(UPDATED COVERAGE, Nov. 26) California grower-shippers will continue uninterrupted shipping of navels and mandarins in the wake of the fall’s first arctic storm.

Temperatures were forecast to be 27 degrees or warmer in the citrus growing regions of the San Joaquin Valley the night of Nov. 25-26, according to California Citrus Mutual, Exeter. As the cold front moved out of California, temperatures were expected to continue to warm into the weekend.

Navels can experience internal freeze damage if temperatures drop to 27 degrees or lower for extended periods.

California citrus survives season’s first cold snap

The front’s coldest period was forecast for the night of Nov. 24-25, but clouds kept most readings above the danger level.

“There were isolated pockets of 27 degrees for short durations, but the vast majority of the valley's 200,000-plus acres were all at 30 degrees or better before dawn,” Joel Nelsen, president of Citrus Mutual, said early Thanksgiving Day morning.

The holiday’s coldest readings were recorded in Kern County at the southern end of the valley.

“We turned on the wind machines in just one grove,” said Neil Galone, vice president of sales for Booth Ranches LLC, Orange Cove, which has more than 6,000 acres of citrus in the valley. “We cut some Kern County navels in the middle of the night, and the pulp temperature was 42 degrees.”

Due to the season’s late start, about 95% of the estimated navel and mandarin crops is still on the trees. The cold front will actually improve the crops.

“The cold snap not only thickens the skin of the fruit, it will also give us the color we need to bring down the degreening time significantly,” Galone said. “It will help with color, flavor and shelf life, which has a long term benefit for our customers.”

In the Salinas Valley, frosts were reported but no significant damage.

West of Gonzales in the Santa Lucia foothills, lemon- and avocado-grower Old Oak Ranch battled a 27-degree frost Thanksgiving Day, said Kirk Williams, partner and manager.

"I had helicopters and wind machines going on it, pretty much everything," Williams said. "That boosted it to about 29."

Old Oak Ranch grows 850 acres of lemons and 150 acres of avocados.

The crops were free of damage, and the effort proved a useful test run for future winter weather, Williams said.

"We've got 55 wind machines and they're fully operational and up to snuff," he said. "It just gets the bugs out of everything early in the season. We're ready for more should we need it."

In Castroville, there were morning frosts on the holiday and the day after. But the effect was minor, said Art Barrientos, vice president of harvesting at Ocean Mist Farms.

"It was nothing significant," he said. "If we continue to experience these frost mornings, by sometime next week we might be looking at light to moderate damage."

"We're still finishing up broccoli and cauliflower the end of this week and early next week," he said Nov. 26. Artichoke production is ongoing.

On frost days, fields can't be accessed as early in the morning as usual.

"All it's doing is delaying the work day," Barrientos said. "There are no production issues with any of the commodities."

Staff writer Mike Hornick contributed to this report.