Chicago weather: Dense Fog Advisory in effect Saturday

CHICAGO - A Dense Fog Advisory was issued for the majority of the Chicago area Saturday morning. 

The National Weather Service says widespread dense fog will continue through mid-morning before gradually improving this afternoon.

Drivers are urged to use extra caution when traveling, slow down, increase following distance and use low-beam headlights. Visibility was reportedly less than a half mile at times. 

The advisory is scheduled to expire at 3 p.m. in Central Cook County, DeKalb County, DuPage County, Eastern Will County, Grundy County, Kane County, Kankakee County, Kendall County, La Salle County, Lake County, McHenry County, Northern Cook County, Northern Will County, Southern Cook County, Southern Will County, Lake County, Newton County, Porter County, and Jasper County.

The high for today will reach 40 degrees.