Stormy weather

The water in Lake Arrowhead reflects a temporary calm before the weekend storm, which is expected to hit hardest in Southern California’s mountain areas.  (Richard Hartog / Los Angeles Times)

The sign says it all in Running Springs, where the arrival of heavy moisture in advance of rain reminds residents of the threat of mudslides and debris flows in areas devastated by October’s fires.  (Richard Hartog / Los Angeles Times)

Larry Burkhart of La Conchita fills sandbags that he will use to protect his home on Bakersfield Avenue, just below the unstable hillside in the seaside enclave north of Ventura. A mudslide there in January 2005 killed 10 residents.  (Stephen Osman / Los Angeles Times)

Alex Gunning, 15, braves the rain to continue practicing as a member of the Hart High School cross-country team in Valencia.  (Gary Friedman / Los Angeles Times)

Rain arrived in Southern California a bit later than forecast, and with it the potential for mudslides from hills exposed during the fall wildfires. The sign in Malibu reflected in these raindrops serves as a reminder: “Thanks to all those who fought the fires.”  (Spencer Weiner / Los Angeles Times)

Welcome to L.A.: Visitors from Canada -- Warren and Jennifer with their children, Janet and Victor -- race back to their car after checking out Will Rogers State Beach at the start of rain that finally arrived Friday.  (Ken Hively / Los Angeles Times)

Amid intermittent sprinkles, Vikki Paulisin, left, helps Jan Sukrau evacuate her horse Hope from the Step-N-Style Ranch in Modjeska Canyon in Orange County. County authorities have issued a mandatory evacuation of large animals from the mudslide-prone canyons where 15 homes were destroyed in the Santiago fire in October.  (Allen J. Schaben / Los Angeles Times)

Heavy moisture rolls into a residential area of Running Springs that was devastated in October’s wildfire. Mountain areas are expected to bear the brunt of the weekend storm, with forecasters predicting as much as 10 inches of rain.  (Richard Hartog / Los Angeles Times)

Paddle surfer Robert Franklin, 55, of Huntington Beach surveys the stormy skyline as he waits for a wave to roll in near the Newport Beach Pier. The coming storm was expected to bring high surf.  (Allen J. Schaben / Los Angeles Times)

A pedestrian struggles against the wind and past fallen tree branches in downtown Sacramento, where the storm had already arrived.  (Robert Durell / Los Angeles Times)

Cautionary tape surrounds the ruins of a home destroyed by fire in Malibu’s Corral Canyon area. Southland residents were bracing for mudslides that could be triggered by heavy rain.  (Spencer Weiner / Los Angeles Times)

Malibu resident Lenny Goldsmith, right, and Peter Demetriou fill sandbags outside the Carbon Canyon Road Fire Station.  (Spencer Weiner / Los Angeles Times)

Lisa Schlender and daughter Ava, 2, brave the rain at Cemetery Park in Ventura.  (Stephen Osman / Los Angeles Times)

Wolfgang Otto-Cramer, 3, plays in the surf as storm clouds pass overhead in Malibu late Thursday afternoon.  (Genaro Molina / Los Angeles Times)

Clouds are visible on the horizon between the burned branches of trees along Modjeska Grade Road in Orange County.  (Mark Boster / Los Angeles Times)

Scott Grevious, 33, of Huntington Beach watches as clouds roll across the ocean at dusk Thursday at the Huntington Beach Pier.  (Allen J. Schaben / Los Angeles Times)