The US west coast is facing an atmospheric river event threatening flooding and power outages due to heavy rain and snow, with more than 20 million people in southern California under flood watches.
Evacuation warnings were issued by fire officials in the Pacific Palisades, Altadena and Pasadena areas, which were affected by the Palisades and Eaton fires in January.
“While we prepare for another storm headed towards LA, I want to urge Angelenos to stay vigilant, especially in burn scar areas,” the Los Angeles mayor, Karen Bass, said in a statement. “My number one job is to keep Angelenos safe, so please heed all evacuation warnings, stay vigilant and stay informed.”
Los Angeles mountain ranges are under a wind advisory until Thursday night. A flood advisory is in effect in Los Angeles until 6am PT, while a level 2 of 4 risk of flooding rainfall is in place from Santa Barbara to Los Angeles.
A special weather advisory was in effect for Los Angeles, Long Beach and east Los Angeles until 3.45am PT. In Orange county, a flash flood warning is in effect until 7.30am PT.
The National Weather Service said a tornado had moved through the Pico Rivera area early on Thursday morning. The agency said the tornado reached wind speeds of 85mph and traveled for about a mile. It caused exterior damage to homes and cars and snapped multiple trees.
The agency said that while tornadoes are not a frequent event in the Los Angeles area, they are not rare, either. In March of 2023, for example, a tornado injured one person and damaged 17 structures in Montebello.
State agencies have deployed more than 400 personnel to prepare to respond to the storm at the direction of the California governor, Gavin Newsom. “In Altadena and the Palisades, we’re continuing our months-long efforts to protect against potential debris flows,” Newsom stated on social media.
The California governor’s office of emergency services explained in areas burned by intense wildfires, the soil can develop a layer that repels water rather than absorb water, resulting in significantly less rain to produce a flash flood. The lack of vegetation and plants that hold soil in place also increases the risk of mudslides and debris flow, especially on and around steep terrain.
“Those living near recent brush fires should be aware of the extreme danger possible from debris flows,” a Los Angeles fire department spokesperson said in a statement.
“When rainstorms impact the Los Angeles area, storm drains, canyons, arroyos and other sloped or low-lying areas can quickly fill with fast-moving water and debris, creating a life-threatening danger.”
