A DENSE FOG ADVISORY has been issued for the following counties: Stephenson, Jo Daviess, Carroll and Whiteside until 9am Friday. Dense fog has developed over portions of the area Thursday night, reducing visibility down to under half a mile in some spots.
Temperatures have been close to freezing for most, but are slightly below freezing across northwest Illinois. This means that some of the fog may be freezing on contact to the ground, especially on elevated surfaces such as bridges and overpasses. Be mindful of slick conditions and black ice tonight and Friday morning. Temperatures may fall another degree or two Thursday evening, but will remain pretty steady through the night. A slight dip of the numbers in the upper 20s is possible by Friday morning.