Dense Fog Advisory issued August 21 at 8:21AM MDT until August 21 at 10:00AM MDT by NWS

...DENSE FOG SLOWLY CLEARING IN FAR NORTHEAST COLORADO... Fog was lifting over much of northeastern Colorado at 8 am, but was slower to clear in the South Platte river valley and along Interstate 76 between Sterling and Ogallala. The fog extends into Nebraska affecting Chappell and Ogallala and areas north of there, but had cleared around North Platte. The fog will continue

from Current Watches, Warnings and Advisories for the United States Issued by the National Weather Service http://ift.tt/2uYRXf2