Severe Flash Flood and Blizzard Warnings Issued For Los Angeles County, California

The National Weather Service issued a severe flash flood warning for Los Angeles County on Friday afternoon, warning of worsening flooding as the evening hours approached. A rare blizzard warning was issued for the mountains of Ventura, Los Angeles and San Bernardino counties, with peak rain rates of 0.75 of an inch per hour possible.[0] Flash flood warnings have been issued for Simi Valley, Moorpark, and Santa Paula until 1 a.m., and for Los Angeles, Glendale, and Santa Clarita until 2 a.m.

The storm has already hit Northern California, leaving a mess in its wake, and is gaining strength and moisture as it moves south off the Pacific coast.[1] It is tapping into an atmospheric river system, an enhanced plume of moisture that can deliver large amounts of precipitation.[1]

The storm has already set multiple precipitation records in and around Los Angeles, including 4.61 inches of rain near Hollywood Burbank Airport — its fifth wettest day ever.[2] The dousing is a welcome reprieve from the prolonged and devastating drought that California has experienced.[3]

The storm has caused widespread closures and disruptions, including Interstate 5 through a high-elevation section known as the Grapevine north of Los Angeles, which was shut down Friday morning due to the snow.[3] Thousands of customers remain without power in Southern California, and a voluntary evacuation warning has been issued for the Silverado Canyon and Williams Canyon area due to possible debris flows along or near the burn scar.[4]

The National Weather Service has warned of heavy snow and gusting winds that will create dangerous conditions in the mountains, and an avalanche expert at the weather service has concerns about steep terrain in mountain areas where snow and wind combine.[5]

Forecast calls for snow and rain to continue throughout the weekend, with peak rain rates of 0.75 of an inch per hour possible.[5] Riverside County valleys can anticipate temperatures in the 40s and 50s during the day, and dropping to the 30s at night.[6] Temperatures in mountainous regions are predicted to be in the low 20s during the night, with a potential decrease to the teens on Saturday night.[7] Going north from the Los Angeles area remains a challenge, as the I-5 in the Tejon Pass/Grapevine region has experienced irregular shutdowns.[8]

0. “Unprecedented snowfall possible in California as wind and bitter cold continue” The Washington Post, 25 Feb. 2023,

1. “Photos: Storm moving into SoCal: ‘We’re getting the full brunt’” The San Diego Union-Tribune, 24 Feb. 2023,

2. “More than 126,000 without power in California as storm brings rain, heavy snow, damaging winds” Yahoo! Voices, 25 Feb. 2023,

3. “‘Strongest snowstorm in years’ leaves Californians delighted and frozen” The Guardian US, 25 Feb. 2023,

4. “Live updates: Flash Flood Warning issued for Los Angeles County” KTLA Los Angeles, 24 Feb. 2023,

5. “Live updates: Storm brings snow, rain and blizzard warning for Southern California” VC Star, 24 Feb. 2023,

6. “Blizzard conditions, wet and freezing weather set in across Southern California” OCRegister, 24 Feb. 2023,

7. “SoCal blizzard live updates: Heavy winds rock valley Saturday; ‘blizzard conditions' in nearby mountains” Desert Sun, 25 Feb. 2023,

8. “Thousands Are Without Power, Beaches Closed For Lightning As Winter Storm Continues” LAist, 25 Feb. 2023,