* WHAT...Visibility 1/4 mile or less in dense fog.
* WHERE...Portions of central Upper and western Upper Michigan.
* WHEN...Until 10 AM EDT /9 AM CDT/ this morning.
* IMPACTS...Low visibility could make driving conditions hazardous.
* ADDITIONAL DETAILS...Areas along the Lake Superior shoreline can expect less in the way of fog due to light, southerly downslope flow. Be prepared for rapidly changing conditions if you are headed inland.