If driving, slow down, use your headlights, and leave plenty of distance ahead of you.

DENSE FOG ADVISORY IN EFFECT FROM 6 PM THIS EVENING TO 9 AM CST WEDNESDAY... * WHAT...Visibility one quarter mile or less in dense fog. * WHERE...Portions of northwest Illinois and east central, northeast, and southeast Iowa. * WHEN...From 6 PM this evening to 9 AM CST Wednesday. * IMPACTS...Low visibility could make driving conditions hazardous. * ADDITIONAL DETAILS...Dense fog should rapidly develop as the sun sets across the advisory area. The fog could freeze, leading to slick conditions on untreated surfaces. The advisory may need to be extended tomorrow.