The National Weather Service (NWS) has issued a flood watch for recently burned areas in Southern California from Sunday at 4 p.m. to Monday at 4 p.m.
The watch covers several major burn scars, including the Eaton, Palisades, Franklin, Hughes, and Bridge fire areas, amid increasing concern about potential debris flows.
Newsweek has reached out to the NWS via email for comment on Saturday afternoon.
Why It Matters
Southern California faces its first significant rain of the winter following a series of devastating wildfires that have left the region vulnerable to flooding.
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The Palisades fire, now 81 percent contained, has burned more than 23,400 acres, destroyed 6,809 structures and claimed 11 lives.
The Eaton fire has proven even more destructive, burning over 14,000 acres, destroying 9,418 structures, and resulting in 17 fatalities despite reaching 95 percent containment.
The Hughes fire, while smaller at 10,400 acres and 87 percent containment, adds to the region’s vulnerable burn areas.
Stock image: Vehicles travel toward downtown as rain continues to fall during the morning commute as a powerful long-duration atmospheric river storm impacts Southern California on February 6, 2024 in Los Angeles, California. Stock image: Vehicles travel toward downtown as rain continues to fall during the morning commute as a powerful long-duration atmospheric river storm impacts Southern California on February 6, 2024 in Los Angeles, California.
What To Know
According to the NWS, rainfall totals will vary significantly across the region, with mountain areas receiving up to two inches while other areas may see as little as a quarter inch.
Regular rainfall rates will typically range from one-tenth to one-quarter inch per hour, though isolated areas could experience rates up to three-quarters of an inch per hour—sufficient to trigger debris flows in burn areas.
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The probability of significant flash flooding and debris flows in the most vulnerable areas has doubled from the initial forecast, now standing at 10 percent to 20 percent.
Additional hazards include possible thunderstorms, small hail, and wind gusts reaching 60 mph in the Antelope Valley foothills.
What Is Debris Flow?
Debris flows represent the most dangerous form of landslides, consisting of powerful mixtures of mud, rocks, boulders, trees, and sometimes even homes or vehicles, according to the NWS.
While often called mudslides or mudflows, debris flows pose a unique threat due to their devastating power. They can occur during intense rainfall after wildfires, requiring only a brief period of heavy rain—about half an inch in an hour—rather than prolonged precipitation.
Their unpredictable nature and rapid speed make them particularly hazardous, as they can outpace both pedestrians and vehicles.
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Traditional protective measures like sandbags and retaining walls prove ineffective against these powerful flows, making evacuation the only reliable safety measure.
What People Are Saying
National Weather Service Office in Oxnard: “The threat is high enough to prepare for the worst-case scenario.”
Ryan Kittell, National Weather Service Meteorologist told the LA Times: “They’re some of the freshest burn scars. They’re close to communities and/or vulnerable infrastructure. And the orientation of the terrain would favor those areas, in particular, having the higher chances, the higher potentials, for those higher totals and rainfall intensities.”
Alex Tardy, National Weather Service San Diego Meteorologist: “This is a slow-moving storm, so it’s going to be stubborn. It’s going to hang around. It’s going to send waves of moisture through Monday. So, I think that’s really going to add up to significant rain and snow.”
A low-pressure system from the north will bring colder temperatures and rain chances to southern California as early as Saturday afternoon, lasting into Monday. Credit: NWS A low-pressure system from the north will bring colder temperatures and rain chances to southern California as early as Saturday afternoon, lasting into Monday. Credit: NWS
What Happens Next
The NWS urges residents to avoid recently burned areas during the high-risk period, particularly from Sunday afternoon through Monday.
Emergency preparedness recommendations include maintaining adequate supplies in case of road access disruption.
California air quality officials have sued four truck manufacturers for breaching a voluntary agreement to follow the state’s nation-leading emissions rules, the state announced Tuesday.
What happened: Attorney General Rob Bonta’s office filed a complaint Monday in Alameda County Superior Court, arguing that the country’s four largest truck-makers — Daimler Truck North America, International Motors, Paccar and Volvo North America — violated an enforceable contract that they signed with the California Air Resources Board in 2023.
The lawsuit comes two months after the manufacturers filed their own complaint in federal court, arguing the agreement — known as the Clean Truck Partnership — is no longer valid after Republicans overturned California’s Advanced Clean Truck rule in June through the Congressional Review Act.
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Why it matters: The move sets up a fight to determine whether the federal system or state courts — where CARB would have a higher likelihood of prevailing — will review the case.
California, along with other states, has filed a lawsuit against the U.S. Department of Agriculture and Secretary Brooke Rollins for halting SNAP benefits, cutting off food aid for over 41 million Americans, according to Attorney General Rob Bonta.
About 85% of elementary schools studied in California experienced some loss of trees between 2018 and 2022, according to a paper from the University of California, Davis, published this month in the journal Urban Forestry and Urban Greening.
Members of the UC Davis Urban Science Lab found that while the average decline was less than 2%, some districts in the Central Valley — including schools with few trees to lose — lost up to a quarter of their tree cover. The most severe losses were concentrated in Tulare County, while the most notable gains were found in Imperial County.
This map, figure 2B from the study, illustrates the net change in tree canopy cover at urban school districts between 2018 and 2022. Canopy losses tended to cluster in the Central Valley and parts of Southern California. (UC Davis)
The findings are troubling as climate change will likely intensify extreme heat and drought conditions. The study underscores an urgent need to improve tree canopy in low-shade, high-need schools and to protect existing tree cover in areas facing loss.
“We are trying to measure to what extent we are exposing kids to temperatures that might be stressing their body to a level that becomes uncomfortable or dangerous,” said Alessandro Ossola, an associate professor of plant sciences who directs the Urban Science Lab at UC Davis.
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The team continued the research this past summer at elementary schools across the state, measuring tree canopies and maximum temperatures at playgrounds, basketball courts, soccer fields and other outdoor spaces.
UC Davis researchers discovered California school playgrounds are hitting a scorching 120°F heat index. Watch as they use high-tech sensors and a roving cart named MaRTyna to measure extreme heat across elementary schools. (Jael Mackendorf/UC Davis)
Tree canopies cover only about 4% to 6% of the average California school campus. That means the roughly 5.8 million K-12 public school students in California often take breaks and participate in outdoor activities under the glaring sun.
As part of the work, researchers mapped tree cover and heat over the course of a hot day at schools in inland and coastal areas of Northern and Southern California.
UC Davis student Tyler Reece Wakabayashi works with MaRTyna, a roving cart that measures information related to mean radiant temperature and other data points. (Jael Mackendorf /UC Davis)
The research is a joint effort with UC Davis, UC Berkeley and UCLA and is funded by the U.S. Forest Service and supported by the nonprofit Green Schoolyards America through its California Schoolyard Tree Canopy study.
“Most schools are actually a nature desert, which is antithetical because we know that early life exposure of humans to nature is critical for them to develop skills, improve their microbiome, become more environmentally active and so on,” Ossola said. “Trees are a hidden asset and an underutilized asset.”
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This news release is adapted from a longer article from the UC Davis College of Agricultural and Environmental Sciences. Read their full feature story, “Researchers Measure Schoolyard Heat One Step at a Time.”
