BRRRRRR TEMPERATURES TUMBLE, THREATENING FRAGILE CROPS AND BREAKING RECORDS.

Byline: ERIC LEACH Staff Writer

Los Angeles' balmy winter turned bitter cold Friday, with weekend temperatures forecast that could break 50-year-old records, endanger the homeless and cause $1 billion damage to the citrus industry.

Students shivered in bulky sweaters, transit riders donned scarves and parkas, and skiers and snowboarders headed for the mountains while growers in Ventura County fired up wind machines to protect their fragile crops.

Worried about the cold snap being felt throughout California, Gov. Arnold Schwarzenegger proclaimed a state of emergency and took steps to protect senior citizens and the disabled by activating warming centers at 11 National Guard armories statewide.

``Because of the extreme cold, I have directed state government to spring into action to protect our most vulnerable communities,'' said Schwarzenegger, who made financial disaster assistance available if needed and asked the California Highway Patrol to expand efforts to ensure motorists' safety.

The cold front that originated in Alaska could create ``extreme peril'' for residents, particularly the homeless, prompting the Los Angeles Homeless Services Authority to open its emergency shelters.

``We estimate that there are 90,000 homeless people on any given night in Los Angeles County,'' said Natalie Komuro, the authority's director of policy and planning. ``Many people are able to find a place to stay, but there are likely to be thousands in need of shelter.''

Temperatures could hit the 20s and low 30s in the San Fernando Valley and surrounding areas and drop into the low teens in the Antelope Valley, with snow levels dropping to 1,500 feet. That stands in stark contrast with the 80-degree temperatures recorded throughout Southern California earlier this week.

In Ventura County and throughout the San Joaquin Valley, growers stripped oranges, lemons and avocados from the trees, hoping to protect them from the frost.

The cold snap is not expected to be as extensive as the system that moved through in 1998, devastating the state's citrus industry.

``These are the coldest temperatures we have experienced since 1998, but in 1998 we had six nights in a row,'' said Bob Blakely, director of grower services for California Citrus Mutual. ``We have about $1 billion in fruit on the trees at risk.''

Joel Nelsen, president of the Citrus Mutual, said the industry took two years to recover from a weeklong freeze in 1990.

``The citrus season usually lasts until May, but a big cold snap can cut that down to ending it in 30 days,'' he said.

After the cold front passes, it will take several days to determine the damage but it shouldn't affect supplies of citrus fruit in the stores immediately because growers harvested crops Thursday and Friday before the coldest weather arrived.

``We have good inventory in the packinghouses,'' Blakely said. ``We're doing everything we can to be prepared. The balance is up to Mother Nature.''

David Buettner, Ventura County's deputy agricultural commissioner, said serious damage to crops usually starts occurring when temperatures fall below 28 degrees for more than four hours.

In Ventura County, a freeze could damage citrus, avocados and strawberries -- the county's biggest crops.

Meanwhile, Bill Hoffer, a spokesman for the National Weather Service in Oxnard, said snow levels could fall to 1,500 feet in the L.A. area.

``That's right down there on the floor of the deserts,'' he said.

The National Weather Service issued an advisory saying that while snow in the foothills and the Antelope Valley is expected to be minimal, the mountains could get a few inches, which could affect Interstate 5 from the Grapevine to Santa Clarita and Interstate 14 through Soledad Canyon.

The Associated Press contributed to this report.

eric.leach(at)dailynews.com

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CAPTION(S):

2 photos, box

Photo:

(1 -- color) A strawberry picker passes a smudge pot placed to combat the cold weather Friday in the fields in Oxnard.

Michael Owen Baker/Staff Photographer

(2) Bundled up from the cold Friday, riders wait at a bus stop on Lancaster Boulevard.

Jeff Goldwater/Staff Photographer

Box:

Winter chill

SOURCE: National Weather Service

Gregg Miller/Staff Artist