Trend this evening has been to narrow the band of heavier precip but maintain it for longer through northern Illinois / southern WI. GFS is now showing the same
Looks like NW IL and NE IA will jackpot as the western edge starts to pivot. NE IL will probably get in on it too, expect much of Chicagoland to be 8-10” in the end.
The ECMWF did a pretty good job in the end with this system.