California’s deadly wildfires may come to an end as a weekend storm soaks the dry terrain, but the storm brings a new risk of flash floods.

Flood watch alerts have been issued for areas in Los Angeles affected by recent wildfires, which erupted earlier this month amid hurricane-force winds after more than seven months without rain — a record for parts of southern California, NBC News reported on Saturday.

The 24-hour flood watch, starting at 4pm local time on Sunday, includes areas affected by the Palisades Fire, which has burned 23,448 acres and is 79 per cent contained, and the Eaton Fire, which has burned 14,021 acres and is 95pc contained.

The National Weather Service cited the risk of mudslides as the reason for the watches, which suggest that flooding conditions are favourable but not imminent. Federal forecasters estimate a 10 to 20pc likelihood of significant flooding and debris flow.

“While damaging debris flows are not the most likely outcome, there is still a lot of uncertainty with this storm,” the weather service office in Oxnard said, adding: “The threat is high enough to prepare for the worst-case scenario.”

The burn scar from September’s Bridge Fire in the Angeles National Forest above the San Gabriel Valley, along with the Hughes Fire area northwest of Los Angeles — which has burned 10,396 acres and was 79pc contained as of Friday — are also included in the scheduled flood watches.

Los Angeles County, along with cities like Los Angeles, Pasadena, and Baldwin Park, is providing sandbags to residents preparing for potential mudflows.

Rain could begin in Los Angeles County Saturday afternoon and intensify on Sunday with the possibility of “moderate to locally heavy rain and small hail or graupel,” according to the National Weather Service.

Forecasters expressed their prediction for a quarter-inch of rain in urban Los Angeles and up to an inch in San Diego, adding that Sunday could see heavier rain.

Winter storm warnings have been issued for the San Gabriel and San Bernardino mountain ranges, including communities like Wrightwood, Big Bear City, Big Bear Lake, Crestline, Running Springs, and Lake Arrowhead, due to expected snow. The 48-hour warnings will begin at 4pm local time on Sunday.

The weather service predicts up to 18 inches of snow could accumulate above 6,000 feet, with as much as 6 inches possible above 4,000 feet, from Saturday afternoon to Monday afternoon.