Parched brush breeds extreme fire behavior
CLEARLAKE, Lake County — Scott Upton shook his head in wonder as he drove past ranch lands along a flat section of Highway 20, where the massive Rocky Fire had leaped over helpless firefighters trying to make a stand.
The firefighters had set intentional backfires in an attempt to burn away fuel, but the blaze shot embers across what is known as New Long Valley, igniting the hills on the other side of the road.
Upton, the unit chief for the California Department of Forestry and Fire Protection, scanned the blackened ridges and explained how the fire had burned so hot — in brush dried out by drought — that it generated its own wind like some kind of
fire-breathing dragon.
Upton was describing the conditions that drove the erratic Rocky Fire, but he could just as well have been talking about the entire state. The historic four-year drought has transformed a California that is always fire-prone into something even more dangerous and volatile.
The state’s hills and valleys — made up largely of chaparral, heavy brush, manzanita and oak — are as dry as they have ever been, according to laboratory measurements of moisture. The studies, done every year by state forestry biologists, show fuel moisture lower than levels normally seen in September and October, the driest time of the year.
“See up those ridges where there is nothing left?” said Upton, pointing to a huge finger of hillside burned to ash next to an unburned tangle of green, forest-like brush. “That’s called chemise brush. We call it standing gasoline.”
Chemise, one of the fuels used for the Northern California measurements, is “pretty darn close to the minimums ever recorded since 1992,” said Eric Hoffmann, the assistant northern region chief for Cal Fire and a fuels expert. “The line is pretty much touching the minimum ever. That’s pretty dry (and) it’s pretty typical across the state.”
The dryness of the fuel, fire experts say, explains why the 70,000-acre Rocky Fire burned so hot and sent smoke plumes 35,000 feet into the atmosphere, then blew out embers as if from a cannon. These enormous plumes, known as pyrocumulus clouds, are usually seen only in large timber fires, where flames shoot up to the crowns of the trees, creating a rising vacuum of hot air that generates its own wind.
“It is unusual,” said Max Moritz, a fire scientist at the department of environmental science, policy and management at the UC Berkeley Cooperative Extension. “This exceptional drought creates extreme fire behavior because the fire doesn’t have to work so hard to dry off the moisture. So you have the potential for a much hotter and faster-moving fire.”
The fire-generated wind and weather made the Rocky Fire chaotic and hard to control, said Marshall Turbeville, a battalion chief and fire behavior analyst with Cal Fire. He said the same dynamic was at work in the King Fire, in the foothills east of Sacramento last summer, and the Rim Fire, which burned 257,314 acres in the Sierra in 2013, the third-largest wildfire in California history.
Such fires, which can send smoke clouds so high that ice forms at the top, render useless many of the standard firefighting tactics, like cutting firebreaks, spraying water, dropping retardant and bulldozing away fuel. “That’s what is really concerning,” Turbeville said.
The danger is clear in how many more wildfires have broken out in California this year compared with the past five years. As of Wednesday, 6,040 fires had burned 195,778 acres. In 2011, the year before the drought began, 3,969 fires burned 69,287 acres in the same
time period, according to the U.S. Forest Service.
And as the number of fires continues to rise, the cost of fighting them has been spiraling out of control.
The Forest Service issued a report Wednesday saying that, for the first time in its history, it was spending more than half of its $5 billion annual budget battling wildfires. That’s compared to 16 percent just 20 years ago — and it means other efforts like forest restoration and watershed management are getting short shrift.
Cal Fire’s expenditures have also spiked, with the department spending $63 million since July 1, when the fiscal year began. The budget this year is $392 million, which may not be enough even though Cal Fire’s budget has historically hovered around $209 million.
Lynne Tolmachoff, a spokeswoman for Cal Fire, said the agency spent more than its budget last year despite receiving $110 million extra to fight fires after Gov. Jerry Brown declared a drought emergency.
“We can budget all we want, but it’s up to the fire season to determine where it goes, and this fire season is looking pretty rough,” she said.
Scientists have long predicted an increase in fire intensity and frequency in California as a result of climate change. The Forest Service report declared that winters are already shorter and that fire season is now 78 days longer than it was in the 1970s. As a result, at least 10 states have, since 2000, experienced their largest fires on record.
Before Europeans arrived in California, fires were common in the state and served to cleanse the forests of excess underbrush, according to forestry experts. Fire management has since become so effective that 98 percent of all blazes are put out. That has left vast quantities of brush and undergrowth in California forests.
Researchers believe the Rim Fire burned faster and hotter because of the high density of trees and abundant wood debris on the forest floor.
The suppression of fire has also apparently contributed to the spread of sudden oak death. The disease, known as Phytophthora ramorum, uses bay trees as its primary host, spreading spores around the forest. Without any fires to control their growth, scientists say, bay trees are multiplying and their understory competitors — tan oak, toyon, madrone — are being killed by the disease.
The drought has had consequences beyond drying out fuel. It is being blamed for a bark beetle outbreak that has ravaged pine trees throughout California, leaving fire-prone dead wood standing virtually everywhere.
With the land ripe for conflagrations, forestry officials are keeping a sharp eye out for lightning fires, even sending patrols into the mountains to tamp out fires after electrical storms pass through.
Ryan Walbrun, a fire weather meteorologist for the National Weather Service, said the River Complex Fire in Trinity County started last week as 18 separate fires ignited by dry lightning. All the fires now burning in Trinity, Humboldt and Del Norte counties were caused by lightning, which followed a heat wave in the area that dried things out even further.
“It’s not so much that we are getting more or less lightning. It’s what the conditions are when that lightning occurs,” Walbrun said. “You take the long-term drought, and if you have a record heat event and you throw some lightning onto it, it doesn’t take Einstein to figure out that that’s a pretty bad recipe.”
Lightning has ignited some of the state’s most devastating fires. In 2008, more than 2,500 lightning strikes started hundreds of fires that were so smoky that the sun was blotted out in portions of Northern California. Lightning strikes also caused fires in 1977 and in 1987, both dry years like this one.
The scary thing, Upton and others say, is that California’s fire danger will only get more extreme over the next two months when winds, like the Santa Anas in the south, begin blowing outward toward the sea. Most of California’s biggest and most catastrophic fires have been driven by such winds.
“I’d say it’s a real worry, a serious worry,” Moritz said. “Most of us doing fire-related research see that because the landscape is so primed, so flammable, the stage is set for some very bad events.”