A Christmas Day atmospheric river dumped up to 12 inches of rain on Southern California's mountains, triggering mudslides that buried roads in Wrightwood and forced helicopter rescues from rooftops. More than 120 emergency responders rescued residents trapped in vehicles and homes overnight Christmas Eve.
At least three to four people died, and Governor Gavin Newsom declared emergencies in six counties covering 28 million people. By December 26, the worst of the storm had passed, though flood risks persisted through Friday evening.
These floods hit burn scars from massive wildfires earlier in the year. Charred soil repels water like pavement, and half an inch of rain can unleash catastrophic debris flows.
California is trapped in a climate whipsaw. Severe droughts fuel megafires that strip mountainsides bare. Then intensifying atmospheric rivers slam the exposed slopes, mobilizing millions of cubic yards of mud, boulders, and debris into populated valleys below.
The 2018 Montecito debris flow killed 23 people in minutes. Now every major wildfire creates a ticking time bomb, armed when the next atmospheric river arrives. With climate change doubling California's megaflood risk and burn acreage expanding, the state faces an escalating cycle it hasn't figured out how to break.
21 events
Latest: December 26th, 2024 · 1 year ago
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December 2024
Storm Conditions Begin to Ease
LatestWeather Event
Atmospheric river expected to wind down Friday evening; flood watches remain through Friday as saturated soils pose ongoing debris flow risk.
Death Toll Rises to Three
Casualty
Woman in 70s swept into ocean by wave in Mendocino; third fatality confirmed.
Second Atmospheric River Intensifies Christmas Day
Weather Event
NWS warns life-threatening conditions continue; 28 million under flood watches.
San Bernardino Mountains Record 10-12 Inches Total Rainfall
Weather Event
48-hour rainfall totals reach 10-12 inches in mountain areas, overwhelming drainage and triggering widespread debris flows.
Additional Storm Fatalities Confirmed
Casualty
San Diego man killed by falling tree; Sacramento sheriff's deputy dies in weather-related crash.
Santa Barbara Airport Closes Due to Flooding
Infrastructure Impact
Airport closes Thursday afternoon as floodwaters inundate airfield.
Newsom Declares State of Emergency in Six Counties
Government Action
Emergency covers LA, Orange, Riverside, San Bernardino, San Diego, Shasta counties.
Wrightwood Evacuations Begin as Flooding Overwhelms Town
Emergency Response
120 firefighters rescue residents trapped in vehicles and on rooftops; Highway 2 impassable.
Airport Fire Burn Scar Evacuation Orders Issued
Emergency Response
Orange County orders evacuations in Trabuco Creek, Bell Canyon, Hot Springs Canyon.
First Storm-Related Fatality Reported
Casualty
74-year-old man dies trapped in pickup truck on flooded Shasta County roadway.
Power Outages Reach 125,000 Customers
Infrastructure Impact
PG&E reports widespread outages across Northern California from high winds.
Airport Fire Burn Scar Evacuations Lifted
Emergency Response
Orange County lifts all evacuation orders and road closures for Trabuco Creek, Bell Canyon, and Hot Springs Canyon near Airport Fire burn scar.
Massive Wrightwood Rescue Operation
Emergency Response
More than 120 emergency responders from multiple jurisdictions work overnight rescuing dozens trapped by flooding and debris flows; helicopter rescues from rooftops.
First Atmospheric River Makes Landfall
Weather Event
Heavy rain begins across California, intensifying overnight into Christmas Eve.
Los Angeles Activates Emergency Operations Center
Emergency Response
Mayor Karen Bass declares local emergency, mobilizes city resources.
State Pre-Positions Emergency Resources
Emergency Preparation
300+ personnel, 55 fire engines, 10 swiftwater teams deployed statewide before storm arrival.
National Weather Service Issues Rare Level 3 Flood Risk
Weather Warning
NWS warns of 'dangerous scenario' with 4-8 inches forecast for valleys, 8-12 for mountains.
USGS Issues Debris Flow Hazard Assessments
Scientific Warning
Federal scientists map burn scar debris flow risk for Airport Fire area.
November Atmospheric River Drenches Northern California
Weather Event
Santa Rosa records wettest day ever with 6.92 inches, presaging pattern.
September 2024
Airport Fire Ignites in Orange County
Wildfire
Massive wildfire burns thousands of acres, creating vulnerable burn scar.
Historical Context
3 moments from history that rhyme with this story — and how they unfolded.
1 of 3
January 9, 2018
2018 Montecito Debris Flow
Three weeks after the massive Thomas Fire burned 281,893 acres, a brief intense rainstorm dropped 0.54 inches of rain in five minutes on the burn scar above Montecito, California. The charred, water-repellent soil triggered debris flows that mobilized 680,000 cubic yards of sediment, including boulders larger than 13 feet, down steep slopes at speeds up to 13 feet per second. The mud and debris buried the affluent Santa Barbara County community in minutes, catching many residents in their homes.
Then
23 people died, 167 injured, 408 homes damaged or destroyed; second-deadliest debris flow in U.S. history.
Now
USGS expanded post-fire debris flow assessments; California strengthened burn scar early warning protocols and evacuation planning.
Why this matters now
The Montecito disaster established the template for California's current crisis: wildfires strip slopes, atmospheric rivers trigger debris flows, and populated areas built into mountain-valley interfaces face catastrophic risk with only minutes of warning.
2 of 3
December 26, 2022 - January 17, 2023
Winter 2022-2023 Atmospheric River Sequence
Nine atmospheric rivers hammered California in 22 days, dumping record-breaking rain and snow. The relentless sequence saturated soils, overwhelmed drainage systems, and caused widespread flooding, power outages, and mudslides across the state. Sacramento recorded its wettest 16-day period in history. Rivers crested above flood stage, levees failed, and entire communities were evacuated. The storms killed 21 people and damaged thousands of structures.
Then
21 deaths, over $3 billion in economic losses, mass evacuations, infrastructure damage across multiple counties.
Now
Demonstrated that clustered atmospheric rivers cause exponentially more damage than isolated storms; prompted increased focus on sequential storm planning and flood infrastructure modernization.
Why this matters now
Stanford research on this event proved back-to-back atmospheric rivers cause three to four times more damage than they would individually, making California's current pattern of closely-spaced storms especially dangerous and highlighting infrastructure vulnerabilities.
3 of 3
February 4-5, 2024
February 2024 Southern California Atmospheric Rivers
Two powerful atmospheric rivers struck Southern California in rapid succession, bringing the wettest two-day period in Los Angeles history since 1893. Downtown LA received 7.03 inches in 48 hours. The storms triggered extensive flooding, knocked out power to 850,000 people, caused mudslides, and forced evacuations. Beverly Hills recorded its wettest day ever. The intensity overwhelmed urban drainage systems and saturated hillsides, causing debris flows in several areas.
Then
850,000 lost power, extensive flooding across LA Basin, evacuations, states of emergency declared in multiple Southern California counties.
Now
Exposed Southern California's vulnerability to intense atmospheric rivers previously considered primarily a Northern California threat; accelerated climate adaptation planning.
Why this matters now
Demonstrated that atmospheric rivers now threaten Southern California with historic intensity, not just the northern part of the state, and that LA's infrastructure wasn't designed for the rainfall volumes climate change is delivering.
