By CHRISTOPHER WEBER
Associated Press

LOS ANGELES — Snow shut down a key interstate north of Los Angeles for hours on Monday while weekend downpours doused wildfires across Southern California in the first significant storm of the season for the region that had not seen rainfall for eight months.

As much as an inch of rain fell, posing another challenge as the wet weather loosened LA hillsides burned bare by the recent blaze near the Pacific Palisades, where crews working before dawn cleared inundated roadways including the famed Pacific Coast Highway.

Ash and mud flowed across streets in charred neighborhoods, and flood watches were in effect for the Palisades, Altadena and Castaic Lake areas.

“All these fresh burns are very susceptible to rapid runoff,” said Joe Sirard, a meteorologist for the National Weather Service’s office for Los Angeles.

In Malibu, four schools were closed Monday “due to dangerous road conditions,” the Santa Monica-Malibu Unified School District said in a statement.

In southern Kern County, snowy conditions late Sunday shut down the mountainous Tejon Pass section of Interstate 5, a key north-south artery for the state. It reopened Monday afternoon.

In Southern California, I-5 rises to more than 4,100 feet (1,250 meters) in Tejon Pass between Los Angeles and the San Joaquin Valley, making it susceptible to storm closures, especially on the steep section known as the Grapevine.

Mountains across San Bernardino and Riverside counties were under a winter storm warning Monday and were forecast to get about a foot (0.30 meters) of snow from the storm. Chains were required for some vehicles heading to ski resorts in the Big Bear Lake area northeast of Los Angeles because of icy roads.

Parts of San Diego County received more than an inch of rain, while other areas got less.

The rain began Saturday after months of dry and often gusty weather that created dangerous fire conditions.

Los Angeles County crews spent much of last week removing vegetation, shoring up slopes and reinforcing roads in areas devastated by the Palisades and Eaton fires, which reduced entire neighborhoods to rubble and ash after breaking out during powerful winds on Jan. 7.

The Palisades Fire, the largest of the blazes that destroyed thousands of homes and killed at least 11 people, reached 94% containment Monday. The Eaton Fire, which broke out near Altadena and has killed at least 16 people, was 98% contained.

The Hughes Fire, which ignited north of Los Angeles last week and caused evacuation orders or warnings for more than 50,000 people, was nearly contained.

Downpours in San Diego County, helped firefighters make significant progress against the smaller Border 2 Fire churning through a remote area of the Otay Mountain Wilderness near the U.S.-Mexico border.

Los Angeles city and county officials last week expedited cleanup efforts and other measures aimed at mitigating the environmental impacts of fire-related pollutants, and a White House statement on Friday said President Donald Trump has directed federal officials to help Southern California with clearing wildfire burn areas. Within five days of the order, the Federal Emergency Management Agency and other departments “shall develop and execute a plan to expedite the bulk removal of contaminated and general debris,” the statement said.

Officials cautioned that ash in recent burn zones was a toxic mix of incinerated cars, electronics, batteries, building materials, paints, furniture and other household items. It contains pesticides, asbestos, plastics and lead. Residents were urged to wear protective gear while cleaning up.

Concerns about post-fire debris flows have been especially high since 2018, when the town of Montecito, up the coast from Los Angeles, was ravaged by mudslides after a downpour hit mountain slopes charred by a huge wildfire. Hundreds of homes were damaged and 23 people died.

The rain ended a near-record streak of dry weather for Southern California. Most of Southern California is currently in “extreme drought” or “severe drought,” according to the U.S. Drought Monitor.