A recent spike in fire activity in California, marked by a large fire that broke out outside San Francisco on Saturday, has officials wondering whether this year’s fire season could be worse than expected. However, the forecast is complicated by a combination of factors that increase and decrease fire risk.
With plenty of thick grass for fuel, the fire season is off to a much faster start than last year. Several fires are burning across the state and a looming heat wave in the West could further increase fire risk. However, experts still consider the latter part of the fire season, which typically runs from April to October, to be the worst.
The fire that broke out over the weekend, called the Corral Fire, was reported to be 90% contained as of Tuesday morning, after burning more than 5,665.8 hectares. (14,000 acres) in San Joaquin County, just south of Tracy, California. 60 miles east of San Francisco, it is still under investigation.
California’s fire season has become more active in the past two weeks as the hot, dry weather that took hold in May dried out the thick grasses that sprouted during the previous two wet winters. Once a fire starts, gusts of wind can quickly spread flames across dry grasses.
Cal Fire listed eight active fires as of Tuesday morning. While much of the activity is in the central and southern part of the state, the Corral Fire in Northern California is by far the largest fire in the state this year. Driven by gusty winds, that fire burned a home, injured two firefighters and forced thousands of people to evacuate, the Associated Press reported.
Wildfires have burned more than 13,759.8 hectares (34,000 acres) in the state this year, far more than the 3,439.95 hectares (8,500 acres) that normally burned in early June and the 1,011.75 hectares (2,500 acres) ) that were burning this time last year.
For now, fire risk is primarily limited to grasslands during windy conditions. How flammable the rest of the state becomes depends on this summer’s heat and humidity trends. A heat wave expected across much of the state later this week and into the weekend, which is forecast to raise temperatures in central California to near and above 100 degrees, will further decrease the snow cover and will dry out the vegetation. There are mixed signals about how this year’s wildfire season will play out.
In early May, forecasters were anticipating lower fire risk toward the early part of summer after California received a lot of rain and snow during the winter and spring, although predictions of a hot summer and a delayed or weak southwest monsoon They were already generating concern.
While unexpected, the recent increase in fire activity has not necessarily changed the forecast going forward, as forecasters are still balancing competing factors.
On the one hand, drought, which increases the risk of fires, is currently not a major concern after the second stormy winter in a row. Although recent warmth has reduced the state’s snowpack to 44 percent below normal, reservoir levels remain 18 percent above normal after slightly above-average precipitation so far of the year.
“I don’t expect drought at least for the next few months,” said Brent Wachter, a fire meteorologist with the National Weather Service.
On the other hand, abundant vegetation could provide plenty of fuel for fires, as the Corral fire and others have already shown, especially if combined with a dry, hot climate. The Weather Service’s outlook for June, July and August favors above-normal temperatures across the state.
“We have a lot of extra fuel with two wet years in a row, so August could become active, especially if the month of July is expected to be warmer than normal,” said Alex Tardy, a meteorologist with the National Weather Service in San Francisco. Diego. “We are also seeing lower monsoon activity in the West, so combined with repeated heat waves… August to October could be quite active.”
Still, there is a lot of uncertainty in the forecast, and the ongoing fires may throw forecasters another curve ball. “One way to think about early-season grass fires is that the area burned represents one less piece of land that can potentially burn later in the fire season, when conditions are much drier and fire crews they are less available,” Daniel Swain, a climate scientist at UCLA, said in X.
