Moderate showers hit Mission Beach and Interstate 8 through Mission Valley at about 7 a.m. The brunt of the storm is expected bring moderate to heavy rainfall to the region through about 10 a.m., Fox 5 weathercaster Brad Wills said.
Rainfall rates could reach one-half inch per hour, which is sufficient to trigger flash floods and debris flows in and below recent burn areas, according to the National Weather Service. The area of greatest risk is the Cocos Fire burn area in San Marcos.
A flash flood watch for valley areas was scheduled from 3 a.m. through late tonight.
The Weather Service also issued wind advisory for coastal and valley areas until 10 a.m., saying sustained winds early today are likely to be around 20 to 30 miles per hour and gusts will top out at 45 mph.
A beach hazards statement is in effect until 4 a.m., when a more serious high surf advisory will take effect. The Weather Service scheduled the high surf advisory from 4 a.m. today to 10 p.m. Saturday, saying sets of 12 to 14 feet are possible, especially along west-facing beaches.
High surf and strong rip currents will result in dangerous swimming conditions, the NWS said. Waves may over top jetties and sea walls at times.
Showers are expected to taper off late tonight into Saturday morning.