>I know I have been silent as I look at information, but I have decided that is not fair, and you should know what I know.
At this time, the 00z ECMWF model took the low across Iowa, then dipped southeast into Central IL. People in Chicago and Madison would be in the line for rain or sleet as the thickness line sits in Central Wisconsin, but with the 5410 line (5400 is the freezing point) way down south, I believe rain will not be the dominant feature if the ECMWF has its way.
The 06z GFS model has a low move across the WI/IL border. However, it is weaker than other models and eventually takes a funny turn south.
The 00z NOGAPS Model was looking to take a very southern track, when the low projected on NOGAPS suddenly stopped. The energy appeared to continue forward, however. In that time frame, the rain/snow line was on the Wisconsin Illinois border. Chicago would likely receive freezing rain or sleet, while Madison, WI would receive snow and mixed sleet. Later in the model run, the low pressure, seemingly weaker, began to trek across Central Illinois. However, the rain/snow line was now in line with the south tip of Lake Michigan. The low pressure still had abundant precipitation. Chicago would receive snow with mixed sleet and Madison would receive all snow if this situation panned out.
The 00z CMC (GEM) Model had the low pressure move along South Wisconsin with the thickness line right against the low.The low also appeared much faster, so less precipitation would fall.
Conclusion: The GFS is a model that may significantly change. In the meanwhile,the other models will battle for supremacy.