With parts of Los Angeles County still smoldering from wildfires, the expected rain this weekend would seem like a welcome relief. But how the rain falls could make the difference between a disaster respite or a disaster repeat.

At least 27 people have died in the Eaton and Palisades fires, the Los Angeles County Medical Examiner said Thursday evening. Seventeen of the deaths are from the Eaton Fire in Altadena and 10 from the Palisades Fire, according to the medical examiner.

"If fire ignition occurs, conditions are favorable for very rapid fire spread and extreme fire behavior," the NWS warns.

"A Red Flag Warning means that critical fire weather conditions are either occurring now, or will shortly," the NWS said.

The fires come as San Diego County mountains and valleys, along with other parts of Southern California, remain under a red flag warning.

Firefighters responded to a brush fire Wednesday north of Los Angeles on a day of red flag warnings for parts of Southern California.

CASTAIC, Calif. — Evacuation orders were lifted Thursday for tens of thousands as firefighters with air support slowed the spread of a huge wildfire churning through rugged mountains north of Los Angeles, but new blazes erupted in San Diego County, briefly triggering more evacuations.

The death toll from wildfires raging near Los Angeles has risen to 28, authorities said Tuesday, as new fires prompted evacuations near San Diego.

The National Weather Service said there is a 15-25% chance of thunderstorms across the region, which could bring periods of heavy rainfall that could overwhelm the burn-scar areas.

There is a 10% to 20% chance of flash flooding and landslides in some recently burned areas of Los Angeles County, forecasters say, including the Palisades and Eaton fire areas.

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The Los Angeles County Sheriff's Department said in an update Thursday that 18 people remain missing after the Southern California wildfires. Overall, authorities received a total of 43 missing persons reports related to the Eaton and Palisades fires. Of those, 12 were located safe.