Dense Fog Advisory issued January 23 at 5:44PM CST until January 24 at 12:00AM CST by NWS

...DENSE FOG ADVISORY IN EFFECT UNTIL MIDNIGHT CST TONIGHT... * WHAT...Visibility one quarter mile or less in dense fog. * WHERE...Portions of southwest and west central Illinois and east central and northeast Missouri. * WHEN...Until midnight CST tonight. * IMPACTS...Low visibility could make driving conditions hazardous.