Updated

More rain was expected Friday and into the weekend, a welcome forecast for firefighters protecting multimillion-dollar telescopes at a southeastern Arizona observatory threatened by two wildfires (search).

Scattered showers were forecast for the mountains Friday, a day after light rain fell on rugged Mount Graham, helping to raise the humidity, said Brent Wachter, a National Weather Service (search) meteorologist.

The low humidity and high temperatures had been driving the wildfires threatening the $200 million Mount Graham International Observatory (search) and two communities of summer homes.

The higher humidity could slow the wildfire's growth, but it also created the potential for high winds that could spread the flames and lightning strikes that could spark more fires. The fires were both started by lightning.

Firefighters focused their efforts protecting the nearly 100 homes in Turkey Flat and Columbine on the flanks of the mountain. They also reinforced protection for the observatory.

Officials were confident Friday that 74 cabins in Turkey Flat could be saved. "It seems like we're going to be dodging that bullet," said Dean McAlister, fire management officer for the Coronado National Forest.

Officials said the fires, which have charred nearly 26,000 acres, had grown no closer to either community by midday Thursday.

One fire, estimated at 16,300 acres, was burning up a canyon and officials were worried it would reach the 74 cabins at Turkey Flat. The fire also was within a quarter-mile of the observatory.

Another fire, which had burned 9,400 acres, was about 11/2 to two miles from Columbine, a community of about 15 homes and cabins.

The fires were approaching the observatory from different directions, but officials were hopeful they could save the facility. It was nearly surrounded by defensive lines cut by bulldozers and reinforced with burned-out areas and a sprinkler system.

The blazes were considered 35 percent contained, according to authorities.

Fire managers said they were most concerned about firefighter safety as storms blew in with rain and erratic winds. Lightning and the possibility of flash floods in drainages and canyons were among the biggest risks.

"This mountain is a big lightning rod," said McAlister.

Elsewhere, officials planned to keep closed for a few more days the only direct highway linking Phoenix to Payson, a popular summer destination, because of erratic fire behavior on a 109,900-acre blaze in the Tonto National Forest in central Arizona.

The fire crossed State Route 87 on Wednesday night. The lightning-caused fire, which started June 24, was considered 25 percent contained by Thursday.

In central Washington state, one of two wildfires burning near Lake Chelan was declared fully contained Thursday evening.

The fire, about three miles east of the lake and the Columbia River, had burned about 4,205 acres, said Carson Berglund, fire information officer. A voluntary evacuation for about 45 homes was lifted Wednesday night.