The one thing in common with the years with data above is at least one month during DJF averaging a very strong negative NAO. This forces the storm track to the south resulting in the snowiest seasons.
We are forecasting a negative NAO this winter, with the southern stream being active in the weak El Nino we believe chances will be around for well above average snowfall. However, we only expect the NAO to dip severely negative only in short durations and if it is timed well it could produce a big snow event. But right now we will only go a few inches above. Check back for an update in December!