I get that the ascending solar neg NAO correlation was insignificant, but it was technically slightly negative and given the fact that the easterly QBO consideration is significant, I don't think its unreasonable to give at least a slightly disturbed PV the nod in the event that dateline forcing continues. It looked to me that the ascending/neg NAO relationship was pretty stable given a basin wide el nino...of course, if el nino goes nuclear and forcing shifts east, then it's all moot, anyway.
And I am open to hearing why Tonga will have a greater impact in enhancing the PV during an easterly QBO, basin wide el nino than it did during a W QBO modoki la nina last season.