Dense Fog Advisory issued January 23 at 9:36PM CST until January 24 at 12:00PM CST by NWS

...DENSE FOG ADVISORY NOW IN EFFECT UNTIL NOON CST WEDNESDAY... * WHAT...Visibility one quarter mile or less in dense fog. * WHERE...Portions of south central, southwest, and west central Illinois and central, east central, northeast, and southeast Missouri. * WHEN...Until noon CST Wednesday.