Dense Fog Advisory issued May 13 at 5:33AM CDT until May 13 at 8:00AM CDT by NWS St Louis MO

* WHAT...Visibility one quarter mile or less in dense fog.

* WHERE...Portions of south central and southwest Illinois and east
central and southeast Missouri.

* WHEN...Until 8 AM CDT this morning.

* IMPACTS...Low visibility could make driving conditions hazardous.