The advisory was for Foothills of the Northern Blue Mountains of Oregon, Foothills of the Southern Blue Mountains of Oregon and North Central Oregon.

On Wednesday at 2:28 a.m. the National Weather Service issued a dense fog advisory in effect until 7 a.m. for Salem, Gloucester, Camden and Burlington counties.

On Monday at 9:42 a.m. a dense fog advisory was issued by the National Weather Service in effect until 1 p.m. for Foothills of the Northern Blue Mountains of Oregon, Foothills of the Southern Blue Mountains of Oregon and North Central Oregon.

A dense fog advisory is issued by your local National Weather Service office when widespread dense fog develops. When this happens, visibilities frequ