Cold Snap Puts Growers on Notice : Weather: Unlike conditions during the devastating freeze last December, the recent episodes have been brief. Still, the wind machines are ready in some groves.

Farmers in Ventura County’s inland valleys were poised to activate their wind machines for the fifth night in a row Monday to protect their crops and orchards against the cold snap that began Thanksgiving Day.

But, unlike conditions during the devastating freeze last December, recent subfreezing episodes have lasted only a few hours.

And in place of the cold and still air that shrouded the groves last year, a warm air layer now hovers above the trees, allowing the wind machines to draw the warmth down into the groves.

No damage has been reported from the cold snap, which was expected to abate by tonight or Wednesday. Instead, the spell has probably helped the county’s crops, ranchers and agriculture officials said.

“The cold slows down the growth on the trees and hardens them to the cold nights we can expect in the next few weeks,” said Richard Pidduck, whose 77-acre ranch in the canyon along California 150 north of Santa Paula lost 95% of its citrus and avocado crop in last year’s freeze. Pidduck said temperatures in some of his orchards dipped to 27 degrees over the last few nights.

“But it was only for two to three hours,” he said, compared to the extended nightly freezes over four days last December. “The duration of the cold is just as important as the degree,” he said.

The weather was expected to stay cold Monday night and possibly through tonight in the county’s inland agricultural valleys, with lows dipping into the upper 20s, said National Weather Service Meteorologist Terry Schaeffer.

City areas, warmed by lights and heat from the roads, were expected to stay above freezing at 35 to 40 degrees both nights.

By Wednesday, a warming trend will raise nighttime temperatures to the low 30s and 40s throughout the county, Schaeffer said. By midweek, daytime temperatures should be in the upper 60s along the coast and into the mid-70s inland.

“This is just a normal garden-variety cold snap, nothing real cold compared to last year,” Schaeffer said. He said temperatures were five to six degrees below normal for this time of year.

No frost was visible on the fruit or ground because the air has been unusually dry, in the 10% to 20% relative humidity range, he said. The dry east winds of the last week that left the air crackling with electricity were expected to subside, allowing ocean breezes to blow in more moisture.

Last year’s four-day deep freeze that began Dec. 21 cost Ventura County growers $128 million in ruined crops. The county’s $853-million agriculture industry is not expected to fully rebound until 1993, when the last of the damaged avocado trees should begin producing normally again, authorities said.

Wind machines and grove heaters did little when temperatures dropped as low as 15 degrees for hours at a time in some county cold pockets last year. In other areas, farmers said, the machines, combined with other techniques used to protect orchards, may have saved at least portions of their crops.

The chilly Thanksgiving holiday weather this year found growers prepared, with wind machines and smudge pots already serviced to heat groves if necessary, growers said.

“We’ve been getting our machines ready for a month or so,” said Alfonso Guilin, executive vice president at Limoneira Co. in Santa Paula, the county’s largest citrus ranch. He said the temperatures had been cold enough to put the wind machines into action, but not cold enough to cause any problems.

Tony Thacher, manager of Friend’s Ranches Inc. in Ojai, said temperatures at his ranch have stayed above 30 degrees. He hasn’t needed the machines yet, but he and his crew were ready and waiting.

“After last year, I think everybody was ready to go,” he said. Friend’s Ranches lost about $300,000 worth of Valencia and navel oranges last year, he said. So far, the weather hasn’t been cold enough for him to worry.

“This was nothing,” he said. “But it’s still early. Things don’t start to get interesting until about the 15th of December.”