Several weather systems are to traverse the Midwest and Great Lakes in coming days. The first will be passing to our north on Monday, spreading snow across the upper Midwest, and prompting winter weather warnings and advisories from North Dakota, to northern Wisconsin. Chicago will lie in damp, relatively mild air until late Monday. An attendant cold front is poised to sweep across the metro area by late afternoon, bringing a push of colder, drier air. Flurries are possible as temperatures drop Monday evening, but measurable snow is not expected. Weak, clipper-type systems are forecast to visit the region Tuesday, and Friday, again keeping any measurable snow well to the north. Mild air has been the rule through the opening 8 days of December, with the month yet to register a below normal day. That is due to change beginning Tuesday, with subfreezing temps expected through midweek.