I don't know why, but the PNA is more uniform now than it was in the 1960s and 1970s. 3-wave patterns that almost always carry through. I get this from tracking just about every Winter since 2017. I've said it before, storms that models have snow around Day 7-8 with a strong -PNA or +EPO end up rain >90% of the time. Maybe the jet stream is north, maybe it's something with the AMO, but I don't see this storm threat as a close call at all. And I know as we get closer it will trend toward more of a snow miss and rain or nothing. Now if we end up 30 degrees and sunny on that day, I will say you were right - the SE ridge was not underestimated, but that's a strong anomaly in the Pacific! It's not just PNA, it's like 3 standard deviations. In March we get more neutral heights with -PNA but in Feb the SE ridge correlation is still pretty strong:
[default of map below is positive, so negative pna is opposite]