The Christmas storm predicted to create widespread hazards, including flood risks, pushed into the Inland Empire Wednesday, generating moderate rainfall that hampered travel in some spots but did not immediately result in road closures or other obstructions.
The “Pineapple Express” atmospheric river triggered widespread precipitation in the predawn hours Wednesday, prompting the National Weather Service to post a Flash Flood Advisory for the western half of Riverside County until late in the afternoon.
“There may be minor flooding in low-lying poor drainage areas … and ponding of water in urban or other areas,” the NWS said in a statement.
Meantime, the agency issued a Flash Flood Watch until 10 p.m. Wednesday that encompassed the area stretching from the Orange County line to the west, through the San Gorgonio Pass to the Coachella Valley to the east.
Late Wednesday morning, the San Bernardino County Fire Department circulated images of significant flash flooding in the mountains and foothills around Wrightwood, with multiple homes damaged. However, there were no indications of similar immediate impacts around Idyllwild, Pine Cove or Mountain Center, which are also in the San Bernardino National Forest, south of Interstate 10.
The California Highway Patrol recorded numerous minor to moderate traffic accidents due to the rainstorm. A U.S. Postal Service vehicle overturned on wet streets in El Cerrito, but the mail carrier escaped with minor injuries.
Neither the CHP nor the Riverside County Transportation Department reported road closures or lane shutdowns on highways and freeways due to the weather, as of 1:45 p.m. Wednesday.
Cal Fire and the Riverside County Office of Emergency Services circulated messages via social media reminding inland residents to drive carefully amid downpours and avoid hazardous conditions wherever possible.
“Expect widespread moderate to heavy rainfall Christmas Eve with the potential for roadway flooding and localized flash flooding from the coast to deserts,” the NWS said. “Rapid rises in small streams and increased flow in main stem rivers expected.”
Meteorologists anticipated heavy rainfall from the atmospheric river spreading southward across the area for Wednesday morning, with the heavy rain continuing into the evening.
“Showers will continue on Thursday, with another round of more widespread showers for Thursday night into Friday,” according to the Weather Service.
The precipitation will likely be accompanied by gusty conditions, with winds up to 40 mph possible through valleys and passes.
Snow levels are expected to remain above 8,000 feet Wednesday morning, “increasing the potential for rock and mudslides along mountain highways, and debris flows in and below burn scars, especially in the San Bernardino County Mountains.”
The snow level could fall to about 7,000 feet by Thursday night, then down to 6,000 feet by late Friday.
Conditions should dry out over the weekend.