Lightning, hail, strong winds, flash flood warnings: SoCal has a serious case of fire weather

A man standing on a rooftop with a hose looks toward a massive cloud of smoke rising from a hillside.

By Ryan FonsecaStaff Writer

Sept. 9, 2024 6:30 AM PT

Good morning. It’s Monday, Sept. 9. Here’s what you need to know to start your day.

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Expect smoky air, thunderstorms and persistent heat as fire weather blankets SoCal

Southern California’s oppressive, record-breaking heat wave is awful enough on its own. But residents across swaths of the Southland now face a compounding threat: the massive Line fire in San Bernardino County, which is burning so hot that it has produced its own thunderstorms.

That’s creating even more risks for communities in and near the San Bernardino Mountains as regional officials warn of hazardous smoke, lightning strikes, hail, strong winds and potential flash floods.

“Los Angeles County and surrounding areas are under a red flag warning as temperatures are expected to reach more than 100 degrees in some parts,” my colleagues Teresa Watanabe and Colleen Shalby reported Sunday. “The combination of high heat and humidity will bring a chance of thunderstorms across the mountains of Los Angeles, San Bernardino and Ventura counties, and the Antelope and San Gabriel valleys.”

A car drives away from massive flames on a mountain road.

Here are the basics as of this morning:

More than 20,500 acres have burned
The fire is 3% contained
More than 36,000 homes and other structures are threatened
1,855 personnel are assigned to the fire
Three firefighters have been injured

Evacuation orders were in place for Running Springs and Arrowbear Lake, and evacuation warnings were issued Sunday for Lake Arrowhead, Cedar Glen, Crestline and Valley of Enchantment.

Fire officials said Sunday that their efforts had been challenged by erratic wind conditions, smoky air and limited resources.

Another major complication for firefighters and everyone else: pyrocumulonimbus clouds. The fire-triggered storm clouds produce lightning that grounds firefighting aircraft and could spark more blazes. And these fire clouds are forming more frequently, according to researchers.

“Hot and dry conditions mixed with thunderstorms are expected to challenge firefighters for the next few days,” they wrote on a public information webpage.

National Weather Service officials in San Diego said they had recorded more than 3,700 lightning strikes inside the clouds and over 280 ground strikes on Saturday alone.

A pyrocumulonimbus is the ultimate extreme pyrocumulus cloud.

“Pyrocumulus can cause additional complications when it comes to fighting the fire, creating gusty and sudden wind shifts, along with large amounts of [lightning] … and even rain,” officials noted on X this weekend.

That led the NWS to issue several flash flood warnings, including for some parts of Riverside, San Bernardino, Fontana and Rialto.

The Line fire reportedly started in the city of Highland in an area where tract housing meets the foothills of the San Bernardino Mountains.

Areas like that, known as the wildland-urban interface, are highly prone to wildfires. The cause of the blaze is under investigation, but the point of origin brought to mind a conversation I had last month with Seth Mitchell, a deputy forest fire management officer with the U.S. Forest Service.

Mitchell noted that, contrary to public perception, “the majority of wildfires start on private land and move into forested areas,” not the other way around.

Another wildfire sparked nearby Sunday

Firefighters faced a separate wildfire Sunday that broke out in the Angeles National Forest north of Glendora in L.A. County.

Dubbed the Bridge fire, it had burned 800 acres and was 0% contained as of Sunday evening.

Forest visitors were being evacuated from the area, and several roads were closed, including East Fork Road, State Route 39, Glendora Mountain Road and Glendora Ridge Road.

Forest officials said firefighters were performing an “aggressive attack with air and ground resources.”

California faces an explosive fire season after a mild couple of years

We’re at peak fire season in the West, and this year has been notably busy compared with the previous two seasons, which were tempered by back-to-back wet winters.

According to Cal Fire incident data, roughly 838,575 acres have burned so far this season. That’s more than in 2022 and 2023 combined.

Although fires are part of our forests’ natural ecosystem, human-caused climate change and roughly a century of flawed forest management have greatly increased the risks that wildland fires will explode into the massive infernos we’ve seen happen more frequently in recent years.

For updates Monday on the Line fire, Bridge fire and other fire weather hazards, you can follow the L.A. Times’ coverage. You can also check for updates from the National Weather Service in Los Angeles or San Diego, and from officials with the Angeles National Forest and San Bernardino National Forest.

Today’s top stories

Politics and power

State Sen. Marie Alvarado-Gil (R-Jackson) has been sued by her former chief of staff for alleged sexual harassment and retaliation.
Gov. Gavin Newsom heads to New York to raise money for Harris — then to Pennsylvania, where she’ll debate Trump.
A state Senate race between two Democrats in South L.A. is resurfacing allegations of racism and misconduct.
The LAPD is investigating a detective and union boss over allegations that his security company hires and underpays problem cops.

Climate and environment

With 25% of state land protected, California nears its “30x30” conservation goal.
The Inland Empire city of Jurupa Valley has approved a development project near Earth’s oldest living oak tree, to the dismay of some environmental groups.
Fifty-four more homes in Rancho Palos Verdes will be without power as the Portuguese Bend neighborhood continues to shift.

More big stories

California’s COVID summer may no longer be heating up — though officials caution the virus continues to circulate at levels high enough to pack a punch.
What to know about delta-8 and other common vape shop drugs.
Apology letters. Suspensions. After protest citations, students face campus consequences.
Compton’s own Kendrick Lamar will headline the 2025 Super Bowl halftime show.

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Commentary and opinions

Steve Lopez: They say Democrats are to blame for all of California’s problems. But the GOP is MIA.
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LZ Granderson: To win like the Rams, take big risks and learn from your losses.
Jackie Calmes: Listen up, Kamala — let Trump beat Trump.
Robin Abcarian: From “fridgescaping” to egg parties, we’ve become social-media-driven parodies of ourselves.
Guest opinion: When I talked about my pre-Roe abortion, other women’s stories poured out.

Today’s great read

A man in a wheelchair raises his arms in celebration on a basketball court.

Attendance and TV viewing figures from the Paris Paralympics have been encouraging. Could L.A. 2028 help take Paralympic sports to the next level? Athletes and officials shared their optimism with The Times’ David Wharton. “After decades of fighting for attention, they feel poised to emerge from the shadow of their older, more-glamorous sister,” David wrote.

How can we make this newsletter more useful? Send comments to essentialcalifornia@latimes.com.

For your downtime

Bburinkle chicken from BHC restaurant in Koreatown.

Going out

🍗 Snatch some of L.A.’s new food addiction: cheese-powder fried chicken.
🎭 Check out an updated “Cyrano de Bergerac” at the Pasadena Playhouse.

Staying in

😱 Curl up with a book of short stories from queen of horror Mariana Enríquez. Here’s a review of “A Sunny Place for Shady People.”
🧑‍🍳 Here’s a recipe for chocolate semifreddo.
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