[article] Dense fog created problems for travelers Friday night when conditions caused delays at the San Diego International Airport. According to airport operations officials, several flights experienced delays and cancellations at Lindbergh Field due to the fog. Officials said some airplanes were being brought into the airport via reverse approach over the ocean. The National Weather Service (NWS) in San Diego has issued a dense fog advisory, which remains in effect from 8 p.m. Friday through 9 a.m. Saturday. The NWS says higher coastal terrain and western edges of San Diego County valley are the area most impacted by the dense fog. In some parts of the county visibility could be one-quarter-mile or less.