California authorities warn the latest wet winter storm could trigger mudslides in wildfire burn areas where thousands of residents are under evacuation orders.
Forecasters say up to 4 inches (10 centimeters) of rain is expected along the Central Coast, and the heaviest downpours are likely in the early hours of Wednesday.
The Santa Barbara County Sheriff's Office ordered 3,000 residents to evacuate hillside neighborhoods scarred by fires including parts of Montecito hit by a disastrous debris flow just over a year ago.
The National Weather Service has issued a flash-flood watch for all burn areas in Santa Barbara, Ventura and Los Angeles counties.
Heavy snow and high winds are predicted for the Sierra Nevada.
The wettest winter in years has nearly eliminated drought conditions in the state.