Mainly clear skies over eastern Wisconsin will allow for the formation of fog again tonight. The fog will gradually thicken during the evening. Although the visibility at most locations is expected to edge downward to between 1 and 2 miles by midnight...the fog will become much more dense in places. The fog could become thick enough to reduce visibilities to below 1/4 mile in low-lying areas. Anyone traveling this evening should be prepared for the possibility of some dense fog...especially late in the evening. If you encounter a fog bank while driving on the highway...always use your low-beam headlights and slow down to a speed at which you can safely stop if you encounter an animal or object in the roadway.

Partly cloudy. Areas of dense fog reducing visibilities to less than 1/4 mile at times after midnight. Lows 40 to 43. South wind 10 to 15 mph.