Powerful cold front briefly slams the door on 70° warmth

When I take a look at all that has happened over the last 24 hours, all I have to say is wow. Northern Illinois and southern Wisconsin has seen it all from historic warmth to severe storms, to wind-driven snow to single-digit chills.

What's even more mind-boggling is that temperatures Wednesday afternoon will run a whopping 45° to 50° colder than 24 hours prior. Long story short, that heavier coat that has been collecting dust is going to come in handy throughout the day. 

As the last of yesterday's storm system exits, clouds will decrease into the afternoon. Despite sun-filled skies, much colder air aloft and a cold northwesterly wind will limit highs to the upper 20s.
 
To make matters slightly worse, wind chill values will be stuck in the upper single-digits and the lower teens for much of the day Wednesday. Again, bundle up! With high pressure sitting to our south, skies remain mostly clear overnight, with temperatures falling back in the upper teens before daybreak. 

Forecast models then show this high pressure system shifting to our east by Thursday afternoon. What does this mean? Southwest flow returns.

This will allow temperatures to climb back into the 40s tomorrow, and then low 50s Friday. 

With a weak disturbance sliding into central Illinois, Friday does feature more clouds as well as a slim chance for a passing shower or two.