Tropical storm Hilary has inundated streets across Mexico’s dry Baja California peninsula with deadly floodwaters, before moving over southern California, where it has swamped roads and downed trees.
On Sunday, concerns were raised that flash floods could strike in places as far north as the US state of Idaho, which rarely gets torrential rain.
Hilary, which forecasters say is the first tropical storm to hit southern California in 84 years, is bringing flash floods, mudslides, high winds, power outages and the potential for isolated tornadoes.
The storm made landfall along the Mexican coast in a sparsely populated area about 250 kilometres south of Ensenada on Sunday, then moved through mudslide-prone Tijuana, threatening the improvised homes that cling to hillsides just south of the US border.
At least 9 million people were under flash-flood watches and warnings as heavy rain fell across normally sunny southern California ahead of the brunt of the storm.
Desert areas were especially susceptible along with hillsides with wildfire burn scars, forecasters warned.
Mud and boulders spilled onto highways, water overwhelmed drainage systems and tree branches fell in neighbourhoods from San Diego to Los Angeles.
Dozens of cars were trapped in floodwaters in Palm Springs and surrounding desert communities across the Coachella Valley.
Crews pumped floodwaters out of the emergency room at Eisenhower Medical Center in Rancho Mirage.
The Los Angeles Unified School District, the United States’ second-largest school system, said all campuses would be closed on Monday.
“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.
San Diego schools postponed the first day of classes from Monday to Tuesday.
Southern California got another surprise in the afternoon as an earthquake with a preliminary magnitude of 5.1 hit near Ojai, about 130km north-west of downtown Los Angeles, according to the US Geological Survey.
It was felt widely and was followed by smaller aftershocks. There were no immediate reports of major damage or injury, according to a dispatcher with the Ventura County Sheriff’s Office.
Tropical storm Hilary could wallop other western US 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 as it moved into central Nevada early on Monday before dissipating.
By Sunday evening, Hilary had moved over San Diego and was headed north into inland desert areas. About midday, it had maximum sustained winds of 97 kilometres per hour.
National Hurricane Center director Michael Brennan said that while Hilary had weakened from a category four hurricane, it was the water, not the wind, that people should watch out for most.
He said some areas could get as much rain in hours as they typically got in a year.
“You do not want to be out driving around, trying to cross flooded roads on vehicle or on foot,” Mr Brennan said during a briefing from Miami.
“Rainfall flooding has been the biggest killer in tropical storms and hurricanes in the United States in the past 10 years, and you don’t want to become a statistic.”
Climate disasters across the US
Hilary is the latest major climate disaster to wreak havoc across the US, Canada and Mexico.
Hawaii’s island of Maui is still reeling from a blaze that killed more than 100 people and ravaged the historic town of Lahaina, making it the deadliest US wildfire in more than a century.
Mexican cities Ensenada and Tijuana have closed all of their beaches and opened half a dozen shelters at sports complexes and government offices.
One person drowned on Saturday in the Mexican town of Santa Rosalia after a vehicle was swept away in an overflowing stream.
Edith Aguilar Villavicencio, the mayor of Mulege township, said rescue workers saved four other people.
Mexican army troops fanned out across Mulege, where some of the worst damage occurred on Saturday on the eastern side of the Baja Peninsula.
Soldiers used bulldozers and dump trucks to help clear tonnes of boulders and earth clogging streets and roads that were turned into raging torrents a day earlier.
Power lines were toppled in many places, and emergency personnel were working to restore power and reach those cut off by the storm.
Mr Brennan said rainfall could reach between seven centimetres and 15 centimetres in many areas.
Forecasters warned it could dump up to 25cm — a year’s worth of rain — in some isolated areas.
California Governor Gavin Newsom has declared a state of emergency.
The Federal Emergency Management Agency said it had officials inside California’s emergency preparedness office and teams on stand-by with food, water and other help.
In coastal Carlsbad, just north of San Diego, 19-year-old Jack Johnson and his friends kept an eye on the huge waves, determined to surf them at some point on Sunday.
“It’s really choppy out there, not really surfable yet, but I think we can find a good break somewhere later,” Mr Johnson said.
“I can’t remember a storm like this.”
The weather service said tornadoes were possible in eastern San Diego County.
Authorities issued evacuation warnings on Saturday for Santa Catalina Island, urging residents and beachgoers to leave for the mainland and several mountain and foothill communities in San Bernardino County.
Orange County sent an alert out for anyone living in areas that had been affected by wildfires in the Santa Ana Mountains’ Silverado and Williams canyons.
Los Angeles authorities scrambled to get homeless people off the streets and into shelters.
Officials ordered all state beaches in San Diego and Orange counties to be closed.
Across the region, municipalities ran out of free sandbags and grocery shelves emptied as people stockpiled supplies.
California’s Joshua Tree National Park, Mojave National Preserve and Death Valley National Park were closed.
Death Valley’s Furnace Creek Visitor Center received more than 2.5cm of rain by 1:30pm with up to 7.6 cm more possible overnight.
“For comparison, Furnace Creek’s average annual rainfall is 5.6 centimetres,” the park said in a statement, calling the rainfall “unprecedented”.
To the north in Nevada, Governor Joe Lombardo declared a state of emergency and activated 100 National Guard troops to assist with problems from predicted flooding in western Clark and Nye counties and southern Esmeralda County.
In Arizona, wind gusts neared 97kph in Yuma County, where officials gave out thousands of sandbags.
“I urge everyone, everyone in the path of this storm to take precautions and listen to the guidance of state and local officials,” US President Joe Biden said.
Mr Biden said in a later statement he was being briefed on the storm and was prepared to provide federal assistance.
Meanwhile, one of several budding storm systems in the Atlantic Ocean became Tropical Storm Emily on Sunday, according to the National Hurricane Center.
It was far from land, moving west in the open ocean. Also, Tropical Storm Franklin formed in the eastern Caribbean. Tropical storm watches were issued for the southern coasts of Haiti and the Dominican Republic.
Source : ABC Net