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Weather Forecast for Thursday, Dec. 18
The latest forecast and air quality conditions for the greater Los Angeles area, including beaches, valleys and desert regions.
LOS ANGELES - Southern California is bracing for a significant weather shift as a powerful atmospheric river is forecast to arrive just in time for the Christmas holiday.
What we know:
The National Weather Service has confirmed that a moderate-to-strong atmospheric river is expected to impact California between December 23 and December 26.
In Southern California, coastal and valley areas are projected to receive 2 to 4 inches of rain, while foothills and mountainous regions could see as much as double those amounts.
Northern California and the Sierra Nevada are at high risk for heavy precipitation beginning as early as Sunday, December 21.
Rain Chances
Timeline:
Los Angeles County
- Tuesday, Dec. 23: 10-20%
- Tuesday night: 30-50%
- Wednesday, Dec. 24: 80-100%
- Wednesday night: 80-100%
- Thursday, Dec. 25: 60-70%
- Thursday night: 30-50%
- Friday, Dec. 26: 30-50%
- Friday night: 10-20%
Ventura County
- Tuesday, Dec. 23: 10-20%
- Tuesday night: 30-50%
- Wednesday, Dec. 24: 80-100%
- Wednesday night: 80-100%
- Thursday, Dec. 25: 60-70%
- Thursday night: 30-50%
- Friday, Dec. 26: 30-50%
- Friday night: 10-20%
Santa Barbara County
- Tuesday, Dec. 23: 30-50%
- Tuesday night: 60-70%
- Wednesday, Dec. 24: 80-100%
- Wednesday night: 80-100%
- Thursday, Dec. 25: 60-70%
- Thursday night: 30-50%
- Friday, Dec. 26: 30-50%
- Friday night: 10-20%
Orange County
- Tuesday, Dec. 23: 47%
- Wednesday, Dec. 24: 76%
- Thursday, Dec. 25: 59%
- Friday, Dec. 26: 54%
Riverside County
- Tuesday, Dec. 23: 30%
- Wednesday, Dec. 24: 70%
- Thursday, Dec. 25: 56%
- Friday, Dec. 26: 25%
San Bernardino County
- Tuesday, Dec. 23: 30%
- Wednesday, Dec. 24: 69%
- Thursday, Dec. 25: 67%
- Friday, Dec. 26: 24%
What they're saying:
Forecasters are urging the public to stay alert despite some lingering variables in the forecast.
Regarding the incoming system, the National Weather Service shared on social media, "Exact timing uncertain. Amounts and impacts also uncertain, but this chart shows the chance of each potential outcome. Start to mentally prepare for a wet Christmas holiday."
Why you should care:
The timing of these storms coincides with the peak holiday travel window, raising significant safety concerns for motorists.
The National Weather Service is highlighting several specific dangers associated with this system:
- Road conditions: Heavy rain following a long dry spell can lead to exceptionally slick roads. Major mountain passes, such as the Grapevine, may face closures or strict chain requirements due to snow.
- Flooding and debris: There is an elevated risk of flash flooding and landslides, particularly in areas recently scarred by wildfires where the soil is less able to absorb moisture.
- Utility disruptions: The combination of wet ground and gusty winds increases the likelihood of downed trees and potential power outages.
What you can do:
Officials are reminding the public to monitor the latest forecast updates as the holiday approaches.
For those planning to drive through mountain passes, it is recommended to carry snow chains, maintain a full tank of gas, and have a winter emergency kit ready.
At home, residents should clear rain gutters and secure outdoor holiday decorations or inflatables before winds intensify mid-week.
The Source: This report is based on information from the National Weather Service, the Weather Channel, and Accuweather.