular year, according to the National Weather Service.

Even last year, amid parched conditions wrought by La Nina, Los Angeles had already received 1.8 inches of rain, said NWS meteorologist Rich Thompson.

``It's quite amazing how dry we've been so far this water year,'' Thompson said.

The weekend may usher in a long-overdue shift in the weather, but forecasters are hesitant to make any firm predictions on rain.

``We're expecting the overall pattern to change over the weekend and into next week,'' said Thompson. ``Conditions will be a bit more favorable to getting some rain to develop here.''

Just about any storm would be welcome on the eastern slope of the Sierras, where the Los Angeles Department of Water and Power is ready to seed the clouds to wring out any extra moisture.

The lack of any workable storms kept cloud-seeding planes grounded throughout December, after just two flights the month before, said Simon Hsu, a DWP runoff forecaster.

``So far the snowpack's not looking too good,'' Hsu said, noting that Mammoth Pass has just 3.24 inches worth of water now, while it should be at about 18 inches.

Hsu and others remain hopeful that the final three months in the rainy season, beginning Jan. 1, will make up the difference and feed the city-owned Los Angeles Aqueduct, which supplies 70 percent of the fresh water.

If not, they may be forced to rely more heavily on the Metropolitan Water District, which already supplies 15 percent of the city's water through the California Aqueduct and Colorado River. The remaining 15 percent comes from groundwater.

Weather officials are further banking on the erratic nature of the La Nina pattern, which often steers the jet stream and its storm track to the north of California but does not always result in a dry year for the snowpack.

A DWP study of seven La Ninas since 1950 found that the eastern Sierra runoff varied from 58 percent of normal to, on one occasion, 130 percent of normal, Hsu said. That resulted in an average deficit of 8 percent below normal.

In the near Eterm, the MWD, the main water importer and wholesaler to the urban Southern California region, does not foresee any serious problems with its supply, especially since the Colorado River is at adequate levels.

``At this point we are comfortable with the water supplies,'' said MWD spokesman Rob Hallwachs.

And for now, state officials agree, saying that their largest reservoirs, which store 85 percent of the state's water, were 20 percent above normal on Oct. 1 and remain 15 percent above normal, Cohen said.