Strong 700mb frontogenetic forcing has overspreaded the area with the forcing aligned nearly parallel to the isotherms at 700mb leading to this intense forcing.  The snowfall rates will exceed 2" locally in some spots, but because of the lack of forcing in the dendritic growth layer and an extended time period above -10C the rates will stay generaaly at or slighlty below 2"/hr.

The sounding below shows the weak upright convective instability that is fueling this heavy band of snow.  The MU layer is approximately 725-700mb with another layer around 675mb.  Can also make the argument for slantwise principles but radar returns do not show this and as we progress through the afternoon the top of conditionally stable layer wil have the winds veer enough to decrease the unidirectional profile of the winds.  

Topeka, KS

First image is around Lawrence, KS and the second around Topeka on 70.  I have been through these areas several of times chasing tornadoes, so it is weird seeing the snow!