How an Easterly Wind, Hotter Summers Could Fuel More Devastating Wildfire on Western Slopes of Cascades

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The wind howled out of the east, ripped over ridgelines, funneled through river valleys and battered mountain passes.

Near Snoqualmie Pass Monday and under blue skies, Garret and Kirsten Van Swearingen drove dirtbikes up a ridgeline overlooking Interstate 90, hoping for a view of the sunset.

Within a half-hour, the skies darkened as "hot winds full of smoke" began to gust near 30 mph, Garret said. From a vantage point that offered a clear view of Mount Rainier most summer days, the couple saw "a river of smoke" pouring through the pass. A haze-reddened sun hung overhead.

"Pretty darn apocalyptic," Garret said.

Since Monday, these winds have left in their wake cruel reminders that wildfire has a history of scorching the land not only east of the Cascade crest, but on the west side, too -- where scientists have recorded massive conflagrations that swept through the landscape.

More than 1.5 million acres have burned this past week in Washington and Oregon. The town of Malden in Whitman County was nearly destroyed by a blaze and a 1-year-old child was killed in a fire in Okanogan County. Oregon has fared far worse, with more than 40,000 people being told to evacuate. At least seven people have died and dozens remain missing in counties hard hit by fires. Hundreds of homes have been destroyed with some neighborhoods reduced to rubble.

Today, climate change has primed the region's landscapes for wildfire, pushing summer temperatures higher, drying vegetation and stretching out the fire season.

And scientists now are examining whether climate change could play a role in driving the wind events that history shows have wreaked destruction on the region's west side.

In Western Washington, cool onshore flow from the Pacific Ocean typically keeps summer skies blue as a robin's egg.

But on Monday, that wind pattern was thrust into reverse.

Californians know the phenomenon as the Santa Ana winds or Diablo winds. Here, we call them east wind events.

"These other places have sexy names," said Josh Clark, a fire meteorologist for the Washington Department of Natural Resources (DNR). "The east winds -- it doesn't get anybody's attention."

Until wind-whipped wildfires roar through.

Gusts out of the east Monday topped 55 mph in the Columbia River Gorge, clocked in at nearly 50 mph near White Pass and hit 26 mph in Seattle.

By Tuesday, the Cascade Mountains' west slope was parched. Relative humidity measures dropped as low as 6%.

"Six percent is like Joshua Tree -- desert," Clark said. "It doesn't get much lower. I guess on Mars."

Pockets of wildfire erupted on the westside, torching a Tacoma park, burning down homes elsewhere in Pierce County, forcing hundreds to evacuate and shrouding Seattle in thick, unhealthy smoke.

Fire driven by an east wind

Memories are short, particularly when something occurs on a cadence measured in lifetimes.

In early September 1902, a series of fires -- buoyed by an east wind -- sprang up in Southwest Washington.

Now known as the Yacolt Burn, one of these blazes roared down a hill and incinerated a picnicking family before they could reach a creek, according to the book "Burning an Empire," by Stewart Holbrook. Another blaze overtook a homestead, where a mother died with an infant in her arms. Another family could not manage to flee their yard before the flames hit.

At least 38 people died, Holbrook wrote. Researchers believe the Yacolt burned about a quarter million acres of land -- among the largest fires recorded in Washington.

Joshua Halofsky, a research scientist with the Washington DNR, said the Yacolt Burn bears remarkable resemblance to the events last week.

Massive fires across the western slopes of Washington and Oregon's Cascades -- such as the Yacolt and the Tillamook Burn, which began in the 1930s -- share a common recipe.

"You need the end of summer after a warm and dry period, an ignition source and those east winds," Halofsky said. "You need that rare alignment of all these key ingredients to get these large fires going."

Western Washington forests are among the most productive in the world.

"There's always enough fuel on the landscape" to burn, Halofsky said, adding that scientists believe large fires swept through dense Western Washington forests every hundred years or so. These fires are considered "stand-replacing" -- meaning entire swaths of the forest would be seared away and set to regrow.

One fire episode -- in 1701 -- burned between 3 and 10 million acres in Western Washington, Halofsky said, citing a forest service review.

But now people are priming the pump.



Humans -- who start most fires in Western Washington -- are flocking to wildland areas to live and to recreate, and that might create blazes.

"With more people, you have more ignition opportunities," Halofsky said. "Most of the fires we're seeing today -- were also sparked by humans, either directly, or with downed power lines."

Questions remain about the last ingredient for widespread and destructive fires -- the wind, which is notoriously finicky to pin down in climate models, said Crystal Raymond, a research scientist with the University of Washington's Climate Impact Group.

Along with Halofsky, Raymond is among a team of scientists trying to determine whether these east wind events are growing more or less frequent or intense.

"We have clear evidence climate change is setting the stage. The piece we don't have is whether climate change is affecting these east wind events that trigger" these large wildfires, Raymond said.

Clark, the DNR fire meteorologist, described the common perception of wildfire risk in this state as an eastern Washington problem as naive.

"I would argue the fire risk is greater over here because of the amount of people living in the wildland-urban interface and the potential risk should we get an east wind event," Clark said. "We're seeing that play out on the west slopes of Oregon right now."

High winds topple power lines

In Oregon, the fires this week burned across a wide expanse of the state, including the western flanks of the Cascades, the Coast Range and even into lowland valley areas in the Willamette Valley. These fires were driven by gusts of up to 50 mph, and this wind turned power lines -- long a fire problem in California -- into a big risk for starting fires in Oregon, as well as Washington.

The Beachie Creek fire, which flared in the Santiam Canyon west of Salem, and more than a dozen ignitions were started by downed power lines, feeding a fast-moving blaze that required harrowing evacuations of people living along a 40-mile stretch of highway. The numbers of structures lost -- and death toll -- in this fire has yet to be determined.

Fallen power lines also sparked smaller, more isolated fires such as the one that flared close by Patrick Snell's home in the farm country of Clackamas County south of Portland.

"All of a sudden you heard ka-boom, ka-boom, and one of the lines snapped," recalls Snell, who ran outside to find a tree had done the damage a short distance down the road where he lives.

Smoke billowed up from a fallen Portland General Electric line, which he said eventually ignited fires in several places.

Fire engine crews showed up. But Snell said their initial efforts to fight the blaze were hampered by the utility, which he said took at least 30 minutes to shut off the power. And those delays were costly, he said.

Flames eventually raced across a grass field, and then reached a lumber mill yard, burning outbuildings and torching log piles.

"They need to have some emergency type set up where they can have the power shut down within 15 minutes," Snell said.

In California, Pacific Gas and Electric has faced massive liability claims from fires, and now preemptively shuts down some power in certain areas when high wind forecasts raise the risk of downed power lines starting fire.

Before this wind event, Portland General Electric also opted to cut off electricity in "a public safety power outage" in a high-risk areas close to Mount Hood. In the future, this utility, as well as others in the Pacific Northwest, could opt for much broader power shut downs if another major wind event is forecast in the dry tail-end of summer.

"... at a loss for words"

Some scientists were blown away by the scope and destruction of the fires.

"I wasn't expecting to see an east wind-driven fire event like this in my life, but here it is," said Daniel Gavin, professor in the Department of Geography at the University of Oregon in Eugene.

The timing of the ignition of Oregon's Holiday Farm fire could not have been worse, coming right as it did at peak wind gusts.

"What is shocking is how quickly these fires went from zero to hundreds of thousands of acres," said Phil Higuera, associate professor of fire ecology in the Department of Ecosystem and Conservation Sciences at University of Montana in Missoula.

That is because of the east wind that blew sparks to flame -- but also the kiln-like conditions created by climate change.

"You can't point to any one fire now and say, 'That is a totally naturally occurring event,'" Higuera said.

Human-caused climate change has nearly doubled the forest-fire area burned from 1984 to 2015, adding 4.2 million acres of charred land in the Western continental U.S., scientists John Abatzoglou and A. Park Williams found in their 2016 paper published in the journal PNAS.

In one sense, the fires burning now are bringing fire back to portions of the landscape that because of landscape change and fire suppression saw a drop in fire activity from the late 1800s through the 1900s.

But the scale of what has been detonated over the last week has shaken even those with scientific detachment and a long-term perspective rooted in knowledge of fire history.

"My gut reaction is that what is happening now is on the edge of unprecedented and it is extraordinary," Higuera said. "I am kind of at a loss for words."