Storm Hilary unleashes flash floods, mudslides and tornado warnings in California and Mexico

Storm Hilary has inundated streets across Mexico’s arid Baja California peninsula, swamping roads with deadly flood waters and downing trees.

The tropical storm dumped more than 15 centimetres of rain in some mountain communities and threatened more than an average year’s worth of rain in inland desert areas before moving over Southern California on Sunday evening (20 August).

It is the first storm of its kind to hit the state in 84 years - with record rains lashing Los Angeles and desert areas like Palm Springs and Death Valley. Around 26 million people are under flood warnings.

Forecasters said Storm Hilary has brought floods, mudslides, high winds, power outages and the potential for isolated tornadoes.

Hilary first made landfall along the Mexican coast on Sunday before moving through mudslide-prone Tijuana and then to San Diego. The storm is now expected to be heading north into inland desert areas.

On Sunday evening, the National Weather Service in Los Angeles warned of significant flooding risk throughout its populous mountain areas.

The agency posted on X, formerly known as Twitter: “PLEASE… STAY OFF THE ROADS.”

Mud and boulders spilled onto highways, water gushed onto roadways and tree branches fell in neighbourhoods from San Diego to Los Angeles.

Across the Coachella Valley dozens of cars were trapped in floodwaters while crews pumped flood waters out of the emergency room at Eisenhower Medical Centre in Rancho Mirage.

The National Weather Service said that "life-threatening flooding" was taking place along the Malibu coastline and in adjacent Ventura County communities.

Its warning about dangerous flooding applies to the coast from Point Dume to Point Mugu, and it includes the communities of Camarillo, Westlake Village, Somis and Spanish Hills, the weather service said.

At least 25,000 households across Los Angeles are out of power as the centre of the storm moved through the city on Sunday.

Hilary could hit other Western states of the US with a good chance of it becoming the wettest known tropical cyclone to douse Nevada, Oregon and Idaho.

It was expected to remain a tropical storm into central Nevada on Monday (21 August) before dissipating.

Hundreds of thousands of students in southern California will stay home from school on Monday. Students in San Bernardino, east of Los Angeles, are still expected to attend school but nearly every other district in southern California has cancelled classes.

Southern California also experienced an earthquake with a preliminary magnitude of 5.1 on Sunday. The earthquake hit near Ojai, about 80 miles northwest of downtown Los Angeles, according to the US Geological Survey.

According to a dispatcher with the Ventura County Sheriff’s Office there were no immediate reports of major damage or injury. But it was felt widely and was followed by smaller aftershocks.