Flash flooding wreaks havoc on Los Angeles area as powerful storm slams into Southern California

Southern California continues to face a dangerous flood threat through Friday as heavy rain targets the Los Angeles and San Diego areas, before moving eastward.

More than 20 million people from Southern California through central Arizona remain under a Flood Watch as rainfall totals surpassed 10 inches in several mountain areas, while bringing a month’s worth of rain in an hour in Ventura County.

The overall rainfall amounts combined with the potential for bursts of thunderstorm-triggered heavier rain, especially over recent wildfire burn-scar areas, prompted NOAA’s Weather Prediction Center (WPC) to put a swath of Southern California in a Level 3 out of 4 risk zone for flash flooding.

For many communities, the precipitation is the heaviest rainfall event since the remnants of Hurricane Hilary impacted the region in August.

Some of the hardest hit areas included Oxnard and Santa Barbara, where water rescues were needed.

A good Samaritan driver pulled two people from a vehicle before it was swept away and the American Red Cross opened at least one shelter.

Oxnard, Port Hueneme residents wake up to flooded homes

Significant flash flooding occurred in the Oxnard area, the largest city in Ventura County, after 3.18 inches of rain fell in one hour – of which 2.25 inches fell in just 30 minutes.

The city averages about 2.5 inches of rain for the entire month. Overall storm totals were nearing 6 inches at the city’s civic center by Thursday evening. 

Photos shared on social media from Oxnard showed upwards of 2 feet of water on roads.

Larry Emerson, a resident of Port Hueneme in Ventura County, says he awoke to a frustrating sight Thursday morning when he found about a foot of water had seeped into his garage.

“Everything is wet and about a foot up on everything,” he said. “The deluge must have gone through the entire garage. I got boxes destroyed… (The floodwaters) tipped over a commercial vacuum cleaner and got water on the inside. It was so forceful.”

About 60 homes were flooded, and even a senior living center had to be evacuated. First responders had to use high-wheeled vehicles to evacuate about 20 people.

During the peak of the flooding, Ventura County Fire reported that they received approximately 275 calls within a span of five hours, according to public information officer Andy VanSciver. That is significantly higher than their usual call volume of less than 200 calls per day.

“This storm was a little bit unique to the Port Hueneme, Oxnard area. This is a coastal community, so it’s rather flat to begin with here by the ocean,” VanSciver said.

“And so the flood control channels were overwhelmed. I did hear on my response in as I was gathering information both on the police radio and the FM radio that the National Weather Service was reporting that it had received an enormous amount of rain.

“Sometimes they were saying maybe more than we’ve ever received in the last 30 to 40 years in such a short period of time.”

As much as 8 inches of rain expected

By the end of the week, between 5 and 8 inches of rain is forecast to fall in several areas, with some places experiencing even higher amounts, keeping an ongoing risk of flash and urban flooding.

Some mountainous areas in Southern California reported rainfall totals over 10 inches through the week as of Thursday evening. 

Rocky Butte in San Luis Obispo County reported 15.95 inches, while Ventura County’s Old Man Mountain had 13.70 inches, according to the National Weather Service.

Closer to the metro area, Beverly Hills had 2.66 inches of rain while Los Angeles’s LAX airport reported 2.15 inches. 

Severe weather jolts residents as Tornado Warnings issued in Ventura County

For some, the storms didn’t just bring heavy rain and flooding, but a threat of severe weather.

Early Thursday morning, two Tornado Warnings were issued for the Oxnard area after Doppler Radar indicated possible rotation inside passing thunderstorms.

The Tornado Warnings were the first issued by the National Weather Service’s Los Angeles office during the month of December since 2008.

“At one point, we had over 350,000 people under a Tornado Warning and also a Flash Flood Warning,” FOX Weather Meteorologist Britta Merwin said.

Snow blankets the Sierra Nevada

The same system is also dropping heavy snow over the highest elevations of California’s Sierra Nevada Mountains, with lower snow amounts over the highest elevations of the Washington and Oregon Cascades and parts of Idaho and Nevada.

Rain was forecast to slowly head east through the day Friday, drying out Southern California from west to east and shifting heavy rains and the flooding threat into parts of Arizona.