AREAS OF DENSE FOG AND LOCALLY SLIPPERY ROADS TONIGHT... Mild, moist air flowing over the snow covered ground will keep areas of dense fog tonight. Visibility may drop below a mile at times, especially across north-central Wisconsin. In addition, light rain could transition over to snow or even freeze on untreated surfaces, creating slick spots late tonight. Use caution if you will be traveling. The dense fog could also result in airline delays tonight and Friday morning.