After a brief lull in precipitation Tuesday, forecasters are warning of another “atmospheric river” expected to bring heavy rains and winds beginning Wednesday across an already-saturated California.
“It’s going to be a very impressive storm Wednesday and Thursday,” said Rich Thompson, a National Weather Service meteorologist in Oxnard. “An atmospheric river moving over the entire state of California.”
Days of significant rainfall, first from a massive New Year’s Eve system and then a smaller storm that moved in Monday night, have already soaked much of the state. Northern California fared the worst in the first storm, enduring substantial flooding, with thousands of Californians losing power in parts of Sacramento and San Francisco. More than 2,000 in Sacramento remained without power Tuesday morning, according to the Sacramento Municipal Utility District.
“We already have some ongoing flooding in the area … and we’re expecting more heavy rain,” said Scott Rowe, a meteorologist with the National Weather Service in Sacramento. The Sacramento Valley can expect an additional 2 to 3 inches of rain from Wednesday through Friday, while some areas in the foothills could see up to 6 inches — on top of the multiple inches of rain from days prior, he said. San Franciscans can expect to see at least 2 more inches of rain from the midweek storm.
A flood watch has been issued for much of Northern California beginning Wednesday and stretching through Thursday evening, with warnings of “excessive rainfall” that will likely cause even more flooding. Earlier rains already raised water levels on the Cosumnes River near Sacramento to record heights, breaching three levees and inundating nearby areas.
The looming storm is expected to also bring heavy winds to the state — up to 50 to 60 mph for the Sacramento Valley, Rowe said. He warned that people should expect widespread tree damage and possible power outages, in addition to more flooding.
Southern California also saw heavy rains but was spared the widespread disruptions, with the Los Angeles area recording 2 to 5 inches from the New Year’s storm, and then another quarter-inch late Monday from the smaller storm, according to the National Weather Service.
Thompson called Tuesday a “temporary drying out” for the L.A. area, before the rain picks back up again Tuesday evening, becoming heavier through Thursday. He said most of Los Angeles County could see 2 to 4 inches of rain during those days, with some areas getting up to 6 inches.
“We’re definitely looking at a lot of rainfall for this,” Thompson said. He warned that the next few days could also bring urban flooding, small streams overflowing and minor debris flows in burn scar areas of Southern California.
With high winds also expected, Thompson predicted that rush hour Thursday morning could be a nightmare, with minor flooding, the potential for fallen trees and other debris on the road and possible power outages.
Impactful weather continues…
Light precip. across northern Sacramento Valley today
Strong system arrives Wed-Thu with strong winds, heavy rain & mountain snow
Friday lingering showers & residual flooding impacts
Weekend & beyond…unsettled weather likely continues. #CAwx pic.twitter.com/insN99azAP
— NWS Sacramento (@NWSSacramento) January 3, 2023
Winds in Southern California are expected to reach 30 to 50 mph in the coasts and valleys, and up to 60 mph in the Antelope Valley and mountains.
Thompson also warned of hazardous coastal conditions during the storm, with high surf Thursday and Friday that could cause coastal flooding.
Times staff writer Brittny Mejia contributed to this report.