A wind-driven wildfire swept through rural and residential communities northwest of Los Angeles, charring more than 20,500 acres and leveling dozens of homes.
The Mountain Fire in Ventura County, California, continued to burn Thursday morning as images showed dozens of structures turned into smoldering ruins that now line the streets where neighborhoods once stood.
Fire officials said at a news conference Thursday evening that an assessment by damage teams found that 132 buildings were destroyed, mostly homes, and 88 buildings were damaged.
“This is a challenging fire and a wind-driven fire. We are still at 0% containment as we continue to focus on life safety and structure defense,” Ventura County Fire Department spokesman Andy VanSciver said during a morning press conference, adding that the county has deployed 10 damage assessment teams to assess street by street to go to count the toll. The fire was 5% under control on Thursday evening.
Related: Californians are forced to flee as intense wildfires destroy homes and buildings
According to the Ventura County Fire Department, hundreds of firefighters battled the blaze throughout the night using both ground resources and helicopters. Officials added that more resources were on the way.
Fanned by high winds with gusts of up to 187 km/h and humidity as low as 8%, the fast-moving fire gave residents little time to flee on Wednesday, prompting frenzied evacuations of more than 10,000 people. About 3,500 homes and businesses remain threatened, officials said.
Many large animals also required rescue as equestrian groups coordinated their efforts online to secure trailers and stalls as fairgrounds and other evacuation areas filled up.
The Santa Anas, the warm, dry winds that typically sweep through Southern California this time of year, were not unexpected. But successive years of strong rainy seasons left these landscapes littered with grasses that turned to tinder after being fried in the summer heat. Combined with low humidity and this region’s natural tendency to burn, the perfect recipe for disaster was to unfold.
“The Mountain Fire is yet another sobering reminder that when you combine our natural chaparral landscapes and strong Santa Ana winds with longer, hotter dry seasons, you have all the ingredients for these devastating events to increase in frequency, scale and speed,” said Dr. Alex. Hall, director of UCLA’s Center for Climate Science, in a statement.
“Unfortunately, it is never a matter of ‘if’, but rather ‘when’ and ‘how big’ when it comes to wildfires in Southern California.”
On Thursday morning, the National Weather Service reported relative humidity was just 10%, with wind gusts of 60 mph in some areas. Warnings of high winds and dense smoke are in effect for certain regions on Thursday.
The red flag warning will remain in effect in most areas through most of Thursday and extend into Friday morning for the same regions, including the inland, coastal slopes of San Bernardino County and the mountain areas of San Diego and Riverside County.
Drew Smith, assistant chief of the LA Fire Department, said the conditions that prompted the red flag warnings were responsible for the fire’s exponential growth. He described how the fire spewed embers that spread the flames up to three miles away. “It makes it very challenging for our firefighters to fight these fires,” he said.
But in an update Thursday morning, the NWS said conditions around where the fire is burning have improved from the day before.
The particularly extreme red flag condition forecast for the area, characterized by critically dry fuels, low humidity and high winds, “was a bit moderate,” said Rich Thompson of the NWS, who spoke to reporters Thursday. “Fortunately, we expect Santa Ana winds to decrease in strength by mid-afternoon,” he added. “Tonight at 6pm we expect the red flag to end across the entire area.”
Acres burned
US wildfires are measured in hectares. While the size of a wildfire does not necessarily correlate with its destructive impact, area provides a way to understand a fire’s footprint and how quickly it has grown.
There are 2.47 acres in an acre, and 640 acres in a square mile, but this can be difficult to visualize. Here are some simple comparisons: One hectare is approximately the size of an American football field. London’s Heathrow Airport covers approximately 3,000 hectares. Manhattan covers approximately 14,600 hectares, while Chicago covers approximately 150,000 hectares and Los Angeles approximately 320,000 hectares.
Megafire
A megafire is defined by the National Interagency Fire Center as a wildfire that has burned more than 100,000 acres.
Containment level
The containment level of a wildfire indicates how much progress the fire brigade has made in controlling the fire. Containment is achieved by creating perimeters that the fire cannot move across. This is done through methods such as laying fire retardants on the ground, digging trenches or removing brush and other flammable fuels.
Containment is measured as the percentage of the fire surrounded by these control lines. A wildfire with a low containment level, such as 0% or 5%, essentially burns out of control. A fire with a high containment level, such as 90%, is not necessarily extinguished, but rather has a large protective perimeter and a growth rate that is under control.
Evacuation orders and warnings
Evacuation warnings and orders are issued by officials when a wildfire poses an immediate danger to human life and property. According to the California Emergency Services Agency, an evacuation warning means it is a good idea to leave an area or prepare to leave quickly. An evacuation order means that you must leave the area immediately.
Red flag warning
A red flag warning is a type of forecast issued by the National Weather Service that indicates when weather conditions are likely to start or spread wildfires. These conditions typically include drought, low humidity, high winds and heat.
Prescribed combustion
A prescribed burn, or a controlled burn, is a fire that is deliberately ignited under carefully managed conditions to improve the health of a landscape. Prescribed burns are performed by trained experts, such as members of the US Forest Service and indigenous firefighters. Prescribed burns help remove flammable vegetation and reduce the risk of larger, more catastrophic fires, among other things.
Prescribed burning was once a common tool among Native American tribes using “good fire” to improve the land, but was limited for much of the last century by a U.S. government approach based on fire suppression. In recent years, U.S. land managers have begun to embrace the benefits of prescribed burns again, and now manage thousands of people across the country every year.
As conditions improve – and especially as the wind decreases – firefighters will be much better able to extinguish the fire.
“Our firefighters are being nothing short of heroic right now,” Ventura County Fire Department Captain Trevor Johnson said Wednesday, noting the extreme and dangerous firefighting conditions.
Due to the high fire danger, Southern California Edison temporarily turned off power to several thousand customers as part of its public safety power shutoff plan to prevent the electrical system from becoming a source of ignition.
Similarly, the Pacific Gas and Electric Company has shut off power to thousands of accounts across the state in an effort to limit the risk of ignitions.
About 3,000 customers were without power in Ventura County and just over 500 in Los Angeles County as of Thursday morning, according to poweroutage.us.
Ventura County Schools also announced that all area schools would be closed on Thursday and Friday.
California Governor Gavin Newsom announced Wednesday that the state has received federal assistance from the Federal Emergency Management Agency to help ensure the availability of critical resources for Ventura County.
“This is a dangerous fire that is spreading quickly and threatening lives,” Newsom said. “State resources have been mobilized to protect communities, and this federal support from the Biden-Harris Administration will give state and local firefighters the tools they need to save lives and property as they continue to battle this aggressive fire. ”
As the climate crisis turns up the dial, creating new dangers and greater risks for disasters like the Mountain Fire, scientists hope lessons can be learned.
“To date, much of the research on managing wildfire risk in California has focused on forested areas, but the Mountain Fire once again underscores the urgent need for strategies tailored to California’s unique landscape, climate and communities. Southern California,” Hall said.
“We hope our work can provide policymakers with the solutions-oriented research they need to make the best decisions to protect our communities and our environment in the face of a changing climate.”
