The dense morning fog that blanketed the western valleys and coastline this week is expected to clear up Friday ahead of a west-northwest swell that will bring high surf to the beaches Friday afternoon through the weekend.
A National Weather Service dense fog advisory for coast and valleys of San Diego County is set to remain in effect until 8 a.m. Friday. Areas of fog are expected to extend 10 to 15 miles inland from the beaches, and could affect travel along portions of Interstates 5, 8, 15 and 805 and on state Routes 52, 56, 78, 94 and 163.
Motorists were advised to use extra caution as visibility could be reduced to a quarter-mile at times. Drivers were urged to slow down, use low beams and leave plenty of distance in front of them.
Forecasters said delays at area airports may be possible.
The fog is expected to let up around 8 a.m., but the beaches won't be in the clear for long. A high surf advisory is set to take effect at 3 p.m. Friday and extend until 3 p.m. Sunday.
Sets of up to 8 feet are expected south of Del Mar. Forecasters said strong rip currents are also likely throughout the advisory period and minor coastal flooding is possible during the highest tides, forecast to be 6.6 feet at 7:30 a.m. today, 6.5 feet at 8:10 a.m. Saturday and 6.4 feet at 8:54 a.m. Sunday.
Clouds will also build Friday afternoon as a storm approaches. This will bring cooler temperatures through the weekend with isolated light showers Saturday afternoon and evening along and west of the mountains.