LOS ANGELES - Southern California is bracing for significant weather changes as a series of storms are set to impact the region starting this week, bringing moderate to heavy rain, mountain snow, and elevated risks of flooding.
According to the National Weather Service (NWS), after experiencing one last day of sunny conditions on Monday, March 10, 2025, the storm system is expected to begin its effects from Monday night through Thursday.
The first storm, arriving late Monday, is projected to bring light rain and possible mountain snow, particularly impacting areas at elevations above 6,500 feet. The heaviest precipitation from this initial storm is anticipated from late Monday night to early Tuesday morning. Although rainfall totals from this storm will be lower than the following system, they are still expected to strain local drainage systems. “A moderate to strong winter storm will likely bring periods of moderate to heavy rain and mountain snow to Southwest California from Wednesday to Thursday,” the NWS reported.
On Tuesday, March 11, light rain is expected, with forecasts predicting totals of less than 0.25 inches. Forecasts also indicate temperatures will hover between the high 50s and low 60s across Los Angeles and Ventura counties. A total rainfall estimate for the second storm, set to arrive Wednesday, March 12, is much more significant: projections show 1 to 2 inches in coastal and valley areas and 2 to 4 inches across foothills and mountains. Rainfall rates could exceed 0.50 inches per hour at the storm's peak.
Meteorologist Jason Farhang noted on social media, “The weather will start changing later this afternoon at 3 PM as this cut-off low has now fixated its...,” forecasting thunderstorms developed within the system after 7 PM on Tuesday. These could be especially prominent as the second storm moves through.
Residents have been warned of various hazards due to the impending storms:
- Urban and Small Stream Flooding: Heavy rainfall could overwhelm drainage systems, with localized flooding expected across urban areas.
- Mudslides and Debris Flows: Recent burn areas remain highly susceptible to landslides during intense rainfall episodes.
- Hazardous Travel Conditions: Significant snowfall, particularly over 6,000 feet, could lead to dangerous travel conditions due to snow-covered roads and reduced visibility.
The NWS has issued Flood Watches for affected areas from 4 PM Wednesday, March 12, to noon Friday, March 14. With the impact of heavy rains, there are also concerns of shallow debris flows if thunderstorms develop over areas recently impacted by wildfires.
For the second storm, forecasts predict temperatures will remain relatively cool, and it is believed to bring the most significant snowfall of the season to higher elevations, with totals of up to 2 feet expected above 6,000 feet. The forecasts point to as much as 12 to 24 inches of snow forecast for mountain regions above 6,500 feet by the time the storm wanes.
One significant concern raised by meteorologists is the likelihood of the strongest storm effects occurring during Wednesday night through early Thursday, with roughly 75% of the total rainfall forecasted for the second storm occurring within this peak period. Travel could become very difficult during this time, especially for mountain areas.
Residents have been advised to stay informed by monitoring local news updates on the storm developments. Preparations for possible power outages, tornado winds, and securing outdoor items are highly recommended.
With another weather system looming for the next weekend, Southern California will face additional rain on Saturday and Sunday, March 15 and 16, continuing the tumultuous weather period.
Local authorities urge residents to take these advisories seriously and prepare adequately. Keeping informed and ready can make all the difference as these late-winter storms approach.