Riverside County Under Flood Watch: National Weather Service

RIVERSIDE COUNTY, CA — While a flood advisory is in effect for portions of Riverside County Thursday afternoon, heavier nighttime rainfall will bring the potential of flooding across the region, according to the National Weather Service.

All of western Riverside County is under a flood watch beginning at 7 p.m. Thursday through 12 p.m. Christmas Eve. The Coachella Valley is also under a flood watch from 12 a.m. to 12 p.m. Friday.

Riverside County mountain communities are under a winter weather advisory from 12 a.m. to 12 p.m. Friday. The advisory includes the potential for strong winds.

The ongoing storm will be followed by a second wallop on Christmas Day, according to the NWS.

"An atmospheric river will impact Southern California [Thursday] evening through Friday morning, delivering heavy rainfall along with the potential of flash flooding to the region," according to the agency. "Showers will gradually decrease Friday afternoon through evening. The next round of more widespread precipitation will arrive Christmas Day and night with precipitation amounts significantly less, but lower snow levels."

Total rainfall amounts expected from the storms are 2 to 3 inches in western Riverside County, up to 7+ inches in the mountains, and 1 to 2 inches in the deserts.

The highest rain totals will most likely be on southwest-facing slopes of the San Bernardino County mountains, according to the NWS.

Snow levels are not expected to drop significantly, according to the agency. The Riverside County mountain communities of Idyllwild, Pine Cove, and Mountain Center, along with the San Jacinto Peak, all have snow in the forecast.

A rockslide triggered by rainfall disrupted travel on Highway 243 near Idyllwild Thursday.

Across the county, "temperatures will run significantly colder than normal through the end of the year," according to the NWS.

Winter storms are expected to deliver more rain and mountain snow next week.