In Oregon, a New Climate Menace: Fires Raging Where They Don’t Usually Burn
The blazes that raced across western Oregon this week could be the most unexpected element in a fire season that’s full of surprises: Not just more wildfires, but wildfires in places that don’t usually burn.
The forests between Eugene and Portland haven’t experienced fires this severe in decades, experts say. What’s different this time is that exceptionally dry conditions, combined with unusually strong and hot east winds, have caused wildfires to spiral out of control, threatening neighborhoods that didn’t seem vulnerable until now.
“We’re seeing fires in places that we don’t normally see fires,” said Crystal A. Kolden, a professor of fire science at the University of California, Merced. “Normally it’s far too wet to burn.”
The fires in Oregon, which have led to the evacuation of hundreds of thousands of people and are approaching the Portland suburbs, stand out from what has already been an extraordinary fire season in the West, where global warming, land-use changes and fire management practices have combined to create a hellish mix of smoldering forests, charred homes and choking air.
Before this week, Oregon was grappling with a much more contained problem, a series of smaller fires on both sides of the Cascade Range, which divides the state between east and west.
The Medford Estates neighborhood of Medford Oregon lay in ruins on Thursday.
Fires are common in the east, which is normally dry, according to Philip Mote, a climate scientist at Oregon State University. In some areas of eastern Oregon the “return period,” or length of time between major fires, is as little as 20 years, he said.
But the western slope of the Cascades, which catches most of the moisture that blows in from the Pacific Ocean, is normally wetter. “Out here, the return period can be hundreds of years,” he said.
That protective moisture has faded, in large part because climate change has altered precipitation and temperature patterns.
Tim Brown, director of the Western Regional Climate Center at the Desert Research Institute in Reno, Nev., said the extreme warmth had caused vegetation to become exceptionally dry and to burn more readily. Temperature, humidity, wind and solar radiation combine to dry out brush and are the key elements for fire. “We call it evaporative demand,” he said. And in recent weeks, he added, “the west Cascades have been really dry from the evaporative demand.”
Those dry conditions were most likely exacerbated by climate change, according to Meg Krawchuk, a professor at Oregon State’s College of Forestry. And they had the effect of “teeing up the landscape” for a wildfire, she said.
The critical moment came Monday and Tuesday, when a windstorm carried hot air from the high desert in the eastern part of Oregon over the mountains, rapidly spreading the fires in the more populated western part of the state, according to Josh Clark, fire meteorologist at the Washington State Department of Natural Resources.
Those winds were the strongest the state has seen in at least 30 years, Mr. Clark said. And when they crossed the mountains, the winds raced down through river canyons, which compressed the air, warming it further and pushing it westward like a bellows.
As those fires raced west, they met unusually dry conditions, said Dr. Kolden, which in turn allowed the fires that were already burning to spread rapidly. “The fire’s able to move very quickly and just explode down these canyons,” she said.
A blanket of smoke above Salem Oregon.
The fires now threatening Oregon’s cities and towns could be worse than anything in that part of the state in decades, said Cassandra Moseley, chief research officer at the University of Oregon and a professor at its Institute for a Sustainable Environment. Tens of thousands of Oregonians have already been evacuated, and about 500,000 are in areas that may be ordered to flee as the fires grow. Towns including Talent and Phoenix have already been largely obliterated, and new deaths were reported on Friday. Three new deaths in Oregon were reported on Friday, as dozens of people remain missing.
The Jackson County Sheriff’s Office said the Almeda Fire started around 11 a.m. on Tuesday in Ashland, Ore., and then began spreading north along Interstate 5. Around 5 p.m., residents reported that a man had started a fire in Phoenix, a town of about 4,500 people just north of Ashland that was under orders to evacuate, authorities said.
The Almeda fire.
The Sheriff’s Office said police officers discovered Michael Jarrod Bakkela at the scene, denying that he started the large fire nearby. Police arrested him on a parole violation.
On Friday, the Jackson County district attorney charged him with arson, criminal mischief and reckless endangering.
Law-enforcement officials across the state said they had been swamped with calls about social-media misinformation and begged people to “STOP. SPREADING. RUMORS!” In the line of fire, the swirl of rumors actually helped goad some people into defying evacuation orders so they could stay and guard their homes.
The Tillamook Burn, a series of fires that began in 1933 and destroyed hundreds of thousands of acres, was probably as bad as this week’s fires, Dr. Moseley said. It’s hard to know for sure, she said, because “no one’s alive to tell the tale.”
And what’s different this time, Dr. Moseley said, is that far fewer people lived in those areas 90 years ago. “Tillamook didn’t have people in it,” she said. By comparison, this week’s fires seem likely to cause large numbers of casualties.
