This to me is the key factor the last 20 years. The displacement of the subtropical belts. Quite often they go so far north that we get the Azores ridge into Greenland but the PFJ has been so far north for a lot of winters recently that its difficult to get those deep cold pools ridging where we would need them to The reasons .. probably as simple as increased SST's Will this winter be cold after a record breaking summer again. I think personally its very very unlikely. However we all now think temps around 4-6c are very cold as were so accustomed to milder conditions