Los Angeles Hit by Devastating Atmospheric River, Flash Flood Warnings in Effect – What Travelers Need to Know

Published on December 25, 2025

A powerful atmospheric river storm has unleashed torrential rains across Southern California, particularly affecting Los Angeles. The Christmas Eve storm has triggered widespread flash flooding and evacuation orders as heavy rains, winds, and mudslides threaten the region’s infrastructure and residents. The storm, which originated as a dense moisture flow from the Pacific, has intensified over the last 24 hours, leading to hazardous travel conditions and escalating emergency responses.

According to the National Weather Service (NWS), the storm is expected to persist through Friday, continuing to impact holiday travel. For those in Los Angeles and surrounding areas, authorities have issued flash flood warnings and evacuation orders, urging residents to stay indoors and avoid non-essential travel.

Atmospheric River Storm Causes Widespread Flooding and Evacuations

The storm, which began as a Pacific atmospheric river, is bringing heavy rain with 1 to 2 inches per hour in some areas, causing rivers to swell and flash floods to occur. This has created treacherous conditions on roads and highways, especially with the Sierra Mountains receiving a combination of rain and heavy snow, complicating the already chaotic travel conditions.

Authorities have reported widespread flooding in Los Angeles County, where flash flood warnings were posted throughout the region, urging residents not to travel unless absolutely necessary. The NWS warned that “life-threatening conditions” were likely to persist as the rain continues through the week. Areas downstream of wildfire scars, especially in Pacific Palisades and Trabuco Canyon, are particularly vulnerable to mudslides and debris flows, which could block access roads and cause more damage.

The storm’s impact on holiday travel has been profound, with traffic delays, flight cancellations, and airport disruptions being reported throughout the region. At Los Angeles International Airport (LAX), travelers are advised to check their flight statuses as thunderstorms and heavy rainfall contribute to delays.

Evacuation Orders and Road Closures Across Los Angeles

City officials have implemented evacuation orders for approximately 130 homes in Pacific Palisades that are especially vulnerable to mudslides and flooding. The Los Angeles Fire Department (LAFD) and emergency services are working tirelessly to ensure the safe relocation of residents in these high-risk zones. Additionally, several roads, including Ortega Highway and Pacific Coast Highway, have been closed or blocked due to fallen trees, rockslides, and flash flooding in mountainous areas.

Officials from the Los Angeles Police Department (LAPD) and California Highway Patrol (CHP) have urged travelers to avoid unnecessary travel in flash flood zones, where roads may quickly become impassable. Traffic congestion is expected, especially as rain and strong winds continue to cause hazardous driving conditions, making highways prone to flooding and accidents.

Heavy Rain and Snow in Mountainous Regions Affecting Travelers

In the Sierra Mountains and higher elevations, the storm has brought heavy snow, with forecasts predicting 12 to 18 inches of snowfall over the next 24 hours. The storm’s combination of rain at lower elevations and snow at higher altitudes is complicating travel to popular winter destinations such as Big Bear Lake and Lake Arrowhead.

Authorities are advising ski resort visitors and travelers heading to mountain regions to prepare for delays and closures as the storm causes blizzard-like conditions in parts of the Sierra Nevada. Mountain passes are particularly at risk, with chains required on vehicles due to snow and ice buildup.

Tornado Warning Issued for Small Portion of LA County

Adding to the already chaotic weather, a rare tornado warning was issued for parts of east-central Los Angeles County, particularly around the community of Alhambra, due to intense thunderstorm activity associated with the storm system. Although the tornado threat was limited, authorities urged residents in the affected area to remain cautious and take shelter in safe locations.

The unusual severity of this warning underscores the unpredictable nature of the current storm and its wide-ranging effects on the region’s weather patterns. It also serves as a reminder of the importance of remaining prepared for sudden weather events that can lead to unexpected disruptions, especially during peak travel periods.

Public Health Concerns and Safety Recommendations

Along with the immediate travel and evacuation concerns, public health officials have raised alarms about the potential for waterborne diseases and health risks associated with standing floodwaters. People are advised to avoid contaminated water and to stay away from areas where flooding has occurred.

Health experts are also recommending that people in affected areas ensure their homes and personal belongings are protected from flooding and avoid venturing outside unless absolutely necessary. Public health advisories have been issued to prevent the spread of illness, particularly in areas where sewage systems may be overwhelmed by the storm.

What Travelers Need to Know

For those traveling to or within Southern California this holiday season, it’s essential to stay informed about weather conditions and travel advisories. Authorities recommend checking flight statuses, road conditions, and weather forecasts regularly to avoid disruptions. Travelers should expect delays at airports, closures of major roads, and possible cancellations of public transport services due to heavy rainfall and flooding.

For those already in the region, emergency shelters and relief centers have been set up, and travelers are encouraged to follow local government instructions and stay off the roads.

Conclusion: A Christmas Storm to Remember

The Christmas Eve storm that has battered Southern California serves as a stark reminder of the unpredictable nature of weather and its potential to disrupt holiday travel. As the storm continues to move through the region, authorities are urging residents and travelers to stay vigilant and prioritize safety above all else. The flash floods, road closures, and evacuation orders make this a challenging time for both residents and visitors in the affected areas, but with preparedness and caution, the situation can be navigated safely.