A powerful atmospheric river is poised to impact Northern California starting Monday, with a subsequent system set to reach Los Angeles County on Tuesday. This weather event brings renewed hope for a significant reduction in the fire weather season that has plagued Southern California.
Forecasters predict that the atmospheric river will be particularly intense in Northern California, prompting a flood watch across the region from Monday afternoon until Wednesday morning. Heavy snowfall is also expected in the Sierra Nevada mountains, where conditions could become hazardous.
In Los Angeles County, meteorologists have identified two separate storm systems developing rather than a single storm. Rose Schoenfeld from the National Weather Service in Oxnard indicated that rain will likely fall from Tuesday through Friday across both Los Angeles and Ventura counties. The first storm is expected to peak between Tuesday night and Wednesday midday, while a second, colder front will arrive Thursday into Friday.
Rainfall estimates for Los Angeles County range from a quarter inch to one inch. Specific predictions include approximately one-third of an inch in Covina, two-fifths of an inch in Long Beach, and around half an inch in downtown Los Angeles, Santa Clarita, and Redondo Beach. Canoga Park might see slightly higher amounts at three-fifths of an inch.
As the storm approaches, forecasters warn of potential mudslides and road erosion, especially in areas affected by recent wildfires. There is a 5% chance that rainfall rates could reach levels that pose significant risks for mudslides in these vulnerable regions. Winds are expected to pick up, with gusts of 10 to 20 mph in urban areas and 20 to 40 mph in mountainous regions.
For counties further north, including Ventura, Santa Barbara, and San Luis Obispo, the storm’s peak will occur between Tuesday at noon and Wednesday at 8 a.m. Rainfall rates in these areas may reach up to three-quarters of an inch per hour, with total accumulations varying widely based on location.
The second storm, anticipated to be stronger, is expected to hit Los Angeles County between Thursday night and Friday morning. This system carries a 10% chance of thunderstorms, particularly on Thursday. Rainfall rates during this period could also range from one-quarter to half an inch per hour, with localized areas potentially experiencing more intense rainfall.
While the initial atmospheric river brings light to moderate rain to Los Angeles County, the storm hitting Northern California is classified as strong, with San Francisco forecasted to receive between 3 to 4 inches of rain. The Sierra Nevada could see up to 3 feet of snow at higher elevations, creating hazardous conditions in some areas.
This series of storms marks the first atmospheric river event of the winter for Los Angeles County, and while it is expected to provide beneficial moisture, the potential for mudslides and flooding remains a concern. Residents are urged to stay informed and prepare for the incoming weather systems.