The advisory is in effect until 10 a.m. A dense fog advisory is issued by your local National Weather Service office when widespread dense fog develops. When this happens, visibilities frequently drop to one-quarter of a mile or less. These conditions make travel difficult. Take extra caution when on the road or avoid driving if possible.

Areas of dense fog will persist through the rest of Monday with areas of visibility less than 1/4 mile throughout southeast Minnesota and northeast Iowa. Once the wind shifts later tonight and Tuesday morning,

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

The NWS San Francisco CA issued a dense fog advisory at 7:17 a.m. on Monday. Visibility one quarter mile or less in dense fog for San Francisco and San Francisco Peninsula Coast until 10 a.m. this morning.