Tuesday, September 21, 2021

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Lightning-induced wildfires rage across California amid extreme heat, dryness


SAN FRANCISCO - Mired in a dry, sweltering heat that has baked the brush and timber into parched fuel, California is on fire again, with blazes threatening communities up and down the West Coast.

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Lightning-induced wildfires rage across California amid extreme heat, dryness

Tens of thousands of people evacuated their homes early Wednesday as wildfires raged out of control, this time after an unusual series of thunderstorms swept through the region with a barrage of more than 20,000 lightning strikes acting as lit matches to piles of kindling. Authorities said they were tracking and battling at least 92 known wildfires spanning more than 200,000 acres across California. Many of them are largely uncontained or not contained at all.

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 covid-19 outbreak, 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, Division Disaster Executive at the American Red Cross. "Covid 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. Vacaville was expected to reach as high as 107 degrees on Wednesday, with low humidity and gusty breezes, which can fan the flames.

Fire officials in California put out 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 lighting" 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.

An onslaught of lightning strikes helped start the fires over the weekend, with even a rare display in the San Francisco Bay area. Between midnight Saturday and midnight Wednesday, there were 20,203 cloud-to-ground lightning 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% of California's average annual lightning activity.

Fueled by the heat, the round of rare summertime storms grew from a surge of moisture ejecting north from former Tropical Storm Fausto near the Baja Penninsula.

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 the wine-growing Napa Valley region were evacuated as authorities begged people to heed their warnings to leave.

West of Vacaville in Healdsburg, the same complex of fires forced residents to evacuate starting Tuesday as California Gov. Gavin Newsom, D, declared a state of emergency.

Helena Price Hambrecht took her 2-year-old daughter and drove to San Francisco to stay in a hotel while her husband remained to protect the family's 200-acre farm. Located 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 amid hot and dry weather.

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 deadly Camp Fire of 2018, in which 85 people perished.

Scientists say that this is occurring because of better "fire weather," driven by two chief, interlinked components: more heat, and more dryness. These conditions turn trees and plants into fuels for raging, and fast moving, blazes.

A 2013 study found that fully half of the increased area burned 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 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 covid or have been exposed to it, or who is most at risk because of preexisting 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 volunteers have to stay home to care for children out of school or elderly family members.

Published : August 20, 2020

By : The Washington Post · Heather Kelly, Andrew Freedman, Jason Samenow, Hannah Knowles · NATIONAL, SCIENCE-ENVIRONMENT