Continued Flood Threat For Southern California As Atmospheric Rivers Target The State Through Friday
- - Continued Flood Threat For Southern California As Atmospheric Rivers Target The State Through Friday
Jonathan Belles December 25, 2025 at 6:43 PM
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A dangerous flood and landslide threat prompted a rare "high risk" forecast for Southern California on Wednesday, as a series of storm systems target the state this Christmas week, including areas soaked last weekend in Northern California and the L.A. Basin.
The risk of excessive rain and flash flooding is lower for Christmas Day, though the risk is still notable and any additional rainfall will be falling on top of already flooded roadways.
How Much Rain Has Already Fallen
Multiple stations in the Tranverse Ranges mountain region have reported 48 hour rainfall totals over 10 inches, and the Cogswell Dam in Los Angeles County received a storm total of 9.65 inches.
As of noon on Wednesday, Oxnard had already received over 2 inches of rain since midnight, making it the rainiest Christmas Eve in the Oxnard area since the records began in 1923 (the existing record is 1.24 inches).
Strong winds are also buffeting the region, with an 98 mph gust reported by a station on Magic Mountain.
(MORE: Latest California News)
High Risk For Flooding
The latest in a series of storms tapping deep plumes of moisture known as atmospheric rivers has meteorologists particularly concerned.
In their excessive rainfall outlook, NOAA's Weather Prediction Center issued a rare "high risk" for parts of Southern California for Wednesday and Wednesday night.
According to NOAA/WPC, these high risk forecasts are only issued on about 4% of days, but have accounted 36% of all flood deaths and 80% of all flood-related damage in the U.S.
This heavy rain has been triggering flash flooding and landslides, particularly in hilly and mountainous terrain and areas recently burned by wildfires.
At times, rain will also fall at higher elevations than usual in these atmospheric river events, potentially melting existing snowpack adding to the threat of flash and river flooding.
Of particular concern are the mountains of Santa Barbara, Ventura, L.A. and San Bernardino Counties, as well as the surrounding L.A. Basin. It's here where the risk of rockslides, mudslides, debris flows and more widespread, life-threatening flash flooding is highest.
Be prepared to evacuate immediately if urged to do so by local authorities. Never drive through a flooded area.
This threat of locally flooding rain will also extend into the Desert Southwest, where flood watches are in effect. Expect localized urban flash flooding with water running in normally dry washes and arroyos, including the Vegas Valley.
A moderate risk, or a level 3 out of 4 risk, has been issued for Christmas for much of the Southern California mountains and the Los Angeles basin.
Timing
Happening Now: A band of heavy rain, the atmospheric river, is moving eastward through California and is hammering Southern California. You can see where rain and snow are occurring on the radar map below.
Strong winds with the next two Pacific storms will down trees and knock out power, particularly in areas where the ground is soaked. Some gusts could reach 60-80 mph in the highest terrain of Southern California. Wind gusts up to 55 mph are possible in the L.A. Basin.
Christmas Day - Friday: A second strong Pacific storm is forecast to surge into California Christmas Day, with a second round of heavy rain, strong winds and heavy Sierra snow. A few strong thunderstorms are possible right along the coast from San Francisco to Los Angeles on Christmas, including a brief tornado or two. Rain showers and mountain snow will linger into Friday. Some locally heavy showers are also possible in parts of the Desert Southwest both days.
Weekend: While a few showers may linger in the Four Corners Saturday, California and the rest of the Desert Southwest will dry out once again.
How Much More Rain, Snow
- Northern California: Widespread 3-inch-plus additional rainfall totals through Friday, with locally 5-inch-plus rainfall are likely in the coastal ranges and foothills of the northern and central Sierra, below snow level. Parts of the Bay Area could see another 1 to 5 inches of rainfall, which would equal about a month's worth of rainfall for San Francisco.
- Southern California: The L.A. Basin from Santa Barbara to Orange County is expected to pick up at least 3 inches of total rain during the Christmas week storms. Higher amounts are likely in the Southland mountains below snow level, where some 8-inch-plus totals are expected, especially along south-facing slopes and foothills. San Diego County may also pick up at least 2 inches of total rainfall. The heaviest rainfall for the region, with rain rates possibly over an inch per hour, is expected Wednesday and Wednesday night, then again Thursday afternoon and night.
- Mountain snow: Several feet of Sierra snow is expected in total from Tuesday night through Friday. The California snowpack is running significantly behind schedule, so this snowfall is very needed.
Additional Rainfall, Snowfall TotalsMost Californians Under At Least One Weather Alert
Outside of the southeastern portion of the state, everyone in California is in some sort of weather watch or warning issued by the National Weather Service. Some of those alerts have been depicted on the map below, but it is not an exhaustive list of alerts. Some advisories and watches are not shown.
Many communities are under multiple watches and warnings.
To see what alerts and threats your family faces this holiday week, please open The Weather Channel app on your phone and put your location into the search bar.
Recap
The most recent atmospheric river dumped anywhere from 3 to 14 inches of rain in Northern California's coastal ranges and Sierra foothills from last Saturday night through Monday.
That lead to 69 reports of flooding, 31 reports of landslides and another 22 reports of wind damage in the state from Saturday night through Monday. Among the most serious flash flooding occurred in and near Redding, in far Northern California, where water rescues occurred.
(MORE: Impacts In California)
Jonathan Belles has been a digital meteorologist for weather.com for 9 years. His favorite weather is tropical weather, but also enjoys covering high-impact weather and news stories and winter storms. He's a two-time graduate of Florida State University and a proud graduate of St. Petersburg College.
Source: “AOL Breaking”
