Flames rushed across the outskirts of Vacaville, about halfway between San Francisco and Sacramento, taking out numerous homes and buildings and forcing hasty evacuations from swaths of the city of nearly 100,000. Some fled their homes on foot as the flames approached, others scrambled to save livestock in the surrounding farms and ranches, trying to shuttle sheep to safety and letting horses go free to save their lives.
Such evacuations were made even more complex because of the novel coronavirus, with some residents concerned that leaving their homes for shelters could compromise their health amid surging cases in California. Authorities urged residents to first and foremost get out of the path of the flames.
"Don't stay home, please follow evacuation instructions," said Denise Everhart, a division disaster executive at the American Red Cross. "[The virus] is not a reason to put your life at risk from wildfire."
Conditions in California almost could not be worse from a fire perspective, with extreme heat, dryness and wind forecast at least through Thursday. The temperature in Vacaville was expected to climb as high as 107 degrees on Wednesday, with low humidity and wind gusts, which can fan the flames.
Fire officials in California made an urgent plea Wednesday for help from the entire country, seeking hundreds of fire engines and more than 1,000 personnel to help fight the blazes. Cal Fire spokeswoman Lynnette Round said there are nearly 7,000 people already battling the wildfires as new fires continued to pop up.
Round said the state is facing a "fire siege from lightning" not seen in years: "Because this all happened at one time, it really stretches your resources, because you're trying to spread out your firefighters, and you can only — you have only a certain amount to go."
As of Wednesday afternoon, there had been no reported fatalities in the fires, but authorities said dozens of structures had been affected; Cal Fire has reported that 181 structures had been damaged or destroyed statewide during the 2020 fire season.
A burst of lightning strikes helped start the fires over the weekend, including a rare display in the San Francisco Bay area. Between midnight Saturday and midnight Wednesday, there were 20,203 cloud-to-ground strikes in California, according to Chris Vagasky of Vaisala, which operates the National Lightning Detection Network. The total number of lightning discharges was equivalent to 11 percent of California's average annual lightning activity.
Fueled by the heat, the round of summertime storms grew from a surge of moisture moving north from former Tropical Storm Fausto near the Baja Peninsula.
The episode has included the emergence of fire tornadoes between Reno, Nev., and Lake Tahoe. Thousands of structures were threatened by a fire in Santa Cruz and San Mateo counties, where evacuations were ordered for large areas, including the town of Boulder Creek. Areas around Napa Valley's wine country were evacuated as authorities begged people to heed their warnings to leave.
To the west of Vacaville in Healdsburg, the same complex of fires forced residents to evacuate starting Tuesday as Gov. Gavin Newsom (D) declared a state of emergency.
Helena Price Hambrecht and her 2-year-old daughter drove to San Francisco to check into a hotel while her husband stayed behind to protect the family's 200-acre farm. Situated at the end of a two-mile, one-way road, there's a danger of being trapped by fire, but the area has 68 acres of grapes that can act as a fire break.
"We have 14 chickens and two dogs, and if things get bad, we're just going to pack them all in the back of the truck and take them to the middle of the vines," said Price Hambrecht, who owns aperitif company Haus. "It's really disheartening that every year we have to leave and just cross our fingers that our house doesn't burn down. But it becomes this bizarre exercise in gratitude. Say we did lose the house — at least we were lucky enough to have time to prepare and not to burn in our sleep."
This is her fourth year facing fire season in the area as a full-time resident, a span that has included several devastating blazes.
Nine out of 10 of the largest California wildfires on record have occurred in the past two decades. The exact same is true for the top 10 most destructive fires in state history, a list that is led by the Camp Fire of 2018, in which 85 people died.
Scientists say that this is occurring because of better "fire weather," driven by the interlinked components of more heat and more dryness. These conditions turn trees and other vegetation into fuel for big and fast-moving blazes.
A 2013 study found that fully half of the increased area hit by fires in the Western United States, including California, could be attributed to human-caused climate change and its contribution to increasingly hot and dry weather.
People in the area still have fresh memories of the Camp Fire, which hit just a couple of hours away. Wildfire season has become as regular in California as hurricane season is in Florida. That has given many residents the advantage of better planning.
"Every year we learn something new when it comes to fires," said Kaitlyn Dart, a volunteer natural disaster responder in Solano County. "With a little more practice, we do learn how to make things work quicker."
The American Red Cross started rethinking its usual natural-disaster preparations in February, when the threat of a pandemic was becoming clearer.
Instead of sending people straight to shelters, the organization is working with local health and emergency departments to direct people to larger staging areas, like parking lots or fairgrounds, where they can determine the best place to send people. Workers are outfitted in protective gear and masks are provided to anyone who shows up. There are health screenings to determine who may have the coronavirus or have been exposed to it, or who is most at risk because of other health conditions.
"The biggest concern that the entire emergency management community, especially the Red Cross, had was that people wouldn't get themselves someplace safe," Everhart said.
The pandemic has been a challenge in other ways, as well. The Red Cross has had to recruit more volunteers this year, as many of its regular helpers have had to stay home to care for children out of school or elderly family members.
Knowles reported from San Jose; Freedman and Samenow reported from Washington. Chris Mooney in Washington contributed to this report.