Some say the recent chill in the Valley is disturbingly similar to last season's devastating freeze.
By Dennis Pollock / The Fresno Bee
12/01/07 21:48:53

Temperatures dipped into the 20s in the Valley's citrus growing regions late Friday and early Saturday, prompting growers for the first time this season to turn on wind machines that protect groves by pulling warmer air from above.

"I don't think there was any damage, but it's way too early to tell," said Nick Hill, whose groves endured temperatures of around 29 degrees for nearly five hours.

For Hill, the conditions that brought the dive in temperatures were all too reminiscent of what growers faced earlier this year when a devastating freeze resulted in the loss of hundreds of millions of dollars of mostly navel oranges.

"It was the same pattern ... cold and clear nights," seen last season, said Hill, whose groves are in the Orange Cove, Reedley and Dinuba areas.

But National Weather Service meteorologist Gary Sanger said the current weather conditions differ from last season's stretch of freezing nights because there is more moisture in the air. He also said light winds were keeping temperatures slightly higher.

Still, the weather service issued a frost advisory for the Valley from Merced and Mariposa counties south to Kern County from midnight Saturday until 9 a.m. today. Overnight lows were expected to be between 28 and 32 in the central San Joaquin Valley, the weather service said.

Temperatures Saturday night and into this morning were expected to be much the same as Friday night's plunge, said Tom Dunklee, an atmospheric scientist with Weather Watch, which monitors weather in the citrus-growing region.

A very dry atmosphere, coupled with a lack of soil moisture, is contributing to freezing conditions, Dunklee said.

Hill said he would like see a storm move through the region to bring moisture and move the air to break up the conditions that make for freezing weather.

"There are no active weather systems to move the air into and out of the Valley," Hill said.

Sanger said there is a slight chance of rain for Thursday and Friday, "but right now, it doesn't look all that impressive yet."

Rainfall is far below normal, with just 0.39 of an inch so far this season, compared to the 2 inches normally expected. After an unusually warm fall, the current colder temperatures are about normal, the weather service reported.

Dunklee's list of citrus areas included Orosi with a low of 25 degrees, parts of Porterville and Ivanhoe at 26 and Lindsay at 27.

Rod Radtke, with Harris River Ranch Farms, said the cold front moved in about 24 hours earlier than expected. "It jumped the gun," he said.

Radtke said some growers were running wind machines as early as Nov. 9 last year. He said early use of the machines has been more common in recent years.
Reporter Anne Dudley Ellis contributed to the report. The reporter can be reached at dpollock@fresnobee.com or (559) 441-6364.

Source: http://www.fresnobee.com/263/story/238167.html