Image source, Shutterstock

A storm like this hasn't been seen in southern California since 1939.

Here's a recap of what's been happening:

• Tropical Storm Hilary has been downgraded to a post-tropical cyclone as it heads north into Nevada
• Hilary was previously a category four hurricane and initially made landfall on the northern Baja California Peninsula on Sunday
• Twenty-six million people have been under flood warnings in California and Palm Springs has experienced its heaviest hour of rain ever recorded, California Governor Gavin Newsom has said
• Thousands of people across southern California are still without power and 911 lines have been down in Palm Springs
• A state of emergency has been declared by California's governor and President Joe Biden has ordered in federal aid
• Another natural disaster - a magnitude 5.1 earthquake - also shook parts of California earlier as people sheltered from Hurricane Hilary

Image source, Getty Images

In California, enormous sand banks have been assembled in front of many of the opulent beachfront properties to protect them from ocean surges.

But as we know, climate change is making extreme weather events like Storm Hilary increasingly likely, and that's something insurance providers are taking into close consideration.

At least three major insurers in California have stopped accepting new policies due to, as State Farm put it, “rapidly growing catastrophe exposure”.

The companies that continue to offer home insurance in places like California are increasing the cost of premiums.

It means the owners of these homes, some on the market right now costing upwards of $12 million (£9.4m) are forced to fork out for enormous premiums, or make the decision to relocate and try to sell their homes to someone who will.

• Read more about how insurers are responding to climate change here.

Image source, Getty Images

This is the first tropical storm to hit the south-west United States in over 80 years.

The severity and abnormality of the weather system - now a Post-Tropical Cyclone Hilary - is related to climate change, scientists argue.

“Over the last 40 years, climate change has made hurricanes more powerful, both in terms of wind speed and the amount of water they deliver as rain,” Kristy Dahl, principal climate scientist at the Union of Concerned Scientists, told the Los Angeles Times.

“To see a storm of this magnitude in this part of the world - and at this time of year - is highly unusual,” Dahl adds.

California’s Pacific Coast is usually protected from hurricanes and tropical storms due to a variety of factors including colder ocean temperatures.

This year, however, oceans hit their hottest ever recorded temperature.

And according to the National Oceanic and Atmospheric Administration, external: “This is why warming ocean temperatures matter; it’s like adding fuel to a fire and taking the world, literally, by storm.”

Thousands of people across southern California are still without power.

And in Palm Springs, one of the worst-hit spots, emergency services lines are suffering outages as a result of Storm Hilary tearing through the city.

"911 lines are currently down," a post from the city's official account , externalon X, formerly known as Twitter, says.

Residents are urged instead to call another number or text 911 for any police or fire-related matter. It said officials were working to fix the problem, but there was no estimated time for repair," it adds.

As people across Southern California sheltered from Hurricane Hilary; another natural disaster hit - a magnitude 5.1 earthquake.

Its epicentre was northwest of Los Angeles and #hurriquake was soon trending on social media.

It did not cause major damage, and the hurricane has also since been downgraded to a post-tropical cyclone.

Los Angeles Mayor Karen Bass said over 100 fire stations were checking buildings for damage.

Image source, .

• Read more in our news story here.

Peter Bowes
in Los Angeles

Image source, Reuters

This is a colossal storm, the like of which hasn't been seen in southern California since 1939.

Tropical Storm Hilary first made landfall on the Baja California peninsula of Mexico, where it caused extensive flooding.

This weather system is now moving through California, a state more used to drought than torrential rain during the summer.

The state's governor Gavin Newsom, after visiting the desert community of Palm Springs, said the town had received more rain over a 60-minute period than any time in its history.

The National Weather Service said there'd been life-threatening flooding along the Malibu coastline. But there are no reports of any casualties.

As the storm took hold, in a strange quirk of timing, a magnitude 5.1 earthquake rocked the city of Ojai, about 80 miles northwest of Los Angeles - there was some minor damage but no injuries.

Image source, Reuters

Juan Fejfar, whose home in California's Victorville is threatened by the rising floodwaters, has made the decision to board up his house and leave the area.

Fejfar and his mother are evacuating to his sister's house, nearby on higher ground.

He said it was too dangerous to stay at home, and had to make the call to ensure his survival: “If this road floods there is no way in or out," he told Reuters.

"It sucks to see it (the house) go, but lives can't be replaced, material objects can," he said.

Jacqueline Howard
Live reporter

Across California Storm Hilary brought severe flooding and destruction. We've researched pictures of some of the locations affected to provide a before-and-after view.

In Death Valley, floodwaters have filled the famously dry ridges of the landscape, transforming them into rapid rivers. The below pictures show how the arid terrain has been transformed.

Image source, Reuters

Image source, Google Earth

In Oak Glen, California, the storm caused severe mudflows that badly damaged roads.

Image source, Reuters

Image source, Google Earth

A major thoroughfare in California's Cathedral City has been closed due to flooding. Images of that same stretch of road dated November last year show it dry as a bone.

Image source, EPA

Image source, Google Earth

Image source, AFP

The Happiest Place on Earth became one of the wettest as then-Tropical Storm Hilary forced an early closure of the famed Disney amusement parks in Anaheim.

As rain pelted down on Sunday, all live entertainment shows were cancelled, including the fireworks, and the park closed entirely two hours earlier than usual.

Visitors brave enough to venture out were rewarded with speedy access to attractions.

Fan website Walt Disney World News Today said: "If you can deal with the drizzle, the wait times at Disneyland are non-existent."

Gareth Harvey
BBC Weather

Image source, Getty Images

Rainfall will also likely have impacts across parts of Oregon and Idaho with some areas in the states expected to see as much as five inches (127mm) of rain by Tuesday morning local time.

Flash flood warnings from the National Weather Service (NWS) remain in force across parts of southern California and into southern Nevada.

Half-a-year's rainfall came in just six hours at Palm Springs airport, according to the NWS.

California Governor Gavin Newsom said earlier that some areas of Palm Springs had seen more rain in an hour than in the city's entire history.

Isolated locations in the mountains to the west of Los Angeles, such as Upper Mission Creek, are reporting close to 13 inches of rainfall from Hilary.

Across the metropolitan area of Los Angeles itself, around 1-4 inches of rain has fallen in 24 hours. That compares to the Los Angeles city average annual rainfall of around 12 inches.

In Nevada, one area to the north west of Las Vegas has so far seen six inches of rainfall - approaching a 24-hour rain record for the state set in 2004.

Conditions should slowly improve over the coming 24 hours as rain pushes further north and eases in intensity from southern California and southern Nevada.

Storm Hilary moved north into the US only a few hours after making a landfall in Mexico.

Here are some pictures from Baja California peninsula in the north of Mexico, where officials warned for life-threatening flooding.

Image source, EPA-EFE/REX/Shutterstock

Image source, Reuters

Image source, Reuters

Image source, Reuters

What is now Post-Tropical Cyclone Hilary was previously a category four hurricane and initially made landfall on the northern Baja California Peninsula on Sunday.

It moved across the border from Mexico into southern California on Sunday afternoon, and continues to move northwards from California into Nevada whilst gradually weakening today.

The satellite image above shows the spread of Hilary earlier - with the storm system covering the states of California and Nevada - including the major cities of Los Angeles and Las Vegas.

Our colleagues at BBC Weather say Hilary will see sustained winds of 35mph (56kph) near the centre but is expected to continue weakening and should reduce later on Monday.

A further 50-100mm (2 to 4 inches) of rain could fall through the remainder of today with storm totals of as much as 300mm possible across parts of southern California and southern Nevada.

Image source, .

Next few hours will see heavy rainfallpublished at 10:24 British Summer Time 21 August 2023

10:24 BST 21 August 2023

Chris Fawkes
BBC Weather presenter

Image source, Reuters

As a tropical storm, Hilary moved northwards across California, near to the state’s Sierra Nevada mountains.

As it moves into Nevada, the storm is now a post-tropical cyclone, however this downgrade only refers to the strength of the winds – and it’s not the winds that are of particular concern.

Hilary will bring huge amounts of rain. More than a year’s worth of rain will fall for parts of the southwest.

This rain will hit a normally very arid part of the US with the ground unable to cope with the volume of water expected.

With up to 250mm (9.8 inches) forecast for parts of California and Nevada, this will result in severe flooding and mudslides – both bringing a significant risk to life.

Tropical Storm Hilary has just been downgraded to a "post-tropical cyclone" as it heads north into Nevada, BBC Weather's Chris Fawkes says.

Post-tropical cyclones can continue to carry heavy rains and high winds, the US National Weather Service says.

Image source, .

Image source, Getty Images

We're hearing more about the threat Storm Hilary poses from Jamie Rhome, deputy director of the US National Hurricane Center.

"This is unusual, but not unprecedented," he tells CBS News, noting that in 1997, Hurricane Nora brought storms, torrential rain and flooding just east of where Hillary is moving.

While the scale of Hilary is not out of the ordinary, "it's just not something that we would normally see every season or every 10 years," he adds.

Rhome says that much of the soil in Southern California is unable to handle much rainfall, especially when this much rain falls over such a short period of time.

"And so what happens when the rain falls on the ground rather than the ground soaking it off? It just runs horizontally, it creates these flash floods," he adds.

Image source, Getty Images

As California deals with its first tropical storm in decades, the National Weather Service in Los Angeles is issuing warnings for specific areas:

• Los Angeles, Glendale and Santa Clarita are expected to see heavy rains until 03:00 local time (11:00 BST)
• That applies to a region from Solromar on the seaside to Pomona in the east and Lancaster in the north
• There is a roadway hazard warning for Ventura County from previous rains
• It applies to Camarillo, Thousand Oaks, Simi Valley and Filmore
• There is another flash flood warning for Oxnard, Thousand Oaks and Simi Valley until 03:00 local time
• The water levels of San Diego River at Fashion Valley continues to rise. It was up to 8.95 feet at 22:15 local time, the highest-ever summertime level there

Image source, Reuters

Juan Fejfar lives out in Victorville, San Bernardino County, and spent Sunday with his mother evacuating their home.

As they nervously watched floodwaters inch closer to their home, they decided it was better to be safe than sorry and left.

“It sucks to see it go, but lives can't be replaced," he told Reuters.

"Material objects can. And it's better just to replace... fix whatever gets damaged than risking somebody drowning over something that's avoidable. So safety first."

Image source, Reuters

We've been hearing from CBS reporter Jason Allen who says the eye-catching storm is "absolutely unprecedented" as he explains it is rare for this immense amount of rain to make their way up as far north as California.

"I was at a station where they were filling up sandbags and one man remarks, 'I live in the desert. I'm not supposed to be doing this'," he tells CBS.

"Never before has there been tropical storm warnings on that Southern California coast."

He later tells BBC Radio 4's Today Programme there have been some evacuation orders - and while some people have been stacking sandbags around their homes, there are some who haven't been as convinced by all the warnings.

"A lot of people were just really curious about it more than anything else," he says.

"I would imagine the strength of it has surprised some people today as it did drop the rain which was promised."