Forecasters said Hilary was the first tropical storm to hit Southern California in 84 years, bringing floods, mudslides, high winds, power outages and the potential for isolated tornadoes.
Tropical Storm Hilary inundated streets across Mexico’s arid Baja California Peninsula with deadly floodwaters before moving over Southern California, where it swamped roads and downed trees, as concerns mounted that flash floods could strike in places as far north as Idaho.
Forecasters said Hilary was the first tropical storm to hit Southern California in 84 years, bringing floods, mudslides, high winds, power outages and the potential for isolated tornadoes. The storm already dumped more than 15cm of rain in some mountain communities and threatened more than an average year's worth of rain in inland desert areas.
Hilary made landfall along the Mexican coast in a sparsely populated area about 250km south of Ensenada on Sunday, then moved through mudslide-prone Tijuana, threatening the improvised homes that cling to hillsides just south of the U.S. border. By Sunday evening, the storm had moved over San Diego and was headed north into inland desert areas.
As evening fell in California, the National Weather Service in Los Angeles warned of significant flooding risk throughout populous mountain areas along the coast northeast of Los Angeles.
“PLEASE ... STAY OFF THE ROADS,” the agency posted on X, formerly known as Twitter.
Mud and boulders spilled onto highways, water gushed onto roadways and tree branches fell in neighborhoods from San Diego to Los Angeles. Dozens of cars were trapped in floodwaters in typically hot and dry Palm Desert and surrounding communities across the the Coachella Valley. Crews pumped floodwaters out of the emergency room at Eisenhower Medical Center in Rancho Mirage.
Hilary could wallop other Western states with once-in-a-century rains, with a good chance of it becoming the wettest known tropical cyclone to douse Nevada, Oregon and Idaho. Hilary was expected to remain a tropical storm into central Nevada early Monday before dissipating.
The Los Angeles Unified School District, the nation's second largest school system, and said all campuses would be closed on Monday. San Diego schools postponed the first day of classes from Monday to Tuesday.
“There is no way we can compromise the safety of a single child or an employee, and our inability to survey buildings, our inability to determine access to schools makes it nearly impossible for us to open schools," Superintendent Alberto Carvalho said at a media briefing.
Southern California got another surprise in the afternoon as an earthquake with a preliminary magnitude of 5.1 hit near Ojai, about 80 miles (130 km) northwest of downtown Los Angeles, according to the U.S. Geological Survey. It was felt widely and was followed by smaller aftershocks. There were no immediate reports of major damage or injury, according to