California residents are being warned about excessive rainfall and strong winds on Tuesday, as the 12th atmospheric river event is set to impact the West and Southwest through Wednesday. 

The heaviest precipitation is expected in southern California, with the storm bringing more mountain snow. 

Isolated thunderstorms would develop in advance of the system, with urban and small stream flooding anticipated as well. 

A coastal flood advisory was underway for areas including Pismo Beach, Oceano, Port San Luis and Avila Beach. A flood advisory was also issued for much of Santa Barbara, Ventura, and Los Angeles counties until 7:30 a.m. 

NEW EVACUATIONS ORDERED NEAR CALIFORNIA TOWNS WHERE LEVEE BROKE 

The Hollywood sign past Lake Hollywood Park

The Hollywood sign past Lake Hollywood Park in Hollywood, California, on March 16, 2023. (Photographer: Alisha Jucevic/Bloomberg via Getty Images)

The National Weather Service's Los Angeles office also cautioned that there was an increased risk of flooding of roadways, and rock and mudslides. 

In the northern part of the state, wind and rain returned largely for the southern San Francisco Bay Area and Central Coast. 

A person walks past a flooded playground in Huntington Beach

A person walks past a flooded playground section of the park including the swings, bench and open play area at Edison Community Park as a series of storms is hitting the Southland, with rain expected to intensify Tuesday and Wednesday in Huntington Beach Monday, March 20, 2023.  ((Allen J. Schaben / Los Angeles Times via Getty Images))

A wind advisory was in effect for much of the Bay, with gusts of up to 60 mph possible. 

A high wind warning was in effect for Monterey and San Benito counties, the San Mateo Coast, the Santa Cruz Mountains and all of Santa Cruz County.

SOCAL MOUNTAIN COMMUNITIES STILL CLEARING SNOW FROM RARE BLIZZARD, OTHERS TRAPPED WEEKS LATER

"Prepare now for the potential of downed trees and power outages. Stay safe!" the agency's Bay Area office tweeted. 

Isolated thunderstorms were possible across portions of interior northern California, and a winter weather advisory was in effect above 4,000 feet through Wednesday morning. Total snow accumulations of 4-8 inches were projected, with up to 1 to 2 feet across higher elevations mainly south of Interstate 80. 

A snowblower removes snow in Tahoe

A snowblower removes snow in Tahoe City, Calif., Tuesday, March 14, 2023.  ((Stephen Lam/The San Francisco Chronicle via Getty Images))

"Be prepared for travel delays, possible chain controls, and reduced visibilities at times," the Sacramento office said. 

The UC Berkeley Central Sierra Snow Lab works in a snow pit

Working inside a nearly 18-foot-deep snow pit at the UC Berkeley Central Sierra Snow Lab, from left, Shaun Joseph, Claudia Norman, Helena Middleton take measurements of snow temperatures ahead of a weather storm on March 9, 2023, in Soda Springs, California. ((Karl Mondon/Bay Area News Group via AP))

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This season is the second snowiest in 77 years of record keeping, with more than 56.4 feet reported, according to the U.C. Berkeley Central Sierra Snow Lab. 

The Associated Press contributed to this report.