The ninth storm hit California on Monday during a three-week period of extreme weather.
Heavy snow fell across the Sierra Nevada and the National Weather Service discouraged travel there.
Interstate 80, a key highway from the San Francisco Bay Area to Lake Tahoe ski resorts, reopened with chain requirements after periodic weekend closures because of whiteout conditions.
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"If you must travel, be prepared for dangerous travel conditions, significant travel delays and road closures," the weather service office in Sacramento said on Twitter.
The University of California Berkeley Central Sierra Snow Lab said it had recorded 49.6 inches (126 cm) of new snow since Friday.
A backcountry avalanche warning was issued for the central Sierra, including the greater Tahoe area.
A barrage of atmospheric river storms has dumped rain and snow on California since late December, cutting power to thousands, swamping roads, toppling trees, unleashing debris flows and triggering landslides.
Monday's storm was relatively weak compared to earlier storms, but flooding and mudslide risks remained because the state was so saturated, forecasters said.
President Joe Biden will travel to California's central coast on Thursday to visit areas that have been impacted by the extreme weather.
The White House said that the president would visit with first responders and state and local officials, survey recovery efforts and assess what additional federal support is needed.
Parts of Northern California could see more rain this week.
In San Francisco, 20.3 inches (51.5 cm) of rain has fallen at the city's airport since October 1, when California typically begins recording rainfall for the year.
The average for the "water year" is 19.6 inches (49.8 cm).
Across the bay in Berkeley, 10 homes were evacuated on Monday when a sodden hillside collapsed, sending mud onto properties. No injuries were reported.
In Sacramento Valley, residents of Wilton and surrounding communities were warned to prepare to leave if the Cosumnes River rose further.
In Monterey County, the swollen Salinas River swamped farmland over the weekend.
Governor Gavin Newsom signed an executive order to further bolster the state's emergency storm response and help communities that suffered damage.
President Joe Biden declared a major disaster in the state and ordered federal aid to supplement local recovery efforts.
At least 20 storm-related deaths have occurred, and a 5-year-old boy remained missing after being swept out of his mother's car by floodwaters in San Luis Obispo County.
Forecasters were keeping their eyes on a storm forming in the Pacific Ocean to see if it gains enough strength to become the state's tenth atmospheric river of the season.
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