AlQa'dah 09, 1436, August 24, 2015, SPA -- The massive cloud of smoke began to lift over the wildfires in Washington state on Sunday. But as air quality improves, the fire's behavior could become more erratic and intense, fire officials said, according to AP. "It's like a flue opening in a fireplace," explained Suzanne Flory, spokeswoman for the U.S. Forest Service and the Rocky Mountain Incident Management Team. "Smoke serves as a cap on the fire." The Okanogan Complex of wildfires was measured at 374 square miles (969 square kilometers) Sunday morning, after growing more than 100 square miles (260 square kilometers) larger Saturday in what fire officials said was a relatively calm fire day. Sunday was expected to be a different story. Once the smoke lifts, humidity drops, heat rises and fires flare up. Flory said they would not know until Sunday night or early Monday how much the fire had grown on Sunday, but as of late afternoon, fire activity had been relatively quiet. Visibility and air quality improved Sunday. The complex of fires was estimated to be about 10 percent contained as of Sunday morning, according to fire spokesman Dan Omdal. Some of the land within the fire lines is still burning, but other sections have burned out. "We call it a wildfire, but much of the fire has been tamed," Omdal said. "We are making progress," The good news for Sunday is that less smoke means restrictions on air travel will be lifted and more fire tankers can drop water and chemical retardant, Flory said. Air quality, which has been dangerously bad, will also improve when the smoke cloud lifts, but firefighters won't be able to take a breather. Meanwhile, local officials have downgraded some evacuation notices, allowing some people to return to their homes. Thousands remain under evacuation notices. Sarah Miller, a spokeswoman with Okanogan County Emergency Management, says residents have been warned to stay ready to leave at any time and to not drive around looking at the fires. Steve Surgeon, a mechanic and scrap metal seller who lives on the outskirts of Okanogan, said he was just happy to be alive. He stayed in place as the fire raced over a ridge and barreled down toward his home, flames lapping just feet from his back porch. "I'm alive," he said with a sigh Sunday. "I shouldn't be, but I am and that's what matters." Heaps of twisted and charred metal litter his land where the fire burned through. Surgeon estimates he lost more than $100,000 worth of property, including his shop, his motorcycle, several cars, a travel trailer and all of his tools. Three firefighters injured Wednesday in a fire near Twisp, Washington, are recuperating at home after being released from the hospital, according to the Washington Department of Natural Resources. A fourth injured firefighter remains in critical condition at Harborview Medical Center in Seattle, a hospital spokeswoman said Sunday. Three other firefighters were killed in the fire. Meanwhile, a new firefighting mobilization center is being set up at Fairchild Air Force Base near Spokane to help fight wildfires in Washington state. The base will be the staging area for 20 large fire engines and 10 water takers and will be run by a team from San Diego, California. The new firefighting resources come one day after the Obama administration approved Washington Gov. Jay Inslee's request for a federal emergency declaration to help firefighting efforts in the eastern part of the state. Sixteen large wildfires are burning across central and eastern Washington state, covering more than 920 square miles (2,383 square kilometers). More than 200 homes have been destroyed and more than 12,000 homes and thousands of other structures remain threatened. More than 1,000 people were fighting just the Okanogan Complex of fires on Sunday.