Daniel Swain for the Associated Press — Pacific storm that unleashed coastal flooding pushes across Southern California into Arizona 

UCLA climate scientist Daniel Swain discusses the recent Pacific storm for the Associated Press, sharing insights into its impact on Southern California and Arizona. The storm, which brought lightning and coastal flooding, moved eastward into Arizona, affecting holiday travel plans. Swain notes the storm’s extraordinary rainfall in coastal counties northwest of Los Angeles, particularly in Oxnard, where it exceeded average December rainfall. “In Oxnard, particularly, overnight there were downpours that preliminary data suggests were probably the heaviest downpours ever observed in that part of Southern California.”