I think we definitely have -AO tendency this Winter. After the arctic ice melt low in 2012, there has been a major difference in the Winters that follow +SLP over the Arctic circle or -SLP in the Summer. It's almost a perfect correlation. low pressure/-SLP has led Winter -AO (a mean ridge at 90N). high pressure/+SLP has led Winter +AO (again, 90N). 90N is actually not a common area to have core anomaly, so when that sticks out like it does in a composite it's something to pay attention to, especially because you are flipping anomalies over the same exact location. We had something like a -8 SLP Jun-Aug signal over the Arctic circle, which is about as extreme as it gets since 2012. I said early on that I think that, and general negative-500mb anomalies up north in the warm season (we also broke the record for lowest 500mb height on record in the N. Hemisphere in August), are leading to a Winter -AO pattern. The problem with pure-negAO dominated patterns is that they sometimes happen with a +PNA low underneath the arctic ridge in the north pacific ocean. That can neutralize the cold signal in the NW, or put a slight ridge there.
Then you have that since the 23-24 Strong Nino, the PNA has not acted the same. 21/29 months since June 2023 have been +PNA (CPC), and since the Strong Nino ended, 12 out of 19 months have been +PNA in slight-negative-ENSO. I've seen all year that when a N. Pacific High builds in it doesn't establish or sustain. Now it's possible that a different pattern may happen for the Winter, since ENSO correlates strongest in Jan-Feb, but maybe there isn't a lot going for a -PNA right now.. Speaking of Phil, he did say that the 23-24 El Nino changed things, and I see that, although he has to clarify because I know that past Strong-Nino's were followed by very La Nina-ish conditions up to 3+ years afterward.
I would say maybe when the MJO is favorable we can get a -PNA pattern, but I would be surprised if it is dominant for the majority of the Winter.
There have been some strong and repeated signals from the Euro Climate a from a few of the AI climate runs of a DJF/JFM negative anomaly axis between Vermont and Florida. Looks pretty interesting for anyone wanting to chase Mid Atlantic or NE snow storms from the second week of December onwards.
Inversely the same ridging signal that a lot of us Seattle snow weenies have been mistaking for Alaska actually has a basis in a very positive anomaly for the far eastern Pacific. I think you called this out early on, so we’re probably going to see a very dry and ridge dominated winter. People forget, but the west coast lowlands has and will have again multi year streaks without any significant cold air that lines up with a Pacific storm track.
Anyway, you’re going to have to pick up the slack now that we are without Phil here anymore to remind us of what reality is.