Evacuation orders in effect in Oregon, Washington

PORTLAND, Ore. -- A 87,000-acre wildfire burned along a milelong front Sunday, threatening about 60 homes, and the number of firefighters assigned to the blaze nearly doubled.

A voluntary evacuation order remained in effect for the threatened homes near Summer Lake, and several homes in the Silver Lake area also were in danger, said David Widmark, a spokesman at the Northwest Interagency Coordination Center.

Thunderstorms were forecast in the area of south-central Oregon with a likelihood of lightning but no rain, said meteorologist Paul Werth at interagency center.

Any new fires started by lightning could draw crews off the state's major blazes, Widmark said.

"What happens with the weather will tell us what the rest of the week will look like for fire behavior," Widmark said.

Officials dispatched an additional 800 firefighters to the blaze Sunday, bringing the total force to about 2,000 people, and National Guard troops are expected to arrive Monday.

The blaze was about 15 percent contained Sunday, Widmark said.

In addition to stiff wind and high temperatures, firefighters have faced a threat of electrical arcs as dense smoke creates short circuits between the ground and Bonneville Power Administration power lines in the area.

Blue bolts of electricity from the power lines already have killed several cows and firefighters won't go near the lines.

Two fires joined on Saturday to form the huge blaze on rolling hills between Summer Lake and Silver Lake, producing one leading edge about a mile long.

Elsewhere, a wildfire near the north shore of Lake Chelan in north-central Washington had burned about 17,000 acres, little changed from Saturday, officials said. It was about 10 percent contained.