The high-pressure system that kept skies clear and temperatures warm is weakening, allowing fog and clouds to roll into San Diego County this weekend.
An air mass, warmed by balmy days, will cause air over the ocean to condense into low clouds or fog, said Wilbur Shigehara, a National Weather Service forecaster.
Dense fog is expected to blow in from the ocean shortly after sunset today and not burn off until mid-morning, he said. (Flights at Lindbergh Field may be delayed or canceled during the weekend if visibility becomes too poor, an airport spokesman said.)
However, after the fog burns off, days should be fair with slightly hazy sunshine through Sunday. Temperatures at the coastal areas through the weekend will be about 65, with nighttime lows about 50 degrees.