Blocking is a term used for when a high pressure system stalls out in the upper latitudes. If this blocking can set up in the right places, snow and cold can flow south into North America. However, if this blocking happens to set up in the wrong places, like on the other side of the world, we may encounter trouble with obtaining cold and snow.
Before you get worried about a last year repeat, know this: We are in an ENTIRELY DIFFERENT pattern and scenario in this year compared to last.
Last year, fall was warm and not many cold shots came our way. In that sense, we had a forewarning. Already this fall, we have observed snow and cold throughout the nation- something many did not experience at all last winter. Additionally, this year, the pattern is much more progressive, meaning that there is less of a chance of a ridge staying put for weeks on end this year compared to last.
While this is not something we want to see during the fall and winter, it would be much worse if this blocking were to stick around for days upon days. If that were to happen, we could have a harder time getting some good snow and cold come winter.