Dense Fog Advisory issued August 15 at 3:10AM CDT until August 15 at 9:00AM CDT by NWS

...Dense Fog Over Northern Iowa This Morning... .A blanket of dense fog has developed over north central Iowa and looks to continue to remain thick through the remainder of the night time hours. Visibility to less than a quarter mile are likely at times through around 9 AM this morning when the visibility is expected to improve.

from Current Watches, Warnings and Advisories for the United States Issued by the National Weather Service http://ift.tt/2uEJc9W