Rainfall throughout the day was expected to be “heavy to excessive” across the state, especially in southern California, as winds gusts were clocked at more than 40 miles (64 km) an hour in many places, the National Weather Service said.
The high winds wreaked havoc on the power grid, knocking out electricity to tens of thousands of Californians. As many as 220,000 homes and businesses were without electricity on Tuesday morning, according to data from Poweroutage.us.
The treacherous weather, expected to dump as much as 7 inches (18 cm) of rain in some parts by Wednesday, could produce widespread flooding, rapid water rises, mudslides and landslides, especially in areas where the ground has been saturated from previous heavy rainfall, the service warned.
Experts say the growing frequency and intensity of such storms, interspersed with extreme dry spells, are symptoms of climate change, posing greater challenges to managing California’s precious water supplies while minimizing risks of floods, mudslides and wildfires.
The weather service’s forecast comes after the evacuation of some 25,000 people, including the entire picturesque town Montecito, an affluent coastal enclave 90 miles northwest of Los Angeles, and nearby areas of the Santa Barbara coast, due to heightened flood and mudslide risks.
The Montecito evacuation zone was among 17 California regions where authorities worry the ongoing torrential downpours could unleash lethal cascades of mud, boulders and other debris in hillsides stripped bare of vegetation by past wildfires.
The torrential rains, along with heavy snow in mountain areas, are the product of yet another “atmospheric river” of dense moisture funneled into California from the tropical Pacific, powered by sprawling low-pressure systems churning offshore.
At least a dozen fatalities have been attributed to several back-to-back storms that have lashed California since December 26, including a toddler killed when a redwood tree was blown over his family’s trailer home last week.