SEATTLE (Reuters) - Dry conditions and wind plagued ground crews fighting the largest wildfire in Washington state history on Tuesday, as flames scorched more than 1.6 million acres (648,000 hectares) across the bone-dry western United States.
The National Weather Service issued a fire weather warning through Tuesday evening for central and northeast Washington state, while unhealthy air quality alerts have also been made for parts of Oregon, Idaho and Montana due to wildfire smoke.
Nearly two dozen fires in Washington and Oregon alone have scorched more than 1 million acres (405,000 hectares), according to the National Interagency Fire Center in Boise, Idaho.
In north-central Washington, a cluster of deadly fires dubbed the Okanogan Complex has burned more than 258,339 acres (104,546 hectares), overtaking last year's Carlton Complex fire as the state's largest on record. It was just 15 percent contained.
Firefighting conditions worsened as a slightly cooler layer of atmosphere which had effectively dampened the fire began lifting from the area on Tuesday afternoon, whisking away thick smoke that had grounded water-dropping aircraft but also kicking up wind and heat, information officer Peter Frenzen said.
Water-dropping helicopters and airplane tankers returned to the skies on Tuesday as visibility increased, Frenzen said.
Last week, three firefighters were killed and four were injured in an initial assault on part of the Okanogan Complex.
Smoke was also dispersing over a cluster of fires around Lake Chelan, some 50 miles (80 km) to the south, though smoke will likely return on Wednesday, officials assigned to the blaze said.
The fires have scorched 88,104 acres (35,654 hectares), and some 1,000 residents in the broader area of Chelan, a resort town at the base of the lake, were under evacuation orders. The fires were about 40 percent contained.
A 16-year-old inmate on a work gang assigned to the fire, who fled his unit over the weekend with a stolen handgun and later shot himself in the head during a brief standoff with deputies, is being treated at a Seattle hospital, officials said on Tuesday. His condition was not being made public.
This summer's blazes have stretched resources thin, prompting a rare enlistment of firefighting reinforcements from the U.S. military and foreign countries.
Dozens of fire managers and firefighters from Australia and New Zealand reported to the interagency fire center's Boise headquarters on Monday, preparing for deployment against the Washington wildfires, the U.S. Forest Service said.
About 200 U.S. Army soldiers from Joint Base Lewis-McChord near Tacoma have already joined the front lines in Washington, as have crews from Canada, the fire center said.
Firefighters are bringing in air monitors to eastern Oregon communities surrounded by wildfires and choked by thick smoke to determine just how dangerous the air has become, the Forest Service said.
In south central Oregon, residents were ordered to evacuate from the path of the Canyon Creek Complex, which is threatening as many as 130 homes and formed when three fires near the community of John Day merged, the Forest Service said.
(Reporting by Curtis Skinner in San Francisco and Eric M. Johnson in Seattle; Additional reporting by Courtney Sherwood in Portland, Oregon; Editing by Cynthia Osterman and Chris Reese)