Pineapple Express headed to Southern California for Christmas: What to know
Weather Forecast for Saturday, Dec. 20
The latest forecast and air quality conditions for the greater Los Angeles area, including beaches, valleys and desert regions.
LOS ANGELES - A powerful "Pineapple Express" atmospheric river is set to drench Southern California in the coming days, threatening much of the region with record-breaking rainfall and significant travel disruptions as the Christmas holiday approaches.
Southern California weather outlook for Christmas
What we know:
A potent atmospheric river drawing tropical moisture from Hawaii is currently shifting southward toward Southern California.
According to the National Weather Service, this storm will bring several inches of rain to the region starting Tuesday, Dec. 23, and continuing through Christmas Day.
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Coastal and valley areas are expected to receive two to four inches of rain, while the foothills and mountains could see up to double those amounts.
In downtown Los Angeles, there is an 80% chance of receiving two or more inches of rain; the last time that occurred over the Christmas holiday was in 1971.
Rain timeline
Timeline:
The storm is expected to arrive in phases, with conditions deteriorating as the holiday approaches:
Saturday, Dec. 20 – Monday, Dec. 22: The primary moisture plume focuses on Northern California and the Bay Area before sagging south.
Tuesday, Dec. 23: Light showers may begin in coastal Southern California, with rain intensity increasing Tuesday night into Wednesday morning.
Wednesday, Dec. 24 (Christmas Eve): The peak of the storm is expected, bringing drenching downpours and the highest risk of urban flooding.
Thursday, Dec. 25 (Christmas Day): Additional lighter showers are expected to continue through the day as the system moves through the area.
Why this storm matters for your holiday travel plans
Why you should care:
This storm coincides with one of the busiest travel periods of the year.
AAA estimates that over 10 million people will be traveling through Southern California during the holiday period, a 2% increase from last year.
RELATED: Holiday travel 2025: Record 10.2 million SoCal travelers to hit the road
Heavy rainfall increases the risk of road accidents, power outages, and airport delays.
Low-lying areas and recently burned regions susceptible to mudslides, face heightened flood threats.
Expert predictions for the Christmas week storm
What they're saying:
Officials and meteorologists are urging the public to prepare for a "wild" weather week.
"Anyone with holiday travel plans by road and by air should keep an eye on the forecast and adjust accordingly," the National Weather Service advised in an online forecast.
Alex Sosnowski, AccuWeather senior meteorologist, noted that "Drenching downpours and urban flooding problems are predicted to occur in the Los Angeles and San Diego metro areas from Wednesday Dec. 24 to Friday Dec. 26, which may spoil outdoor Christmas-related activities."
The National Weather Service in Los Angeles added a simple directive for residents: "Start to mentally prepare for a wet Christmas holiday."
How to stay safe
What you can do:
People are encouraged to take proactive steps before the heaviest rain arrives on Tuesday night:
- Clear leaves and debris from rain gutters and storm drains near your home.
- Secure outdoor decorations and trash bin lids against potential wind gusts.
- Check flight statuses frequently if traveling through local airports like LAX or San Diego International.
- Slow down and leave extra space between vehicles when driving on wet freeways.
- Sign up for local emergency alerts to stay informed about flash flood warnings or evacuation orders.
The Source: This report is based on current meteorological data and public safety advisories issued by the National Weather Service and AccuWeather. Information regarding holiday transit impacts was provided by AAA and local transportation authorities, including San Diego International Airport, based on their 2025 seasonal travel projections and flood mitigation records. City News Service contributed.