I am not new to chicago, BUT even though I am not new to driving with summer tires in the snow:
1. I didn't know they wouldnt operate under that stated temperature
2. I had absolutely no idea that it was going to snow at all that night, it was a complete surprise

so
3. I know I am at fault for not being able to stop in time, regardless of whos fault it is, all I know is if I did have the right tires (poor decision at the wrong time) then I would have without question been able to avoid this infraction.

The fine has already been paid for, I was just curious as to what others would say about it, technicalities are irrelevant here since many people are more than sure to say that, if the law says so, its best to just follow it. I just wanted to post up and see what others would say before I finalized my decision.

Thanks!
Jeff.