Alert Details
Patchy dense fog has formed west of I-55 in central Illinois in the last couple of hours. Visibility may fall below one-quarter mile at times through early morning, leading to potentially hazardous travel conditions. Expect rapid changes in visibility over short distances, with visibility possibly even near zero at times. Be sure to slow down if you encounter dense fog. Use low beam headlights if driving, and leave plenty of distance between you and the vehicle ahead.