PALM SPRINGS, Calif. − The remnants of Hurricane Hilary lashed the U.S. Southwest from the mountains and desert to the Pacific Ocean beaches Monday, the storm downgraded to a post-tropical cyclone after triggering mudslides, flooding and water rescues across Southern California.

Rain and debris washed out roadways and left vehicles stranded in standing water. Parts of Los Angeles County had almost 7 inches of rain, and Beverly Hills had almost 5 inches by early Monday.

More than 100 miles to the east in Riverside County, a foot of rain fell on Mount San Jacinto. The nearby Coachella Valley was hard-hit, and Palm Springs police at one point Sunday said 911 lines were down so residents had to text 911 or reach out to the nearest police or fire station. Crews in Rancho Mirage pumped floodwaters out of the Eisenhower Medical Center. Officials in Palm Desert urged residents to stay home or proceed with caution while workers cleaned up downed trees and mitigated flooding.

“This storm has been unlike anything our community has faced before," officials said in a Facebook post. "Not everything is a quick fix, but our team is doing our best to have Palm Desert up and running."

Schools, businesses and offices closed across the region as the storm remained capable of "life-threatening and locally catastrophic flooding" for parts of the U.S. Southwest, the National Weather Service warned.

Hilary could produce another 2 to 4 inches of rain in many areas, and isolated communities across portions of Southern California and Southern Nevada could see up to 12 inches through Monday, the weather service said. As the storm rolls north, parts of Oregon and Idaho could get hit with up to 5 inches of rain through Tuesdaymorning, resulting in some "significant" flash flooding, the weather service said.

But Southern California was not free of Hilary's wrath.

"Across interior Southern California, road and rail line closures due to major flooding, washouts and mudslides are likely, putting a significant strain on infrastructure," said Dan DePodwin, AccuWeather director of forecasting operations.

Tropical Storm Hilary updates:Storm drenches Southern California, prompting floods, rescues

Developments:

∎ In San Diego, rescue teams pulled 13 people from knee-deep water in a homeless encampment along the rising San Diego River. San Diego Mayor Todd Gloria declared a state of emergency ahead of the 1.82 inches of rain the city received Sunday − the most of any August day on record.

∎ Preliminary 36-hour rainfall from southern Nevada shows that Bristlecone, west of Las Vegas, was doused with 6 inches, breaking the rainfall record for a tropical cyclone or remnant for the state.

∎ South-central Arizona could see strong, severe thunderstorms Monday, the weather service said.

Hilary tracker:Hilary tracker: Follow storm's path as post-tropical cyclone moves into Nevada

Emergency incidents doubled in Los Angeles

In Los Angeles, Fire Chief Kristin Crowley said Monday that her department had dealt with more than 1,800 emergency incidents over a 24-hour period, more than double the average number. Mayor Karen Bass said there were no reports of deaths or injuries and that damage appeared to be relatively minor. Crews were out cleaning up debris and returning power in areas that went dark.

Most city workers were working remotely Monday but were expected to return to offices Tuesday, she said.

"Our commitment to you is that we will approach our recovery with the same intensity as we approached our preparation," Bass said.

Palm Springs could get a year's worth of rain in 2 days

Palm Springs had been deluged by more than 3 inches of rain by Monday morning. Almost an inch fell in one hour Sunday afternoon in a city that typically picks up less than half an inch all summer, AccuWeather said. Palm Springs averages less than 6 inches of rain a year and could get that in 48 hours, AccuWeather said.

The city of Palm Springs declared an emergency "due to unprecedented rainfall in flooding of local roadways and at least one swift water rescue." 

Some residents dealt with earthquake during storm

An earthquake with a preliminary magnitude of 5.1 jolted parts of Southern California on Sunday in the midst od the storm, according to the U.S. Geological Survey. The earthquake, which struck at 2:40 p.m. local time, was centered about four miles southeast of Ojai. The Ventura County Sheriff's Office said no substantial issues, such as injuries and major damages, were immediately reported.

There is no apparent cause-and-effect between storms and earthquakes, the U.S. Geological Survey says on its website.

Lake Mead closed since Friday

The Lake Meade National Recreation Area remained closed Monday "for the purposes of maintaining public healthand safety" after being damaged by Hilary. The lake, the nation's largest man-made reservoir, is on the Colorado River in Nevada and Arizona, about 25 miles from the Las Vegas Strip.

The Park Service said the recreation area had experienced multiple power and utility outages and dock damage that makes access difficult for emergency response boats. Multiple park areas rely on one road access with low water crossings that likely will be be washed out, disconnecting entire communities from service and rescue, the Park Service said.

Saddled by years of drought, increasing demands for water and climate change, the lake level reached historic lows last year and the remains of several bodies were found. Last week, however, the Bureau of Reclamation said investments in system conservation and improved hydrology have led to "significant improvements."

Hilary was first tropical storm to hit the region in 26 years

The storm formed off the west coast of Mexico on Aug. 16, strengthening to a Category 4 hurricane before making landfall Sunday as a tropical storm along Mexico’s Baja California Peninsula. The storm moved through Tijuana before it became the first tropical storm to cross into California from Mexico since Nora in 1997, the weather service office in San Diego said Sunday.

If Hilary had come in off the ocean in a landfall in California, it would have been the first tropical storm to do so since 1939.

The storm was forecast to dissipate late Monday.

Hilary in photos:Hilary in photos: See flooding, damage in Southern California after storm moves through

Tropical Storm Franklin threatens Puerto Rico; Gert 'unraveling'

Tropical Storm Franklin was less than 250 miles south of the Dominican Republic early Monday and tropical storm watches and warnings were issued across much of the island shared with Haiti. Franklin is expected to produce rainfall amounts of up to 6 inches, across Puerto Rico through the middle of the week.

What began as a large area of low pressure off the Cabo Verde Islands has become well-defined enough to earn a name and designation. Tropical Storm Emily, with maximum sustained winds of 40 mph, was heading west-northwest in the Atlantic Ocean at nearly 10 mph Sunday.  However, Emily was expected to weaken and lose its status as a tropical storm in the coming days.

Tropical Storm Gert was "quickly unraveling" in the Atlantic Basin hundreds of miles east of the Northern Leeward Islands, the weather service said. Gert was expected to become a remnant low later Monday and dissipate on Tuesday.

Contributing: Eve Chen, Ken Tran, Claire Thornton, Jordan Mendoza, Josh Peter and Dinah Pulver, USA TODAY; Kate Franco, Palm Springs Desert Sun; The Associated Press