Let’s take a look at the 15-day forecast for Chicago as the super cold arctic air outbreak of early winter 2017-18 departs.
Freezing rain and icing is notorious when arctic air is retreating. Low level cold adhering to snow cover lay beneath milder southerly wind aloft and precipitation falls as rain but refreezes just before reaching the ground. These conditions are occurring in Chicago now. In fact, a winter weather advisory for freezing rain and ice is in effect for the Midwest, Mid-South and Ohio Valley through tonight.
Tomorrow the sun eventually appears in Chicago and temperatures finally rise above freezing. By Wednesday and Thursday a southwest wind brings snow eating warm temperatures near 50 each day. Thursday is rainy but another cold air mass arrives for the weekend as precipitation ends as snow. The next air mass is not unusually cold.
The new chilly air mass lasts into early next week followed by another thaw. This one could be impressive as temperatures surge toward and even past 50 during January 18-21.