Snow Tuesday and Friday followed by arctic cold

Chicagoans will experience a "normal" January day today -- if there is such a thing.
High temperatures rise into the upper 20s, and that's pretty close to the climatological
expectation of 30 degrees on this date.
With seasonably cold air already in place, the next storm system is to be a
snow-producer for Chicago, but a dicey forecast situation is shaping up. The approaching low pressure
system will have tapped moisture from the Gulf of Mexico and therefore has the potential
to generate copious snow totals along and just to the northwest of the path of its low
pressure center. That path is expected to extend from Louisiana to Ohio and then northeast
into New England. Best estimate is that the Chicago area will see snow but remain
northwest of the belt of greatest snow accumulations (across central Illinois and northern
Indiana) late Tuesday into Wednesday morning.
LATE-WEEK SNOW AND ARCTIC BLAST
Another accumulating snow is possible Friday, followed by a powerful surge of air of
arctic origin. That means the weekend's nighttime temperatures are likely to be near or a
few degrees below zero. Chicago logs 10 subzero lows in an average winter.
--By Richard Koeneman, WGN Weather Center Meteorologist