It could be something with the microphysics scheme within the model itself as well. Not really sure what is going on. I do agree about your previous post though, i.e., this run is much more impressive than other guidance currently.
Look down at South Carolina. The modeled reflectivity never spits out snow, but if you look at the actual snow accumulation field, there is >10 inches. Something is most definitely wrong.
Not sure exactly how his calculation is done; I'm sure it's probably in his paper. But here is a link to Eurasia snow cover for Oct from 1967-2017. 2018 is not updated yet.
https://www.ncdc.noaa.gov/snow-and-ice/extent/snow-cover/eurasia/10