The METARs for 06Z show snow falling in the northern part of Indiana. The GFS 500mb heights for this time frame (red contour) shows the trough that was dipping. The yellow contours show the GFS run from 24hrs before of this time period and had the trough lower over the western part of the state than the eastern. The dashed lines are differential vorticity advection, pink being negative, and blue being positive. The rising motion was occuring East of the precipitation where the snow was moving off toward the east this morning. The positive vorticity advection in the west came through later today, clearing out the clouds and letting sunshine through.