Moderate Expected Likely Dense Fog Advisory Dense Fog Advisory issued December 16 at 12:41PM PST until December 17 at 10:00AM PST by NWS San Diego CA Dec 16, 6:00 PM → Dec 17, 10:00 AM WHAT: Visibility reduced to one quarter of a mile or less indense fog. WHERE: Orange County Coastal Areas, Orange County Inland Areas,and San Diego County Coastal Areas. WHEN: From 6 PM this evening to 10 AM PST Wednesday. IMPACTS: Low visibility could make driving conditions hazardous. + Read More If driving, slow down, use your headlights, and leave plenty of distance ahead of you. Updated: Dec 16, 6:34 PM Source: NWS Alert