A Dense Fog Advisory has been issued for most of northern Illinois through Tuesday morning. With little change in temperatures, light winds and increasing moisture dense fog has developed over northern Illinois and eastern Iowa.
Visibility has lowered over the past couple of hours down to under a mile in a few locations. I anticipate the fog to become even more dense as the evening/night continues, so please use extra caution and give yourself a little extra time for the commute Tuesday morning. An incoming cold front will help get rid of the fog by mid-morning Tuesday.