Overview
- An NWS advisory for the I-5 Grapevine and nearby mountain highways remains in effect through Saturday, Dec. 13 at 11 a.m., with visibility down to a quarter mile or less at 1,000–2,500 feet.
- The Orange County coast and San Diego County coastal areas were under a dense fog advisory until 9 a.m. Friday, with forecasters cautioning of quarter-mile visibility.
- The Willamette Valley advisory ran until 10 a.m. Friday, and later observations showed visibility improving above a quarter mile with patchy fog expected to fade late morning.
- Forecasters report the thickest fog near rural areas and water bodies, and they note a chance of lingering early-afternoon fog in parts of Lane County, Oregon.
- The NWS urges drivers to slow down, use low-beam headlights, increase following distance, and pull over safely if visibility nears zero.