California faces rare flooding threats, Southern California enters high-risk emergency period

California Meteorological Department Continues to Issue Warnings: This Round of Heavy Rainfall Is Increasing the Risk of Local Flooding, and the Southern California Coastal Area Has Been Raised to a High Alert Level. As a result, Los Angeles County officials have extended the evacuation order until 1 PM Friday, affecting hundreds of thousands of residents.

Chain Reaction of Meteorological Disasters

The National Weather Service reports that the precipitation brought by this storm has broken historical records. By Friday morning, the entire state of California was under moderate to heavy rainfall, with coastal areas from Oxnard to Malibu becoming high-risk zones for flash floods. The southern California coast is also facing threats from strong winds and thunderstorms.

According to data from the National Power Outage Tracking System, over 50,000 households and commercial facilities experienced power outages on Friday morning alone. Northern California has the most severe outages. This heavy rainfall has resulted in at least 3 fatalities.

Post-Wildfire Risks Amplify

The underlying cause of this disaster is closely related to wildfires from a year ago. Vegetation in burned areas has been destroyed, creating a hydrophobic layer on the ground surface, severely impairing the soil’s water absorption capacity. This means each rainfall could trigger landslides and mudslides, with dangers far exceeding typical flood risks.

Meteorologists state that soils burned by wildfires take a very long time to recover. According to assessments from the Weather Forecast Center, such burned areas require 4 to 5 years for the soil’s permeability to gradually improve. Until then, every heavy rain in Southern California increases the risk of secondary disasters. Experts point out: “Rainwater falling on these areas acts like hitting concrete surfaces—it cannot infiltrate and instead forms rapid runoff, which is the cause of flash floods and mudslides.”

Travel Disruptions During the Holidays

The Christmas holiday coincides with this heavy rainfall event, leading to road closures in many areas, frequent flight delays at airports, and flooding on highways. Public travel plans are severely affected, and authorities have issued safety warnings to all drivers.

Interpretation of the Atmospheric River Phenomenon

This rare rainfall event originates from a massive storm system over the Pacific Ocean, known as an “atmospheric river”—a meteorological phenomenon capable of transporting large amounts of water vapor in a short period. Such storms often bring sudden heavy rainfall, easily triggering flood disasters.

Currently, Los Angeles County has activated emergency plans. Residents are advised to evacuate high-risk areas proactively. Authorities continue to monitor rainfall patterns and update warnings in real time.