Reduced visibility (National Weather service) Shelby County, IL)

from National Weather service (Lincoln, IL office):

... AREAS OF DENSE FOG THIS MORNING (Feb. 23, 2017)... THE LIGHT WINDS AND ABUNDANT LOW LEVEL MOISTURE HAS RESULTED IN SOME AREAS OF DENSE FOG EARLY THIS MORNING, ESPECIALLY BETWEEN THE ILLINOIS RIVER AND THE I-72 CORRIDOR. VISIBILITY IN SOME LOCATIONS IS DOWN TO A QUARTER MILE OR LESS. THIS FOG SHOULD DISSIPATE LATER THIS MORNING. THE FOG AND VISIBILITY ARE HIGHLY VARIABLE OVER SHORT DISTANCES