National Weather Service United States Department of Commerce

Dense fog will persist this morning. Visibilities at or below 1/4 mile will be common. In some locations there may be rapid changes in visibility over short distances. Temperatures will be below freezing, so the fog could create slick spots on untreated surfaces such as bridges, overpasses, and sidewalks. If you will be traveling this morning, remember to slow down and build in extra time to reach your destination.
Dense fog across the region this morning will gradually dissipate by midday. Otherwise, cloudy skies will prevail today with flurries/sprinkles possible through late this afternoon. No accumulation expected. Highs will range from 32 degrees over northeast MO/west central IL to near 50 degrees over southeast MO.
Accumulating snow is looking increasingly likely Tuesday Night into Wednesday morning. The highest probability for snow is across southern Missouri into southwest Illinois where there is potential for snowfall amounts of 1-2”. There is greater uncertainty on the northern extent of measurable snow, especially along and north of Interstate 70 in Missouri and Interstate 64 in Illinois.