Rain Forecast Helps California Firefighters But Adds Risk of Mudslides

November 20, 2018 Updated: November 20, 2018

California cities and towns devastated by wildfires recently are now facing increasing uncertainty as a couple of Pacific storm systems approach this week, bringing fears of mudslides.

According to the Weather Channel, two systems carried by the jet stream will land on the west coast on Wednesday and Thursday respectively. They are estimated to deliver at least an inch of rain or snow in total in much of northern California.

Fortunately, the coming rain is considered favorable for firefighting as the Camp Fire has been burning through Northern California since Nov. 8. The fire has claimed 79 people’s lives and left more than 15,000 buildings destroyed. The widespread rain could dampen the dry vegetation and further suppress the fire, which was 70% contained after charring 151,000 acres of land, according to Cal Fire.

In addition, the air quality affected by the massive wildfire could improve as the rain and wind washed away the smoke lingering in California.

However, the forecast also indicates the intensity of rain could reach 2 to 4 inches through Friday night in the coastal ranges and Sierra foothills, which raises the concern of ash flow and even possible mudslides.

“If there is heavy rain, there is the possibility of debris flows,” Eric Kurth, a meteorologist at the National Weather Service’s Sacramento office, said late Saturday morning. “There is some potential for ash flow with significant rain on the newly burned areas, which means the light ash on the surface will get washed downslope.”

Though the rain systems are not posing an intense flooding threat, the rain and following possible mudslide could add difficulties in searching for the remaining victims.

The Butte County Sheriff’s Office last Sunday updated the missing persons list and removed about 300 names off the list, bringing the total number down to 993. About 400 search and rescue crews and volunteers were sent to the charred land last Sunday to find fragments of bone before rains could wash them away or turn everything into a thick paste, reported CBS.

In Southern California, the recent burn areas are facing a similar situation. The National Weather Service (NWS) said the region is expecting a quarter-inch to one inch of rain for most of the area and heavier rain for the coastal slopes and foothills area.

As a result, mudslides and rockslides were considered a possibility at all areas affected by the Woolsey and Hill fires, especially along Highway 1 and the canyon roads. In addition, major traffic delay warnings were also issued by the authority.

The Woolsey Fire that ignited on Nov. 8 has burned about 97,000 acres in Los Angeles and Ventura counties with 96 percent containment. The Hill Fire is fully contained after destroying about 4,500 acres of land.

To help residents protect their homes from possible mudflows, several fire stations in Ventura County are offering sandbags and sand in the wake of coming rain.

In January 2018, a series of deadly mudslides took place in Santa Barbara County one month after the Thomas Fire raged through the area. The mudflows killed 21 people and leveled more than a hundred homes. According to the state’s insurance commissioner, the mudslides caused more than $421 million in insurance losses.