A downpour has turned the ash from a devastating California wildfire into paste, making it difficult for volunteers to find fragments of bone and forcing them to stop their search for human remains.

Craig Covey, leading a search team from southern California’s Orange County, said those looking through the devastation in Paradise and two nearby communities were not told to stop, but that he chose to take a break until the rain cleared.

Heavy rain and strong winds were knocking over trees, raising the risk they could fall on searchers, he said.

“It’s just not worth it – we’re not saving lives right now, we’re recovering lives,” Covey added.

California Wildfires High winds and heavy rains are temporarily halting the work of some search teams (Kathleen Ronayne/AP)

The nation’s deadliest wildfire in the past century has killed at least 84 people, and more than 560 are still unaccounted for.

Despite the bad weather, more than 800 volunteers searched for human remains on Thanksgiving and again on Friday, two weeks after flames swept through the Sierra Nevada foothills, authorities said.

Covey’s team of about 30 had been working for several hours Friday morning before stopping and returning to a staging area with hot coffee and food under two blue tents. An electric heater provided warmth.

While the rain is making everybody colder and wetter, they are keeping the mission in mind, search volunteer Chris Stevens said, standing under an awning as the team waited out a stretch of heavy rain.

“Everyone here is super committed to helping the folks here,” he said.

Two days of showers have complicated the search but also helped virtually extinguish the blaze, said Josh Bischof, operations chief for the California Department of Forestry and Fire Protection.

Once the rain clears, state officials will be able to determine if the blaze is fully out, he said.

The Camp fire ignited on November 8 and has destroyed nearly 19,000 buildings, most of them homes, more than the worst eight fires in California’s history combined, the agency said, with thousands of people displaced.

The volunteers interrupted by rain on Friday found other ways to help.

Covey and several team members took two big brown bags full of lunch to 64-year-old Stewart Nugent, who stayed in his home and fought off flames with a garden house, a sprinkler and a shovel. He has been there for two weeks with his cat, Larry.

The first winter storm to hit California has dropped two to four inches of rain over the burn area since it began Wednesday, said Craig Shoemaker with the National Weather Service in Sacramento.

California WildfiresStewart Nugent stayed in his home and fought off the flames (Kathleen Ronayne/AP)

The weather service issued a warning for possible flash flooding and debris flows from areas scarred by major fires in northern California, including the areas burned in Paradise.

Shoemaker said the rain there has been steady, and forecasters expect the heaviest showers in the afternoon.

“So far we’ve been seeing about a quarter-inch of rain falling per hour,” he said. “We need to see an inch of rain per hour before it could cause problems.”

He said the rain was expected to subside by midnight, followed by light showers Saturday.

In southern California, more residents were allowed to return to areas that were evacuated because of the 151-square-mile Woolsey fire as crews worked to repair power, telephone and gas utilities.

About 1,100 residents were still under evacuation orders in Malibu and unincorporated areas of Los Angeles County, down from 250,000 at the height of the fire.

The fire erupted just west of Los Angeles amid strong winds on November 8 and burned through suburban communities and wilderness parklands to the sea, leaving vast areas of blackened earth and many homes in ashes.

Officials say three people were found dead and 1,643 structures, most of them homes, were destroyed.