The National Weather Service has issued a "Hazardous Weather Outlook" for Los Angeles County. Rain is expected on Wednesday thru Friday with a large west swell to impact west facing beaches late Wednesday through Saturday night.
From the The National Weather Service:
A strong storm over the north central pacific will likely generate a large west swell with a relatively long period affecting the coast by late Wednesday night through at least Saturday. this swell will bring the potential for large surf across west facing beaches from the central coast to the Los Angeles Orange County border. Highest surf can be expected Thursday afternoon through Friday. Surf will then diminish some slowly through Saturday night and into Sunday. A high surf advisory will likely need to be issued in the next 24 to 36 hours for the areas mentioned.
Location: west facing beaches including San Luis Obispo …lower Santa Barbara county near Ventura County…Ventura County and Los Angeles county. Also western side of Santa Catalina island.
Surf heights: for exposed west facing beaches…heights will vary greatly. Central coast could see surf 10 to 15 feet with local sets to 20 feet. while the inner waters could see surf 6 to 12 feet with local sets to 15 ft in a few locations including areas near the Ventura harbor and southern Los Angeles County.
Timing: …west swell will build rapidly Wednesday night into Thursday morning…then peak Thursday afternoon into friday…then slowly diminish through the weekend.
Tides: …high tides will peak during mid morning hours to around 6 feet…with the mean high tide around 4 feet during the late evening hours. lowest tide will be around -0.5 feet during late afternoon hours…with the mean low tide around 2 feet during late night hours.
Impacts: …surf and swell conditions could be hazardous to anyone entering the water late Wednesday through this weekend…with dangerous rip current potential. minor beach erosion and localized flooding of low-lying areas may also occur near the peak of the high tide.