The recent cold snap may have damaged wheat on half the total acreage in Washington's Whitman and Garfield counties and about 40 percent of Idaho County across the border, extension agents warn.

And even worse news is the arctic front arriving late this week could cause even more devastation.The extent of the damage in the affected areas is not yet known. A clearer picture will be available in February or March.

One reason for the apprehension is that forecasts include high winds, which can blow away the snow blanket that insulates young plants.

Wheat begins to die without snow cover when the temperature falls to 10 degrees below zero. A blanket of snow can help keep the plant 20 degrees warmer than the ambient temperature.

Whitman County extension agent John Burns said about 50 percent of the county's 400,000 acres under wheat was without snow cover. Whitman is the largest wheat-producing county in the country.

Burns said about 15 percent of the crop in the area is on hilltops and does not have a good chance, even during milder winters. "You've kinda got to figure we've lost those," he said.

The hilltop wheat normally holds smaller yields, but Burns is unsure how badly frozen the remaining 35 percent of affected acreage is.

The temperature dropped about 30 degrees in a 12- to 24-hour period. This did not give enough time to the plants to "shut down" gradually.

Barley also is planted in the county, but it is a less hardy crop and if any was exposed it should be considered lost. Burns said only about 20,000 acres are planted with winter barley in the county.

At least half of Garfield County's wheat crop was hurt, said extension agent David Bragg. It normally produces on about 150,000 acres.

"I am concerned because there was very little snow cover at the beginning of the cold," Bragg said. "I suspect there is significant damage to wheat in parts of the county."

Ben Barstow, extension agent for Idaho and Lewis counties in Idaho, said up to 40 percent of the Idaho County crop may have been damaged.

"From what I have seen, the Greencreek area was the worst. That's the heart of wheat production in Idaho County," Barstow said. Wheat planted around Cottonwood also was hit, although the effect in nearby Grangeville may have been lighter.

"I'd say Lewis County looks pretty good. I would guess that probably 10 to 20 percent of acreage will have some damage," he said.

Extension agents in Idaho's Nez Perce and Latah counties were not available for comment Thursday, but those large wheat-growing counties may have fared better.

If a large amount of wheat is damaged by cold, farmers have the option of replanting in spring. But this will give much lower yields than the winter wheat.