The Bond Fire in Santiago Canyon, in Orange County, had spread to about 7,200 acres with 0 percent containment by Thursday at midday Pacific time, while other fires burned in Riverside County, requiring evacuations. With strong winds forecast to last throughout the day, fire danger remains “critical” to “extremely critical,” the two highest categories on the threat scale.
As of 10 a.m. Pacific, winds were gusting to 70 mph in the higher elevations near Malibu, with widespread wind gusts to 50 and 60 mph at lower elevations. Such winds can make fighting these fires nearly impossible, since they cause rapid fire spread and extreme fire behavior.
A moderate to strong Santa Ana wind event, featuring winds blowing from the land to the sea and extremely low relative humidity, is expected to continue through Friday in Los Angeles and Ventura counties.
The National Weather Service issued a rare “particularly dangerous situation” red-flag warning for the Santa Clarita Valley and the mountains in Los Angeles and Ventura counties, “Due to the combination of extremely dry vegetation, strong winds, and very dry air especially Thursday morning into Thursday afternoon.”
“If fire ignition occurs, conditions will be favorable for very rapid fire spread, long range spotting, and very extreme fire behavior which would threaten life and property,” forecasters warned. “The strong winds could also down trees and power lines.”
Red-flag warnings are in effect through Saturday farther south into San Diego County, where winds hit 90 mph in mountain locations Thursday morning.
Another Santa Ana wind event may affect Southern California early next week, too, the Weather Service said. In fact, there are signs of a strong offshore wind event with heightened fire danger in Northern California in the coming days, as well, which is extremely rare at this time of year. Normally, Northern California has received enough rain and mountain snow by this time of year to end the fire season, and would be moving into the heart of its rainy season.
“While it’s been done in the past, it’s not normal for us to be thinking about fire weather in December," said Brian Garcia, a meteorologist at the Weather Service’s forecast office in San Francisco.
But a vast area of high pressure over the West has been shunting storms well to the north of the state, causing it to fall deeper into a drought. Storms are being diverted so far to the north and west of California that rain and snow records were broken in Alaska.
The state is now in the midst of its worst wildfire season on record, with about 4.2 million acres burned, more than double the acreage in the previous record-breaking year. At least 10,488 structures have been destroyed and 31 people killed. Five of the top six largest fires on record in the state have occurred this season.
As California’s record-breaking 2020 fire season reaches into the winter months, it is overlapping not only with the windiest time of the year but also with a rapidly escalating wave of the coronavirus pandemic.
Southern Californians are therefore facing both evacuations and power shut-offs while managing concerns about the coronavirus.
With stay-at-home orders in place in Los Angeles County and tightening restrictions elsewhere, fear of contracting the virus could delay or discourage evacuations. To combat this, experts have noted that local emergency agencies should clearly communicate how people will be kept safe if and when they are told to leave home.
In lieu of public shelters during the pandemic, the Red Cross has established temporary evacuation points to arrange hotel rooms for wildfire evacuees in need of shelter.
But evacuations are not the only challenge during this latest virus surge. Power shut-offs, already disruptive, become life-threatening with thousands hospitalized and many on ventilators.
Reggie Kumar, a spokesman for Southern California Edison, the utility that serves Los Angeles and surrounding counties, said that hospitals typically have their own generators and are given advance notice about shut-off procedures and timing.
“We start notifying local emergency management officials three days prior to a Public Safety Power Shutoff event and work closely with them to determine if there is a need for a generator at a medical facility,” he said in an email.
By early morning Thursday, Southern California Edison had cut power to 32,395 customers, while San Diego Gas and Electric had cut power to 62,992 customers. These numbers could change significantly during the day Thursday, however.
Tom Rolinski, a fire meteorologist with Southern California Edison, said that a major concern for this event is the record dry vegetation in the region, even though December is outside of the normal high-risk fire season. “We are taking this very seriously,” he said.
No rain in sight as drought deepens
The forecast for the rest of the month is equally worrisome. Not only is there no real sign of rain, but there are additional Santa Ana winds on the horizon, including the one early next week.
“Every wind event is going to be very impactful for us, because fuels are very dry and very receptive to fire,” Rolinski said.
The 2020 wildfire season in California has been unrelenting because of record warmth, a deepening drought and an abundance of lightning strikes and strong offshore wind events. Santa Ana winds triggered major fires in Orange County in late October, forcing tens of thousands to evacuate on short notice. Now, vegetation is even drier. August, September and October ranked as the state’s hottest months since records began in 1895.
The extension of the dry season deeper into the fall is consistent with a delayed arrival of autumn rains over the past several years, an effect predicted to emerge in California because of human-caused climate change.
Recent studies have shown that warming and drying fall seasons are amplifying the fire threat, as the number of extreme fire weather days increases and very dry conditions extend later into the year. Again, this trend is in part the result of human-caused climate change and has also been seen in other parts of the world.
One study, for example, found that climate change has doubled the days during the fall with extreme wildfire conditions in parts of California since the 1980s.