State’s fire season had been mild, but luck may have run out
The Oak fire, burning through rural communities in Mariposa County about 10miles west of Yosemite National Park, is the kind of fast-moving blaze that firefighters had been worried about as California struggles through a third year of severe drought.
It might seem like a commonplace event after several years of record wildfires. But until the Oak Fire began on Friday, the state was off to a surprisingly promising start to this summer’s wildfire season.
A Bay Area News Group analysis of data from the National Interagency Fire Center in Boise found that just 33,592 acres burned statewide from Jan.1 to July 19 on federal, state and privately owned lands. That’s the lowest total over that time since 2009, and the third-lowest in the past 20 years.
How long the Oak fire will burn is unknown. But risks statewide are certain to increase, fire experts say, as summer continues.
California has struggled with drought over eight of the last 11 years. Climate change is making heat waves hotter. Millions of dead trees and brush remain ripe to burn, from the Sierra to the Bay Area, the Santa Cruz Mountains to Southern California. Add to that, significant rain doesn’t fall most years in California until October or November.
“People shouldn’t get complacent,” said Isaac Sanchez, a battalion chief with Cal Fire. “If this was a baseball game, we are in the middle innings. There are still a lot of dry months to come.”
By Sunday, the Oak fire had grown to 14,281 acres with 0% containment. Flames had burned at least 10 homes and other structures in the Midpines area as residents evacuated. Police closed Highway 140 and massive columns of smoke poured off the landscape in what had become the most ominous fire of the year so far.
Until this past weekend, the largest fire of the year in California had been the relatively small Washburn fire, which began July 7 near the Mariposa Grove in Yosemite. Sunday it was 79% contained, having burned 4,857 acres. More than 1,300 firefighters, aided by 50 years of controlled burns in the famed giant sequoia grove that helped moderate the flames, saved the day. No homes were destroyed. No lives were lost. And no old-growth giant sequoias were killed.
The reasons for the mild start to the 2022 fire season?
Following a record-dry January, February and March, a fair amount of rain and snow fell in April. The Northern Sierra received just 11% of normal precipitation for those first three months, then got 6.1 inches in April — twice as much as the previous three months combined, and well above the historical April average of 4.3 inches.
It also rained a few times in June. Not enough to break the drought or fill reservoirs, but enough to increase soil moisture and boost moisture levels in grasses, plants and shrubs.
Add to that, the first three weeks of July were cooler than normal in California. Although the state had several heat waves in March and early April, in recent weeks a trough of low pressure off the West Coast kept California’s temperatures down while high-pressure ridges in other parts of the country caused record heat waves from Texas to the East Coast.
And there haven’t been freak dry lightning storms. Such storms set off hundreds of fires in 2008. That year, by July 5, there were 328 wildfires burning at the same time. Former Gov. Arnold Schwarzenegger called in National Guard troops to help, and firefighters from Greece, Cyprus, Chile, Argentina, Brazil, Australia, Canada, Mexico and New Zealand fought the blazes.
A similar wave of dry lightning in August 2020 sparked ferocious blazes that leveled more than 5,000 structures from the Santa Cruz Mountains to Wine Country to the Diablo Range east of San Jose, and killed more than 25 people.
So far this year, the lightning hasn’t arrived.
“It’s been a lucky confluence of events,” said meteorologist Jan Null, with Golden Gate Weather Services in Half Moon Bay. “But it’s too early for the state to be patting itself on the back. We still have four dry months ahead.”
When fires have started, the state’s main firefighting agency, Cal Fire, and the U.S. Forest Service along with other agencies have attacked them with large numbers of aircraft and firefighters.
“Cal Fire is kicking ass,” said Craig Clements, director of San Jose State University’s Fire Weather Lab. “They are really on top of it. They are putting a lot of resources on fires early.”
Although California has seen the third-fewest number of acres burn so far this summer in 20 years, records show that 4,576 fires started between Jan. 1 and July 19. That’s the sixth-most in the past 20 years. In other words, lots of fires are starting. But until the Oak fire, which began on a hot Sierra afternoon in oak woodlands that haven’t burned in generations, they weren’t spreading into major conflagrations.
Thursday, a fire broke out in eucalyptus groves near Aromas, by the San Benito-Santa Clara county border. Within an hour, commanders on the incident, called the Anzar fire, had called in a massive DC-10 air tanker from Sacramento to drop retardant on the flames, along with helicopters and 35 engines. The fire, which could have reached Highway 101, on Sunday was 70% contained and halted at 104 acres.
The recent favorable weather is likely to shift. Daniel Swain, a climate scientist with UCLA, noted Friday that higher temperatures are forecast next week in the Pacific Northwest and parts of California.
“Fire season is going to heat up in the Sierra Nevada and northern mountains this week,” Swain said. “It might be a few more weeks before it does along the coast. But I think we are going to start seeing bigger fires.”