Crews worked to dig roads, buildings and care home residents out of the mud across a wide swathe of south-western US desert as the first tropical storm to hit Southern California in 84 years headed north, prompting flood watches and warnings in half a dozen states.
The National Hurricane Centre in Miami said Tropical Storm Hilary had lost much of its force as it headed to the Rocky Mountains, but warned that “continued life-threatening and locally catastrophic flooding” is expected in parts of the region.
Forecasters said the threat of flooding in states further north on Monday was highest across much of south-eastern Oregon into the west-central mountains of Idaho, with potential thunderstorms and localised torrential rains on Tuesday.
As Hilary moved east into the neighbouring state of Nevada, flooding was reported, power was out and a boil-water order was issued for about 400 households in the Mount Charleston area, where the only road in and out was washed out. The area is about 40 miles (64km) west of Las Vegas.
Hilary first slammed into Mexico’s arid Baja California Peninsula as a hurricane, causing one death and widespread flooding before becoming a tropical storm.
So far, no deaths, serious injuries or extreme damage have been reported in California, though officials warned that risks remain, especially in the mountainous regions where the wet hillsides could unleash mudslides.
In one dramatic scene, rescue officials in the desert community of Cathedral City, near Palm Springs, drove a bulldozer through mud to a swamped care home and rescued 14 residents by scooping them up and carrying them to safety, Fire Chief Michael Contreras said.
“We were able to put the patients into the scoop. It’s not something that I’ve ever done in my 34 years as a firefighter, but disasters like this really cause us to have to look at those means of rescue that aren’t in the book and that we don’t do every day,” he said at a news conference.
It was one of 46 rescues the city performed between late Sunday night and Monday afternoon from mud and water up to 5ft (1.5m) deep.
Hilary is the latest potentially climate-related disaster to wreak havoc across the US, Canada and Mexico.
The Hawaiian island of Maui is still reeling from a blaze that killed more than 100 people, making it the deadliest US wildfire in more than a century. Firefighters in Canada are also battling their country’s worst blaze season on record.
Hot water and hot air were both crucial factors that enabled Hilary’s rapid growth – steering it on an unusual but not quite unprecedented path that dumped rain in some normally bone-dry places.
Scientists still do not know why some storms, like Hilary, get big and some stay small, said MIT hurricane scientist Kerry Emanuel.
“It’s quite unusual for an Eastern Pacific storm to be so large since they are usually small and stay deep in the tropics,” said University of Albany atmospheric scientist Kristen Corbosiero, an expert on Pacific hurricanes.
The wet weather might stave off wildfires for a few weeks in Southern California and in parts of the Sierra Nevada, but widespread rain is not expected in the most fire-prone areas, climate scientist Daniel Swain, from the University of California, Los Angeles, said in an online briefing on Monday.
Flooding and mudslides were reported across Southern California’s inland desert and mountain areas.
In the San Bernardino Mountains, crews worked to clear mud that blocked the homes of about 800 residents, Cal Fire Battalion Chief Alison Hesterly said.
In the Coachella Valley city of Desert Hot Springs, Steven Michael Chacon said the roads in the housing development where he and his husband live are impassable due to flooding and he is concerned emergency crews might not be able to reach people.
“Basically everybody’s got to stay put, there’s no way in or out,” he said.
Authorities said a woman was unaccounted for after witnesses saw her trailer swept away in a flash flood.
Hilary shattered daily rain records in San Diego and is believed to have dumped the equivalent of a full year’s worth on Death Valley National Park, forcing the park to be closed indefinitely and leaving about 400 people sheltering at Furnace Creek, Stovepipe Wells and Panamint Springs until roads can be made passable, park officials said.
“We basically blew all of our previous rainfall records out of the water,” National Weather Service meteorologist Elizabeth Adams in San Diego told the Associated Press.
A tropical storm last roared into California in September 1939, ripping apart railway tracks, tearing houses from their foundations and capsizing many boats. Nearly 100 people were killed on land and at sea.
Southern Texas is also preparing for the arrival of a separate tropical system that is expected to bring badly needed rain but also possible flooding.
The National Hurricane Centre said tropical storm conditions could arrive in coastal areas by early on Tuesday, including near the US-Mexico border, where some residents grabbed sandbags in preparation.
In the Caribbean, meanwhile, Tropical Storm Franklin churned near Haiti and the Dominican Republic on Monday, while Tropical Storm Harold is expected to bring heavy rain and high winds to south Texas early on Tuesday.
