Churning waters about 300 miles south of the southern tip of Baja California, Hurricane Ileana and other storms prompted National Weather Service officials to issue a high surf advisory Thursday morning.
The advisory will be in effect starting 3 a.m. Friday to 6 p.m. Monday.
"Surf is expected to peak Saturday and Sunday," the advisory said.
Waves may reach 6 to 9 feet in some areas and up to 10 feet for southerly facing beaches. Dangerous rip currents are also possible.
Strongest swell is expected to impact conditions from San Clemente to Carlsbad.
The swell may also impact the Imperial Beach shoreline, which was closed Tuesday due to a less than a mile south of the U.S.-Mexico border.
The spill continues, said Mark McPherson with the San Diego County Department of Environmental Health.
At an estimated flow of 70 liters a second, about 4.6 million gallons of untreated sewage have flowed into the Pacific Ocean from Playas de Tijuana.
"Closures will remain in place at least until sewage has stopped, but most likely a little longer especially with the current pushing north," he said. "I can't really predict what's going to happen with the weekend."
Water quality samples taken by environmental health employees found signs of the spill near the border but not in Imperial Beach.
Samples and water conditions observed Friday may determine whether or not the beach is open or closed Labor Day weekend, McPherson said.