Experts are warning Californians to prepare for a “very active” wildfire season this fall, as two consecutive rainy seasons are forecast for now and into next year. hotter than normal summers The possibility of fire has increased in the state.
Even so People were evacuated due to the recent fire In Los Angeles and Sonoma counties, these events may be relatively rare compared to the rest of the year, said Daniel Swain, a UCLA climate scientist and extreme weather expert.
“We could actually see a very active end to the fire season in 2024, but we’re not there yet,” Swain said during an interview. Briefing Monday,
Dense vegetation nourished by record and near-record rainfall over the past two years will slowly dry out and wither in the hot summer — a process known as “fuel loading.” Although this drying has begun at lower elevations, it has not yet occurred at higher elevations — where some The worst wildfires in recent history These areas are still moist from recent rain and snowfall, but are likely to become drier and more flammable by the end of summer.
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“The good news is slowly outpacing the good news,” Swain said. “The bad news is that I think the back half of the season is going to be much more active — with wildfire activity levels in many areas being far more concerning than the first half.”
He said the “transition point” is likely to occur in July at lower elevations and in August at higher elevations. But fire activity could continue into September, October and possibly even November, increasing in intensity as the season progresses.
(latest Seasonal outlook (Forecasts from the National Oceanic and Atmospheric Administration indicate that June, July and August will be warmer than normal for California and much of the country.)
The forecast comes as crews continue to battle more than 15 active fires across the state, including one that burned 15,000 acres. After the fire In Los Angeles and Ventura counties, fires were fueled by strong winds and dry grasses.
Forecaster for the California Department of Forestry and Fire Protection Below-normal fire activity is expected in June and July along the Southern California coast and mountains and the Sierra Nevada, and near-normal activity in August. However, that is likely to change in September, as the agency forecasts above-normal fire activity.
“That doesn’t mean there’s no potential for catastrophic vegetation fires — it just means that fuel conditions are telling us that activity is potentially going to be below normal through July,” said Isaac Sanchez, deputy chief of communications for Cal Fire. “When you get into August, things start to kind of ramp back up again.”
He said the crews are gearing up for a busy season.
“We have to expect that things are going to be busier than they are now, and they’re going to be worse. Really, that’s the only way we can be prepared to aggressively fight these kinds of fires.”
Recently, fire officials in Southern California made a similar prediction.
“The rain has caused large fields of greenery to grow across the region, and this year we’ve seen areas that have received nearly 200% more rain than normal,” Los Angeles County Fire Chief Anthony Marrone told reporters Friday. “Unfortunately, this vegetation will soon dry out and become fuel for wildfires, especially in the Santa Monica Mountains, Santa Clarita Valley and Antelope Valley.”
He referred to Woolsey fire of 2018 And he sees the 2020 Bobcat fire as an example of “why we can’t let our guard down.” The Woolsey fire killed three people, burned nearly 100,000 acres and destroyed more than 1,600 structures in and around Malibu. The Bobcat fire burned 116,000 acres in and around Angeles National Forest Mount Wilson Observatory almost burned down,
“This year’s fire season could be just as devastating,” Marron said.
But there are other factors involved, too, including: The current transition from El Niño to La NiñaLa Niña is associated with dry conditions along the West Coast and especially in Southern California. La Niña was last present during the state’s three driest years, 2020 to 2022, which also saw heavy rainfall. Record area lit,
Climate change is also a reason warmer global temperatures And a thirstier atmosphere could both draw more water out of the landscape and pave the way for hotter and more intense fires in the West and other dry regions, Swain said.
In fact, he said the recent cycling between wet and dry conditions the state has seen is in some ways the worst-case scenario for wildfire activity in a warming world.
“You get a lot of extreme fires, and then when it gets wetter you let a lot of the vegetation stop and regrow, and then when it dries out you burn it back down again,” he said.
He said he had not made such predictions for active seasons during the past two years, which were dominated by atmospheric rivers, flooding and heavy snowfall and produced relatively mild wildfire activity.
“This is a season that I expect to see a return to fire activity across much of California and the West — maybe a little less in the very high elevations, but everywhere else, we’ll see a significant increase in fire activity this year compared to the last few years,” Swain said.
