This story was originally appeared in high altitude news is part of climate desk collaboration.
In Southern California, wildfires in December are somewhat unusual, but not completely unusual. And this year, extremely dry conditions and strong Santa Ana winds created the perfect conditions for dangerous year-end fires.
On the night of December 9th, franklin fire Sparks fly on the hills of Malibu, tear upThey cover approximately 3,000 acres in just 24 hours. As of noon on Dec. 12, the fire was less than 10 percent contained and had burned just over 4,000 acres. 7 structures.
last month, mountain fire A blaze was ignited in nearby Ventura County under similar conditions and grew to 1,000 acres in the first hour. Within two days its area grew to over 20,000 acres. 240 structures were destroyed before firefighters brought it under control in early December.
And we still haven’t had any rain since the wildfires and throughout the entire fall.
Indeed, the Santa Ana winds—the dry winds that blow from the high desert to the coast and bring low humidity, sometimes below 10 percent dryness—regularly intensify throughout the fall and winter. But what is unusual is the lack of precipitation grab Currently, Southern California is not technically in a crisis situation, but drought still.
At the weather station in downtown Los Angeles, recorded Only 5.7 inches of rain has fallen this year, less than a quarter inch in December, which is usually the middle of the region’s rainy season. Most years, there are at least three rainy days by this time of year, enough to moderate the risk of wildfires. Approximately 90% of the region’s rainfall come From October to the end of April.
“We’re still waiting for the rainy season to start in that part of the state, which will wet the fuel considerably and subside the threat of large-scale fires,” he said. John Abatzoglouprofessor of climatology at the University of California, Merced.
Fire danger is lower in wet years and windy seasons. But now, as Abatzoglou says, “when ignition and wind collide,” the landscape is primed for fire. Dry grass and shrubs are ready to burn. fire hazard The Los Angeles County Fire Department’s forecast for Dec. 11, when the fire had significantly expanded, was for high to very warm temperatures across the Los Angeles Basin, Santa Monica Mountains, and Santa Clarita Valley. “It hasn’t rained in Southern California yet this season.” Daniel Swaina climate scientist at UCLA. “That’s the key. That’s the real kicker.”
High winds that coincide with plant death aren’t just a problem in Southern California. Dry conditions increase the risk of wildfires across the country. east coastFor example, the spring and fall fire seasons. And other parts of the West are experiencing winter fires: Fires are burning quickly in Colorado. marshall fire It broke out on December 30, 2021, and in just one hour, it transformed from a small grass fire to a major suburban fire that ultimately destroyed more than 1,000 homes.
