After a day of relative calm, Northern California is bracing for another windstorm that could complicate efforts to contain the immense Kincade Fire, which has forced nearly 200,000 wine country residents to evacuate and is moving steadily toward the city of Santa Rosa.
The National Weather Service issued a wind advisory for parts of Sonoma and Napa counties between noon Tuesday and 11 a.m. Wednesday, with the strongest gusts expected overnight. The increased wind will create “rapid fire growth potential,” the Weather Service said.
At the same time, conditions in Southern California, where the Getty Fire on Monday scorched the western edge of Los Angeles, are expected to be even more dangerous: The Storm Prediction Center warned of “extremely critical fire weather” beginning late Tuesday, when powerful Santa Ana winds are expected to whip across the region. A “long duration of low humidity and dry vegetation will make this a very critical event!” National Weather Service Los Angeles said.
The dire weather warnings came just days after Gov. Gavin Newsom, D, declared a statewide emergency over wildfires — and amid an unprecedented wave of blackouts ordered by Pacific Gas & Electric, which has shut power to millions of customers in an effort to curb fire risk. Newsom has called the shut-offs “unacceptable.”
The state’s largest utility has told regulators that a jumper on one of its transmission towers broke close to where the Kincade Fire started, near Geyserville. The cause of the fire, which has been burning since Wednesday, is under investigation as 4,548 firefighters battle the blaze.
Monday was a relatively quiet night on the front lines of the Kincade Fire. On Tuesday, the California Department of Forestry and Fire Protection said that the blaze barely grew overnight, though at 75,415 acres — an area more than twice the size of San Francisco — it is already California’s biggest fire of the year. The fire is now 15 percent contained, and officials said they expected it to burn until at least Nov. 7.
Firefighters got a brief reprieve Monday when gusts died down, but they struggled to keep pace with the expanding blaze as winds changed direction, officials said. Even as officials lifted mandatory evacuation orders for parts of the county along the Pacific coast, they issued new evacuation warnings for a part of Lake County as the flames threatened to lurch eastward.
At least 124 structures have been destroyed in the fire, but only one injury has been reported and no deaths have been attributed to the blaze, which is burning in the same region where 22 people were killed in the 2017 Tubbs Fire. Evacuations have largely gone smoothly as the nation’s most populous state adapts to increasing wildfires that many officials link to climate change.
Emergency responders on the other end of the state are trying to beat back a fast-moving brush fire that has consumed about 618 acres on the western edge of Los Angeles and forced the evacuation of more than 10,000 homes and businesses. Mayor Eric Garcetti, D, said Monday evening that the Getty Fire was 5 percent contained and had not grown since midday. At least eight homes have been destroyed in the blaze, and six others have been damaged, officials said.
The Getty and Kincade fires have been sparked by hurricane-like winds that for three years have caused fiery infernos to break out across the Golden State, which is coming to accept the blazes as the new normal. The gusts are known as Diablo winds in the San Francisco Bay area and Santa Ana winds in Southern California.
Red flag warnings
Red flag warnings are up for the San Francisco Bay area and much of north-central California. The most volatile conditions in the vicinity of the Kincade Fire are forecast to occur from Tuesday through Wednesday afternoon, when winds in higher elevations may reach 65 mph.
Offshore winds are also anticipated for lower elevations, which will lead to extremely dry air that is conducive for rapidly spreading wildfires. The ongoing offshore wind event, which is powered by the difference in air pressure between the Great Basin region and coastal California, is not anticipated to bring winds as high as the event over the weekend when the blaze began.
Northern California faced a blast of wind Wednesday and Thursday, and again over the weekend, when it was whipped with hurricane-force gusts. The coming surge this week, on Tuesday and Wednesday, is expected to be the third windstorm in quick succession.
The repeated high wind events are resulting in dry vegetation that will burn easily if any new fires ignite. In fact, forecasters in San Francisco said they have never before seen three red flag warning events in a seven-day period.
“I’ve been in this business for 28 years. I’ve never seen anything like this,” said Steve Anderson, a meteorologist at the National Weather Service’s forecast office serving the San Francisco Bay area.
Residents of Southern California, particularly from Los Angeles and Ventura counties south to San Diego, are gearing up for what could be a record-setting Santa Ana wind event beginning around midnight Tuesday night and continuing through Thursday. A red flag warning has been hoisted for the metro L.A. area, where winds could gust as high as 80 mph in higher elevations and canyons and reach 70 mph in valley locations.
In an ominous sign, the National Weather Service said early Tuesday that the upcoming event promises to be a “high end dangerous event.” One indicator of this is that the air pressure gradient, which controls how strong the winds will be, is forecast to be at record-high levels for late October and early November. In general, the greater the pressure gradient, the stronger the winds, since air flows from high to low pressure.
Given that there have been many Santa Ana wind events during this period, a record-setting event would be particularly dangerous and could cause significant damage of in the form of downed trees and power lines and minor structural damage, according to the NWS. Any fires that occur during this period could be nearly impossible to control.