One of the most frightening days in Palo Alto Fire Chief Geoffrey Blackshire's career came on a sunny, warm June afternoon in 2014. The call came at 2:13 p.m. A driver rounding a hairpin turn on a mountainous stretch of Page Mill Road had tried to avoid a deer. The car swerved and then plowed head-on into an embankment, bursting into flames.

The dry grasses and brush in the oak-filled woodland at the Foothills Open Space Preserve were set ablaze, and the fire was moving at a moderate speed. All of the conditions were ripe for a fire that could have blown up into a major conflagration — save for the lack of wind.

When Blackshire, who was then a battalion chief, and his crews arrived, the blaze had spread to 1.5 acres. Thankfully, firefighters were able to contain it.

For Blackshire, the fire was a cautionary tale of how the vagaries of nature can either cause a wildfire to spread uncontrollably — or spare a community from burning. Two factors contributed to the fire's quick containment that day: the air was mercifully calm instead of the predicted 18 mph, and the city had opened Foothills Fire Station 8 early.

"There was zero wind. All it would take is for the wind to blow and the fire would have taken off. It was in the heart of a lot of vegetation there," he said in 2014.

California's wildfire "season" isn't seasonal anymore. With climate change producing drier vegetation and hotter weather, it's year-round, experts said.

In an April 9 report to the Santa Clara County Board of Supervisors, county Fire Chief Tony Bowden wrote that the last 10 fire seasons have produced seven of California's most destructive wildland fires.

"It is clear we are seeing unprecedented fire behavior and destruction and need to take immediate action to reduce our risk and ensure Santa Clara County can respond effectively to the 'new normal,'" he said.

Blackshire agreed.

"We're in an era of megafires," he said during a recent phone interview. "Fifteen to 20 of the largest fires in state history are post-2000. We have to adapt to this climate change."

"It can happen here," he said. "To think that it can't would be irresponsible."

A change in the land

The forested slopes and grasslands of the Santa Cruz Mountains haven't experienced a big wildfire since 1912, according to the California Department of Forestry and Fire Protection (Cal Fire) data. Higher air-moisture levels, fog, cooler temperatures and close proximity of firefighting forces have helped to keep a devastating fire at bay, local experts said. But that's changing.

Land use and management practices such as suppressing natural fires, along with greater human activity in the coastal foothills and mountains, are increasing the chances that larger wildfires will occur, fire agency leaders said. Approximately 85% of wildfires are sparked by the actions of people, according to the U.S. Forest Service and the National Interagency Fire Center.

A 2016 map in the Santa Clara County Community Wildfire Protection Plan shows the risks of humans living in and near wildlands: The locations of wildfires have migrated over time, from remote areas pre-1900 toward urban centers in Santa Clara County. Dozens of fires after 2010 have occurred closer to urban areas where fires were not previously recorded in significant numbers.

Like much of the foothills and mountains west of Interstate 280, Palo Alto's open space areas are rated an "extreme" risk, according to an assessment in the county wildfire plan. Abundant grasslands in and around Pearson-Arastradero Preserve are primed for fires that would run along the ground. A sizable portion of Foothills Park has trees that could torch individually like candles, according to the county protection plan. Embers from those flaming trees can travel long distances, igniting fences, homes, businesses and sparking new wildland fires, which when joined, can burn out of control.

Findings in Palo Alto's 2016 updated Foothills Fire Management Plan, which ran computer models of fire behavior under extreme weather conditions, are sobering.

"There is very little in the landscape that does not burn," the report stated, noting that flames could reach 213 feet tall.

So far, the area has been lucky. But wind, combined with sparks and dry vegetation, has fire agencies and some researchers worried.

According to the 2018 California Fourth Climate Change Assessment, dry, warm air flowing to the coast is playing a key role in amplifying "fire weather" conditions. In October 2017, such wind fanned fires that led to enormous damage in Sonoma and Napa counties.

In October, gusts of up to 102 miles per hour fed the Kincade Fire in Sonoma County, according to some weather reports.

On the San Francisco Peninsula, the northeast wind comes across the bay into Palo Alto and up into the foothills — keeping the area safer than places like Paradise. But the wind isn't predictable.

"It can come the other way, especially as the seasons change," said Patty Ciesla, executive director of the Santa Clara County Fire Safe Council.

"The wind can drive the fires so hard and fast that firefighters can't get to them without danger to themselves," she said. "My fear is, we'll have an alignment where the fire is able to blow with such speed and ferociousness we can't do anything about it."

Hotter winds, regardless of their strength, also dry out vegetation. And more than a century of fire-suppression practices have provided the fuel for major conflagrations, said Bill Murphy, fire captain for Santa Clara County Fire Department.

"Landscapes 100 years ago had drastically less fuel than are on hillsides today. We are seeing some of the lowest fuel moistures ever recorded. When you get fire in that environment, it's a recipe for disaster.

"Fire is a form of energy. The more fuel, the more energy can be released. Irrespective of wind, if enough energy is released, the fire is going to move. It is generating tremendous convective energy," he said.

Land managers and fire agencies are scrambling to reduce the fuel loads in forests and grasslands that lead to large-scale fires, which won't prevent them but might drastically reduce them, they said.

In any event, Blackshire said that it will take everyone — the public, land managers, fire departments, park rangers, cities, government agencies, utilities companies — working together to keep ahead of potential wildfires to come.

Focusing on the best defense

The problem is so vast that land managers and fire agencies must pick their battles, they said. Their most important strategy is to create and maintain "defensible space" against fires — areas around a building or road where vegetation, debris or combustible materials are cleared to slow the spread of fire.

Local agencies are focused on several areas: around schools, power stations, hospitals and other crucial infrastructure and a roughly half-mile-wide swath between wildlands and inhabited areas.

Evacuation routes are at the top of the list for clearing. The city of Palo Alto, Santa Clara County Fire Safe Council and Cal Fire all work to reduce undergrowth and overhanging branches along critical roadways. Many routes in the Santa Cruz Mountains have only one way in or out. A fire spreading across the tree canopy to both sides of a road would form a fire tunnel, preventing people from escaping and emergency responders from getting into the area, agency managers said.

As of 2016, the city of Palo Alto reported in an updated Foothills Fire Management Plan that evacuation routes on Arastradero, Page Mill and Los Trancos roads, within and south of Foothills Park and west and east of Pearson-Arastradero Preserve had been cleared. Based on modeling the city did to estimate the impact of the work, under extreme dry-weather conditions with wind blowing uphill at 20 miles per hour, flames that would have been 9 feet tall would only rise 2 feet. The fire's spread would move five times more slowly.

The Fire Safe Council has helped crews manage vegetation along Page Mill and Arastradero, cutting back vegetation 30 feet from the road edge and 10 feet from the ground, Ciesla said.

This year, the council is working with Caltrans and Santa Clara County Fire Department on a particularly dangerous part of State Route 17, cleaning out the dead wood that, in a fire, might make the road impassable. The crews remove shrubs and grasses and churn the soil from the roadside edge up a steep hillside and away from utility poles. With very little vegetation left on the ground but still enough to hold the soil and prevent mudslides, "flames hopefully will not be very tall or very hot, and it will be more like being next to a fireplace," Ciesla said.

Midpeninsula Regional Open Space District, Palo Alto's Foothills Park and Stanford University are also creating similar "defensible spaces" on their lands with a variety of tools: from shovels to graders, mowers to chainsaws, and goats that graze to controlled fires, which burn off dry vegetation. Read more in "Preventing disasters in open space preserves" and "At Stanford, a complex wildlands-fire scenario."

Midpeninsula Open Space District spokeswoman Leigh Ann Gessner said the district currently allows grazing animals on 11,000 of its preserves' 65,000 acres. The grazing helps control invasive weeds and reduces the amount of flammable vegetation.

Even the best-laid plans

All of the agencies will require one critical thing to achieve their plan goals: funding. The state began making investments, but it will take billions of dollars to reduce wildfire threats, fire experts said.

In 2018, former Gov. Jerry Brown signed a $1.1 billion package to clear forests of dry vegetation over the next five years.

Gov. Gavin Newsom in July signed a catastrophic wildfire and safety bill. In October, spurred by a new round of devastating wildfires, he signed 22 bills based on recommendations from the Governor's Strike Force Report of Wildfires.

Newsom approved another $1 billion in the state budget for preparedness and the state's capacity to respond to emergencies. The budget included 13 new fire engines, and a $127.2 million investment to expand Cal Fire's fleet with C-130 air tankers and modified Black Hawk helicopters for nighttime firefighting.

Newsom also signed an executive order authorizing nearly 400 seasonal firefighters to Cal Fire this year. Another $210 million from the Greenhouse Gas Reduction Fund will help Cal Fire complete more fuel-reduction projects, among other efforts.

Other bills will develop models for defensible space and standards for home hardening and construction materials to increase community fire safety and require investor-owned utilities to include information about undergrounding utility lines in their wildfire mitigation plans.

Santa Clara County's Board of Supervisors is considering spending $1.3 million on fighting wildfires. In April, the supervisors received a work plan by the Santa Clara County Fire Marshal's Office, which estimated a need for $1.2 million in fiscal year 2019-2020 and $1.3 million in fiscal year 2020-2021 for fire-fighting vehicles and 10 wildland fire cameras to help spot fires when they start.

Future costs could include an estimated $5.5 million for personnel and equipment for managing vegetation and curtailing fires. The work plan also adds an estimated $7 million to the program's wishlist for a refurbished helicopter.

One wildcard in preventing wildfires, of course, is Pacific Gas and Electric Company (PG&E). Throughout its system, the utility company has approximately 81,000 miles of overhead distribution lines and approximately 26,000 miles of underground distribution lines, which transmit electricity from substations to customers. PG&E's electric transmission system from power plants to substations is about 18,000 miles, the majority of which are overhead lines, the company noted.

Putting the utility's overhead lines underground would cost $3 million per mile, according to a PG&E fact sheet, totaling $297 billion.

Under the California Public Utilities Commission Electric Rule 20A, the utility company is supposed to dedicate funds for undergrounding its overhead lines. An audit of PG&E published Oct. 15 found that the company has underspent commission-adopted amounts by $123 million since 2007, yet the funding for undergrounding was embedded in ratepayers' electric bills.

With literally miles to go in the effort to make the Bay Area safe from wildfires, Blackshire said that people will have to adapt to the new reality. Already, residents and businesses are facing repeated electrical shut-offs during "red flag" weather warnings, he said. It might be necessary to have pre-emptive evacuations instead of waiting until fire breaks out because when the wind whips in the night, danger rises, he said.

Blackshire said many questions about wildfire prevention are still unanswered: how to allocate fire personnel and equipment to fight multiple fires at once and how to prepare for more and greater fires. Fire crews, too, must adapt, and agencies must prepare to supply them with aid and counseling.

"The fires are taking a toll on firefighters. It takes an emotional and physical toll," he said, noting the lingering effects of witnessing heartbroken residents standing amid the smoldering ruins of their homes.

Part of adaptation also requires acceptance that change is here and is likely to continue.

"As we adapt more, we can acknowledge there is a change," he said.

Murphy agreed.

"We have to rethink land management. We didn't get into the problem overnight, and we're not going to get out of it overnight," he said.

Related content:

• How to protect your home against wildfire

• Weekly journalists will discuss this issue on an episode of "Behind the Headlines" coming out later today. A link to the show will be posted here, on our YouTube channel and podcast page.