California Fire Threat Mounts as Dry Winds Start to Rise

(Bloomberg) -- Firefighters across the U.S. West have used tools from shovels to airplanes to aluminum foil to tamp down wildfires so ferocious the smoke suffused the streets of Boston.

But just when early mountain snow and rain looked poised to relieve historic drought and heat, the atmosphere is about to bring another challenge: dry winds from the east that howl through canyons and valleys. Called Diablos in the north and Santa Anas in the south, these gusts have propelled some of California’s deadliest blazes and mark the start of the fire season’s most perilous phase.

This year, the stakes are even higher, thanks to a historic drought that's left much of the region brittle and dry. California’s danger zone is “from the border with Oregon to Mexico” -- in other words, the entire state, said Jon Heggie, spokesman for the state’s Department of Forestry and Fire Protection, known as Cal Fire.

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Engendered by climate change, wildfires have become so disastrous that they have sparked a major shift in forest management. California intends to cut, clear and burn 1 million acres of woodland a year by 2025 to head off disasters. And towns and cities are increasingly forced to confront an existential threat.

On Aug. 30, flames coming over California’s Sierra Nevada turned the air in South Lake Tahoe brown and orange, making breathing impossible. Mayor Tamara Wallace and her husband packed their car and fled, along with the rest of the town’s residents.  

“We never thought we would see our home again,” said Wallace, who weeks before had adopted a municipal evacuation plan along with the city council. “Never in a million years did I think we would be putting it into action.”  

More than 4,500 firefighters damped the Caldor fire, but not before more than 1,000 structures burned. And the burning season is far from over. 

Through Oct. 5, California’s 7,856 fires have charred just under 2.5 million acres, compared with more than 4 million acres for the same time period last year. The state has already spent an estimated $1.1 billion fighting blazes this fiscal year. Three people have died.

Blowing Fiercely

Across the West, the fire season has been relentless. The nation faced its highest risk level for a record 69 days, said Nick Nauslar, a meteorologist for the the National Interagency Fire Center in Boise, Idaho, which coordinates firefighting efforts. 

Nationally 46,508 fires have charred more than 5.9 million acres, which is about 1 million acres less than the 10-year average. But statistics don’t tell the whole story, Nauslar said. Past years have higher acreage because of massive blazes in Alaska, across the Great Plains and in the U.S. South. This year activity has been centered on the West alone.

“It indicated how busy we were out West this summer,” Nauslar said.

While the risks elsewhere have started to wane, California still remains in peril. Fires on windy days are worst, said Tom Larsen, a researcher for CoreLogic Inc., a risk-analysis company. 

“The big concern is that we are going to see more of those,” he said. An increase in the number of windy days or the duration of individual windstorms will become a problem. 

Cities at Risk

At this time of year, high pressure builds over Nevada and Utah and low pressure spreads over the Pacific just off California’s coastline. This draws the winds out of the desert West. The dry winds heat as they compress coming down mountainsides.

Half of California’s 20 most destructive fires happened in October, November and December, according to Cal Fire. That includes the Camp Fire in 2018, which killed a record 85 people.

That blaze signaled a new era for little towns tucked into California’s forests when it destroyed Paradise, said Wallace, the mayor of South Lake Tahoe, which is about 100 miles (160 kilometers) southeast.

“We have lived through fires before, but in the past it we have always just evacuated neighborhoods,” Wallace said. “Once the Paradise fire happened and the town of Paradise was obliterated, the conversation changed. It wasn’t a matter of evacuating neighborhoods after that.”  

PG&E Corp.,  California’s largest utility, is girding for the season. Its power lines have sparked some of the state’s deadliest blazes during autumn windstorms -- including the Camp Fire. In July, the utility discovered a tree had fallen on a line near the origin of the Dixie Fire, which exploded to become the second-largest in state history.

Defying Fire

At the company’s wildfire risk command center in San Ramon, executives gathered Tuesday for a weekly meeting about how to prevent equipment from starting more blazes.

Under a banner that read “Catastrophic Wildfires Shall Stop,” managers reviewed charts and graphs posted on white bulletin boards that showed progress in reducing fires, clearing trees and inspecting and fortifying poles and wires.

Chief Executive Officer Patricia Poppe said the company had made progress in tamping down accidents. “For the first time ever, we have confidence in our ignition reductions,” she said.

Meanwhile, the Caldor Fire, which chased out Wallace, isn’t quite extinguished. As of Oct. 7, it was 93% contained and there were still about 1,300 fire fighters battling it and repairing damaged areas, according to InciWeb, a wildfire tracking site. 

Heggie, of Cal Fire, said that “the new increase in fire behavior is not the new normal, it is the normal now.” 

“We are paying the price for a decade-long drought and the price is that we have be ready to evacuate at a moment’s notice. There is no room for error or hesitation.” 

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