SACRAMENTO, Calif. — The powerful storm that walloped Northern California over the weekend moved into Southern California on Monday, carrying with it the potential for localized flooding, strong winds and debris flows across the region.
A morning flood advisory was issued for southern and eastern San Luis Obispo County, where forecasters said rain could come pouring down at rates of up to 0.75 of an inch per hour.
Over the last 24 hours, some areas of the county — including Cal Poly San Luis Obispo and Rocky Butte — have recorded more than 5 inches of precipitation.
In Ventura County, officials warned that expected strong rains into the early afternoon could flood roadways and trigger debris flows in recent burn areas.
Downed power lines temporarily forced the California Highway Patrol to reroute traffic on Interstate 5 near Bakersfield shortly before 11 a.m. The thoroughfare fully reopened about half an hour later.
The storm also created some concern in Santa Barbara County, where a flash flood warning was issued near the burn scar of the Alisal fire. That expired shortly before 11:30 a.m.
The atmospheric river event will probably peak in Los Angeles around midday Monday and could dump up to an inch and a half of rain on downtown L.A. The Santa Lucia mountains in San Luis Obispo County could see as much as 5 inches, and roadway flooding and debris flows in recent burn areas are possible.
The system is “unusual for this time of year in terms of its strength,” said David Sweet, a meteorologist with the National Weather Service in Oxnard. “It’s a very, very powerful storm.”
The first major storm of the season has already shattered records.
Downtown Sacramento had an all-time-record 24-hour rainfall total of 5.44 inches, surpassing a mark set in 1880, officials announced early Monday. Rainfall totals that extreme would likely qualify as a “200-year storm,” which has about a 0.5% chance of happening in a given year, officials said.
Monday brought some relief to the capital city after a night of relentless rain toppled trees and flooded streets. Sunday night, many roads in the downtown area were inches-deep in water, backing up traffic and forcing cars to precariously cross water that reached halfway up their tires.
Creeks overflowed near the American River, where many homeless camps are located, prompting officials to open emergency shelters.
Blue Canyon in Placer County received 10.4 inches, breaking its previous record from 1964.
And in the San Francisco Bay Area, the 4.02 inches of rain that fell Sunday marked the wettest October day ever in downtown San Francisco, and the city’s fourth-wettest day in history.
About 125,000 residents across the state — from the Bay Area to Sacramento and Lake Tahoe and down to San Luis Obispo — were without power Monday morning, according to PG&E.
Power was out on the Bay Bridge around 7 a.m. — only hours after video circulated of big rigs on the Richmond-San Rafael Bridge being blown over by the storm.
In some areas, the rain turned to snow, creating dangerous conditions that prompted the closure of multiple major roads and passes across the state, according to the California Department of Transportation.
Along the Bay Area peninsula Monday morning, crews and homeowners were tending to downed branches in the streets, leaf-gummed gutters and toppled basketball hoops.
Large puddles formed at some roads and intersections. A 6-inch-deep pool of standing water made driving especially unnerving at the corner of El Camino Real and Valparaiso Avenue in Menlo Park.
Up in the Santa Cruz Mountains, however, first responders were feeling relieved.
“We dodged a bullet,” said Chief Mark Bingham of the Boulder Creek Fire Protection District. Evacuation orders had been in place over the weekend due to the risk of debris flows and flooding.
The system will lose some of its intensity as it moves south, but the threat of debris flows and damaging winds remains, Sweet said.
A wind advisory in San Luis Obispo County calls for gusts as strong as 50 mph through midday, with the potential for downed trees and power lines. Officials also issued a high surf warning until 9 p.m. Monday for the central coast of San Luis Obispo and Santa Barbara counties, as “powerful waves and strong rip currents will pose an exceptional risk of ocean drowning and damage to coastal structures.”
“Everyone should remain out of the water due to life-threatening surf conditions,” officials wrote in an advisory. “Stay off of jetties, piers and other waterside infrastructure.”
The Santa Barbara County Sheriff’s Office on Sunday ordered evacuations for residents near the Alisal fire burn scar, including those west of Las Flores Canyon, east of Mariposa Reina, south of West Camino Cielo and down to the ocean.
Urban and small stream advisories were also issued in the Alisal fire area through midday Monday, with roadway flooding and debris flows likely as heavier downpours move in. Those who have not evacuated were ordered to seek higher ground and shelter in place.
While not likely to report the same record-shattering totals as elsewhere, Southern California was still set for a decent soaking.
The brunt of the storm is expected to enter Orange County and the Inland Empire sometime in the midafternoon, before continuing its march southward toward San Diego, according to the National Weather Service.
“The evening commute may get a bit dicey, so please plan accordingly!” the agency’s San Diego office tweeted.
Cities closer to the coast could see anywhere from two-tenths to half an inch of rain through the evening, forecasters said. Higher parts of the San Gabriel and San Bernardino mountains could record rainfall totals of an inch or more.
The fall rains come as welcome relief after California reported its hottest summer on record and its driest water year in nearly a century, conditions that helped stoke a long and active wildfire season.
The storm is expected to cloak the Los Angeles area in cool weather, officials said, with highs expected in the mid-60s. Rain was already falling on San Luis Obispo County early Monday.
The torrential rainfall shut down at least one crucial highway as mud, rocks and unshackled debris flushed down denuded hillsides. Flash flood and excessive rain warnings blared across road signs and phone screens, with some officials declaring that for those in the Dixie fire burn area who had not yet evacuated, it could be too late.
“If you are near a burn scar, it may be too late to evacuate,” officials at the National Weather Service in Sacramento said on Twitter. “Do not attempt to cross a debris flow. Take shelter in the highest floor of your home.”
Multiple debris flows shut down Highway 70 between Jarbo Gap and Greenville, a historic mountainside community in Plumas County that had already lost so much to the Dixie fire. A photo circulating on social media showed a dramatic slide near the community of Tobin, where a huge pile of rock, trees and debris collapsed onto both lanes of the highway.
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(Times staff writers Alex Wigglesworth and Rosanna Xia contributed to this report.)
