Dense Fog Advisory issued August 15 at 4:53AM CDT until August 15 at 9:00AM CDT by NWS

...Dense Fog Continues Over Northern Iowa This Morning... .A blanket of dense fog will continue to spread south and east this morning over north central Iowa and looks to remain thick through the mid morning 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/2uKFvve