‘Intense’ burning feared for state
The chamise plants that blanket California’s shrubby chaparral should have grown new sprouts by now, flowering after winter rains before baking in the arid summer heat.
They are highly flammable and abundant in wildland areas — and, for that reason, a bellwether to wildfire researchers. This month, a San Jose State University team analyzing moisture levels was shocked at what it found at study sites in the Santa Cruz Mountains.
At two locations researchers found no new growth to cut from the shrubs. It’s an ominous sign of just how dry the vegetation is around California, where boundless numbers of plants and trees have been starved of lifesustaining water thanks to an entire winter of paltry precipitation. Those dry plants are fuel for wildfires, and they’re primed to burn explosively.
Craig Clements, director of San Jose State’s Fire Weather Research Laboratory, said it was the first time he had ever found no new chamise growth to study. The plants are about as dry as they would normally be a few months from now, he said.
“The chamise was really, really problematic,” Clements recalled. “They’re not bringing enough soil moisture up into their woody stems to grow. They’re remaining somewhat dormant.” To him, the implications are clear. “We could have more intense fires earlier in the season, is what it suggests,” Clements said.
California is barreling toward its driest and most fireprone months, with many loca
tions around the Bay Area and Central Coast having seen about 50% or less of their average precipitation levels for this time of year. And the time for improvement is rapidly ending, as the state’s Mediterranean climate leaves essentially zero room for any substantial amount of rain or snow once April ends.
All but a small slice in the state’s northwest is in some level of drought or, at a minimum, abnormally dry, according to the U.S. Drought Monitor. The parched conditions result from two consecutive winters of abysmal precipitation. State officials have already warned of water supply shortages and pleaded with the public to conserve. At last one Bay Area water district is considering imposing restrictions.
The persistent dryness has already provided ample room for unusual fire activity. A spate of small fires started around Northern California in January, when Pacific Gas and Electric Co. also initiated its firstever wintertime power shutoffs to prevent blazes. From the start of the year through April 4, firefighters in the state have fought 995 fires that burned 3,007 acres — a huge increase from the 697 fires that burned 1,266 acres in the same time period last year.
It’s the opposite of where the state’s fireweary residents would like to be after the unceasing flames that burned last summer and fall, at one point turning the Bay Area skies deep orange because so much smoke had blocked the sun. A record 4.2 million acres burned in California in 2020.
April’s outlook suggests little reprieve is in store during the warmer months ahead.
“It’s extraordinary that there’s any fire risk in a lot of California right now, and yet here we are,” said UCLA climate scientist Daniel Swain. “Normally, this would be the least flammable time of year throughout most of California.”
Swain said the 2021 fire season is unlikely to surpass the severity of 2020, given the particularly unlucky combination of factors — little rain, a freak August lightning storm and unrelenting autumn winds — that made last year so bad.
“It was just such an extreme, anomalous outlier,” he said. “I think it’s statistically unlikely that we achieve that level, partly because it took a bunch of things coming together in the worst possible way.”
Scientists broadly agree that climate change is elevating California’s wildfire risks, as rising temperatures dry out vegetation and shift precipitation patterns. Of particular concern to Swain is recent research showing how California’s wet season is starting later, thereby extending the tail end of peak fire season.
In a February commentary in Geophysical Research Letters, Swain wrote that the “growing correspondence” between the projections of climate models and actual precipitation in California “increasingly suggests these trends are unlikely to have arisen by random chance, and will likely continue in the future with further climate warming.”
Swain said he’s not yet worried about the intensity of wildfires over the next two months or so, but starting around midJuly, the risk of extreme fire behavior could escalate. The threat could be compounded if autumn rains are again delayed into November or even December — especially when fast, dry winds blow from the northeast.
Those conditions have given rise to some of California’s worst wildfires, including the November 2018 Camp Fire that virtually leveled the town of Paradise in Butte County.
In the Santa Cruz Mountains, the 2020 fire season never truly ended. The area was hit hard in August by the 86,000acre CZU Lightning Complex fires, which killed one person and destroyed about 1,000 homes in Santa Cruz and San Mateo counties. Some of the anomalous January fires were within the footprint of the CZU burn scar, suggesting that winds whipped up embers that had smoldered into winter.
Another “sleeper spot” in the CZU burn scar was responsible for one of five fires extinguished by Cal Fire since the end of March. Several others were started by escaped controlled burn piles, officials said. Some required aircraft to suppress — a step not normally needed until June.
Though the blazes burned just a handful of acres, the fact they were able to gain any traction at all alarmed firefighters, who have now sped up their seasonal staffing increases.
“With the lack of precipitation, it’s very concerning,” said Ian Larkin, unit chief of Cal Fire’s San MateoSanta Cruz Unit. “We are a month ahead of schedule on our staffing.”
The state government has tried to get ahead of the looming threat by adding 1,400 firefighters and unveiling a $536 million plan to fund vegetation thinning, forest health initiatives, grants to make homes fire resistant and other measures.
Speaking about the plan on Thursday at Fresno County’s Shaver Lake, where the monstrous Creek Fire ignited in September, state Natural Resources Agency Director Wade Crowfoot said, “We are just getting out of our second consecutive dry winter, and what we can expect this summer in wildfire conditions is more of the same.”
That’s an unsettling reality for parts of the state that have been repeatedly battered by fires in recent years. One of them is Sonoma County, which was hit by major wildfires in 2017, 2019 and 2020. Santa Rosa, the county’s largest city, had by early April recorded just 40% of its average rainfall for this time of year.
Another indication of the widespread dryness: County water managers said reservoir capacities are lower than they were at the height of the last drought.
“The general trend is, nothing is looking good,” said Marshall Turbeville, chief of the Northern Sonoma County Fire Protection District.
Turbeville said his greatest concern is forested areas, even though some of them just burned last year during the Walbridge Fire, which made up the west portion of the North Bay’s gargantuan LNU Lightning Complex.
“It’s gonna be the conifers, where those big logs are just not having the opportunity to accrue the wintertime moisture,” he said. “I’m really worried about forest fires.”
But the year’s wildfire outlook is embedded with uncertainty. Dryness and heat aside, all wildfires need a spark, often caused by a human. No one can predict if and when the sparks will occur. In any case, Swain, the UCLA climate scientist, said the state will hopefully not endure an extremely rare dry lightning siege two years in a row, which would eliminate nature’s most menacing ignition source.
Perhaps the greatest unknown is the force behind the deadliest of recent fiery catastrophes: the powerful gusts that propelled flames into places such as Santa Rosa and Paradise. Their frequency and severity are impossible to ascertain several months in advance. As always, the wind will be the wild card.