Good post. Very interesting. It looks like a phase started in 2013 with the EA. I have said many times that I started noticing an Atlantic-Pacific correlation in 2013, where cold season -NAO's were coinciding with more -PNA/+EPO and +NAO's were coinciding with more +PNA/-EPO. I theorized that it has something to do with the Summer Arctic ice melt, and us not breaking through 2007-2012 levels relative to the global warming. It's like the NAO is "capped" and the potential energy is spilling into other parts of the globe (just my theory). Also 1998 was a big jump up in the EA and that is exactly when the -PDO phase started. The most linear chart I have ever seen, with less flux, is Germany winter snowfall from 50-60 years ago to present. The line almost fits a perfect -30 degree angle. I wonder if the EA index will ever have a negative phase, it appears to be at highest levels all time in 23-24. Upper latitudes should match mid-latitude warming, but that hasn't happened so much lately. AO and NAO and EPO blocks were still higher in the 50s, 60s, 80s, etc. While we keep seeing record breaking ridging 30-50N. I think the NAO not going to record high levels in its blocks is allowing the SE ridge to occur underneath of it, and ridging in Europe, because the base pattern should favor more extreme upper latitude blocks and it's not occurring, if that makes any sense.