This is what a future potential blizzard looks like on a forecast model 10 days away. If this plot were to verify the Chicago area would escape the worst, we would start off with mostly rain [potentially heavy] then get whats called dry slotted and then perhaps an inch or 2 of snow on the back side of this system as it moves away.
The center of the system is located over C IL, from here and points SW is where the dry slot would form [this is what gives storms those big comma shapes on radar/satellite] so we would expect a break in precip, before the snow moves in on the back side as the system moves in.
Parts of IA/MN/WI are on the "cold side" of the system the entire time and would see the heaviest snow accumulations.
Areas around the MS river and points east could potentially see severe weather in the form of a squall line that brings a wind damage/tornado threat.
BUT, 10 days might as well be an eternity when it comes to forecast model reliability. What is important to take away from this though, is that the forecast model is showing an overall colder and stormier pattern, which suggests our easy winter is about to end. So while this event shown here might not become a reality, overall, the second half of January doesn't look as pleasant as the first half. This is basically how a long range forecast is derived, by looking at trends.