...DENSE FOG ADVISORY NOW IN EFFECT UNTIL 11 AM CST THIS MORNING... * TIMING...Dense fog will persist across parts of Missouri and Illinois. * VISIBILITIES...Visibilities of one-quarter mile or less at times are expected. * IMPACTS...Rapid changes in visibility will cause hazardous driving conditions. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Dense Fog Advisory is issued when dense fog will substantially reduce visibilities... to one-quarter mile or less...resulting in hazardous driving conditions in many areas. Motorists are advised to use caution and slow down... as objects on and near roadways will be seen only at close range. &&