A change in the weather — with winds easing and humidity rising — has helped firefighters battling massive blazes in Oregon that have taken a deadly toll from one end of the state to the other.

Oregon's Governor Kate Brown said Friday that dozens of people were still missing and tens of thousands had been forced to flee their homes. The state's emergency management director, Andrew Phelps, said officials are "preparing for a mass fatality event" and thousands of structures have been destroyed.

Oregon officials haven't released an exact death count but at least eight fatalities have been reported. Marion County Sheriff Joe Kast said Friday evening that searchers had found two victims of the Beachie Creek fire near Salem. A one-year-old boy was killed in wildfires in Washington.

Hundreds of firefighters were battling two large blazes that threatened to merge near the most populated part of Oregon, including the suburbs of Portland.

Brown said more than 40,000 Oregonians have been evacuated and about 500,000 are in different levels of evacuation zones, either having been told to leave or to prepare to do so. She dialed back a statement late Thursday by the state Office of Emergency Management that said a half-million people had been ordered to evacuate statewide.

Scores of people were missing in Jackson County in the southern area of the state and in Marion County east of Salem, the state capital, Brown told a news conference. Authorities also announced that a man had been arrested on two counts of arson in connection with a fire in southern Oregon.

Improved weather helped efforts on the ground after days of high winds, heat and low humidity. "The wind laid down quite a bit for us yesterday," said Stefan Myers of the state's fire information team.

Almost 500 personnel were working on the fires near Portland, which were just a few kilometers apart, with rugged terrain between them that limits boots-on-the-ground efforts to control the flames, Myers said. If the fires merge, they could generate enough heat to send embers thousands of feet into the air, potentially igniting other areas.

Authorities say more than 3,880 square kilometers have burned in Oregon during recent days, nearly double the amount in a typical year and an area larger than Rhode Island.

Washington Governor Jay Inslee noted that the amount of land burned in just the past five days amounted to the state's second-worst fire season, after 2015. He called the blazes "climate fires" rather than wildfires.

"This is not an act of God," Inslee said. "This has happened because we have changed the climate."

Jackson County Sheriff Nathan Sickler said a 41-year-old man was jailed on two charges of arson for a fire that started Tuesday in the Phoenix area in southern Oregon. The fire burned hundreds of homes and also had an ignition point in Ashland near a spot where a man was found dead. Authorities said the man denied starting the fire.

Sickler said authorities were working to locate missing people.

"I think we're somewhere in the neighborhood of, you know, around 50 individuals that, you know, we're trying to locate maybe a little less," he said. "It's going to be a process for sure."

Evacuation centers were open across Oregon.