Southern California is preparing for a sharp shift in weather. Tropical Storm Rachel is approaching the region and combining forces with a separate low-pressure system moving in from the north.
Forecasters from the National Weather Service expect cooler temperatures, periods of rain, powerful ocean swells, and hazardous coastal flooding through early next week. Sunday poses the greatest threat of severe coastal conditions.
Showers are expected to begin late Saturday evening, October 10. The highest probability of steady precipitation will occur on Sunday, October 11. Unstable weather conditions may continue through Tuesday, October 13, though overall rainfall totals and severity depend closely on Rachel’s exact track and intensity.
Coastal Flood Warnings and Severe Ocean Impacts
The National Weather Service issued coastal flood warnings through 3 p.m. Sunday for beaches across Los Angeles and Orange counties. Officials warned that damaging coastal flooding is likely along vulnerable south-facing beaches, particularly in Long Beach, Malibu, and parts of Newport Beach. Massive swells in these areas have already triggered local emergency declarations.
In Newport Beach, unusually high tides and powerful waves breached protective 20-foot sand berms at the Wedge. This water inundated low-lying streets on the Balboa Peninsula with over a foot of water. City officials declared a local emergency Friday to ramp up drainage pumping and deploy continuous protective sand barriers.
In Long Beach, destructive waves pounded the Alamitos Peninsula boardwalk and damaged waterfront properties. City crews red-tagged two structures and yellow-tagged three others following the damage.
Forecasters report that high tides reaching 7.3 to 7.6 feet will combine with 4-to-7-foot breaking waves and dangerous rip currents to compound coastal hazards. A high surf advisory remains in effect for the Malibu coast and Los Angeles County beaches. Authorities urge residents and motorists to stay away from hazardous coastal zones and flooded roadways.
Rainfall Totals and Regional Weather Breakdown
Unlike atmospheric rivers that trigger widespread freshwater flooding, the primary hazards from the remnants of Tropical Storm Rachel stem from coastal inundation and high winds. However, measurable rain will still provide significant relief from the prolonged autumn heat wave that recently baked the region.
- Los Angeles and Ventura Counties: Most areas are forecast to receive between a tenth and a half-inch of rain, with locally higher amounts up to an inch in mountain corridors like the eastern San Gabriel Mountains.
- Orange and San Diego Counties: Coastal locations can expect half an inch to an inch of precipitation, while higher mountain elevations like Big Bear and Julian may see up to an inch and a half.
- Inland Empire and Deserts: Desert communities including Palm Springs, Twentynine Palms, and parts of the Mojave Desert face a moderate flash-flood risk as moisture pushes further inland toward Utah and Arizona.
Active Warnings, Advisories, and Timeline
This multi-day weather event follows a rare tropical storm watch issued for San Diego County-marking only the second time such a watch has been declared in California history. Meteorologists attribute the unusual strength and trajectory of the system to record-warm ocean temperatures and El Niño conditions off the coast.
Chronological Storm Timeline
- Saturday Evening: Cloud cover deepens as tropical moisture streams into the region. Light to moderate rain showers begin developing across coastal and valley zones.
- Sunday Morning to Afternoon (Main Peak): The highest probability of rainfall arrives, accompanied by peak coastal flooding threats during morning high tides. Isolated thunderstorms are possible in eastern Los Angeles County.
- Sunday Night through Monday: A second, colder low-pressure system moves in from the north. It delivers a noticeable drop in temperatures, scattered showers, and a continued risk of isolated thunderstorms.
- Tuesday: Remaining showers gradually taper off from west to east as the complex weather system exits the region.
- Wednesday and Beyond: Clear skies and drying conditions return by midweek, setting the stage for a swift warming trend and potential weak-to-moderate Santa Ana winds late in the week.
Local emergency management agencies continue to distribute free sandbags to residents in vulnerable coastal and low-lying areas. Motorists must never drive around barricades or through flooded roads, and beachgoers should remain out of the water until all active warnings expire.
