Heavy rain, flash floods hit southern California

Los Angeles: Torrential rains unleashed flash floods and warnings of debris flow across southern California, particularly in fire scarred areas, with...

Los Angeles: Torrential rains unleashed flash floods and warnings of debris flow across southern California, particularly in fire-scarred areas, with further downpours forecast for Thursday as authorities declared a state of emergency in several counties.

Driven by an atmospheric river known as "the Pineapple Express," which moves heavy moisture from the tropical climes of Hawaii to the US West Coast, the storm was expected to deliver months' worth of rain over a few days.

Early Thursday, the National Weather Service (NWS) warned about the risk of excessive rainfall over parts of southern California, including in Los Angeles, the second-most populous city in the United States.

The NWS warned of a "broad plume of moisture" producing heavy rain in California on Christmas Day, adding there was a "moderate risk" of excessive rainfall over southern parts of the state.

"Numerous flash flooding events are possible. In addition, many streams may flood, potentially affecting larger rivers. The flooding may include debris flows in or near recently burned areas," the bulletin added, referring to areas affected by wildfires.