...DENSE FOG ADVISORY IN EFFECT UNTIL 10 AM CST THIS MORNING... The National Weather Service in Saint Louis has issued a Dense Fog Advisory, which is in effect until 10 AM CST this morning. * TIMING...Dense fog is expected to develop across the area early this morning and is expected to last until late this morning. * VISIBILITIES...Visibilities of one-quarter mile or less at times are expected. * IMPACTS...Rapid changes in visibility will cause hazardous driving conditions. With the temperatures falling below 32 degrees icy spots may develop on bridges and overpasses as the persistent and dense fog droplets freezes on surfaces. 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. Also be prepared for the possibility of icy spots, mainly on untreated bridges and overpasses where the fog freezes on surfaces. &&