That stuff is above my pay grade, but I have read some technical papers discussing some of the correlations. Having a near solar min, QBO heading towards neutral(then presumably negative) as we move towards mid winter, and the atmosphere behaving more Nino-ish, should all favor some persistence with HL blocking, esp for late winter. Kind of a bonus that we are seeing the tendency for higher heights in the NAO domain and 50-50 low persistence early in winter.