If driving, slow down, use your headlights, and leave plenty ofdistance ahead of you.
* WHAT...Visibility one quarter mile or less in dense fog.* WHERE...In Illinois, Monroe IL County. In Missouri, Jefferson MO,Washington MO, Iron MO, Madison MO, Reynolds MO, Saint FrancoisMO, and Sainte Genevieve MO Counties.* WHEN...Until 9 AM CDT Tuesday.* IMPACTS...Low visibility could make driving conditions hazardous.