“On Tuesday, a broad plume of moisture will move over California,” the National Weather Service said in a statement, warning “anyone traveling on Christmas Eve or Christmas Day” in northern, central and southern parts of the state to “exercise extreme caution.”

Driven by an atmospheric river known as “the Pineapple Express,” which moves the heavy moisture from the tropical climes of Hawaii to rain on the West Coast, the storm is expected to dump rain and snow for several days.

Some Southern California communities could see up to 10 inches (25.4 centimeters) of rainfall, and “severe, widespread flash flooding is expected,” weather officials said.

In 2025, state officials say 8,019 wildfires killed 31 people and destroyed 525,223 acres (212,551 hectares) across California, with major fires in Los Angeles burning through residential neighborhoods including Pacific Palisades at the beginning of the year.

“Recent burn areas, including those impacted by the January wildfires, remain highly susceptible to mud and debris flows,” LA county officials said in a statement.

More than 100 homes were placed under evacuation orders Tuesday, Los Angeles County Sheriff Robert Luna said.

The storm was also expected to bring wind gusts of up to 55 mph (88 kph) across the state.

“The combination of increasingly saturated soil and the strong winds will bring the potential for widespread downed trees and power lines,” weather officials warned. “Lives and property are in great danger.”