After a rain-soaked, chilly week, temperatures as high as 80 and high surf are forecast

Southern California was beginning to dry out and warm up Friday, following days of persistent rain that flooded streets, triggered debris flows and sent boulders tumbling from hillsides across the region.

Thursday’s storm was the finale in a series of winter systems that dropped a significant amount of precipitation in Ventura, Los Angeles, Orange and Riverside counties. The storms drenched the San Gabriel Dam, north of Azusa, with 8.47 inches of precipitation. The Getty Center was hammered with about 6.21 inches of rain, while Malibu received 3.63 inches. In Orange County, Huntington Beach received more than 5 inches of rain, according to the National Weather Service.

The punch of moisture caused soil to slide from beneath a house in the Hollywood Hills and collapsed a staircase at a fourplex in Echo Park, which sent mud and concrete sliding onto parked cars. Los Angeles teachers who began their first strike in 30 years this week spent days picketing in the wet weather.

Clouds lingering in the region from the storm are expected to dissipate by Saturday, making way for sunny skies and temperatures in the 70s through much of the weekend, according to forecasters.

“We could be flirting with 80 degrees over the weekend in some areas,” said Adam Roser, a meteorologist with the National Weather Service in San Diego. “It should be quite nice.”

The weather service issued a high surf advisory through Friday night, warning that waves at west-facing beaches could reach up to 15 feet before subsiding Saturday.

Warm temperatures and large waves might send people running to the sand. Los Angeles County health officials, however, have warned beachgoers to think twice — or at least to pay attention to where they’re swimming — before they dip a toe in the salty water.

Officials said visitors should wait until Monday before entering any water near discharging storm drains, creeks and rivers, where bacteria and garbage often flow from city streets following large storms.

“Individuals who enter the water in these areas could become ill,” health officials wrote in a news release, adding that other areas of the beach are OK for swimmers.

hannah.fry@latimes.com

Twitter: @Hannahnfry